mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2025-10-30 22:32:25 -05:00
1999 lines
56 KiB
Go
1999 lines
56 KiB
Go
// Copyright © 2015 The Go Authors. All rights reserved.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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package riscv
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import (
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"github.com/twitchyliquid64/golang-asm/obj"
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"github.com/twitchyliquid64/golang-asm/objabi"
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"github.com/twitchyliquid64/golang-asm/sys"
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"fmt"
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)
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func buildop(ctxt *obj.Link) {}
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// jalrToSym replaces p with a set of Progs needed to jump to the Sym in p.
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// lr is the link register to use for the JALR.
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// p must be a CALL, JMP or RET.
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func jalrToSym(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc, lr int16) *obj.Prog {
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if p.As != obj.ACALL && p.As != obj.AJMP && p.As != obj.ARET {
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ctxt.Diag("unexpected Prog in jalrToSym: %v", p)
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return p
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}
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// TODO(jsing): Consider using a single JAL instruction and teaching
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// the linker to provide trampolines for the case where the destination
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// offset is too large. This would potentially reduce instructions for
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// the common case, but would require three instructions to go via the
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// trampoline.
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to := p.To
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p.As = AAUIPC
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p.Mark |= NEED_PCREL_ITYPE_RELOC
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p.RestArgs = []obj.Addr{obj.Addr{Type: obj.TYPE_CONST, Offset: to.Offset, Sym: to.Sym}}
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: 0}
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p.Reg = 0
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p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
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p = obj.Appendp(p, newprog)
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// Leave Sym only for the CALL reloc in assemble.
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p.As = AJALR
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p.From.Type = obj.TYPE_REG
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p.From.Reg = lr
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p.Reg = 0
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p.To.Type = obj.TYPE_REG
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p.To.Reg = REG_TMP
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p.To.Sym = to.Sym
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return p
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}
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// progedit is called individually for each *obj.Prog. It normalizes instruction
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// formats and eliminates as many pseudo-instructions as possible.
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func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
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// Expand binary instructions to ternary ones.
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if p.Reg == 0 {
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switch p.As {
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case AADDI, ASLTI, ASLTIU, AANDI, AORI, AXORI, ASLLI, ASRLI, ASRAI,
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AADD, AAND, AOR, AXOR, ASLL, ASRL, ASUB, ASRA,
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AMUL, AMULH, AMULHU, AMULHSU, AMULW, ADIV, ADIVU, ADIVW, ADIVUW,
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AREM, AREMU, AREMW, AREMUW:
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p.Reg = p.To.Reg
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}
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}
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// Rewrite instructions with constant operands to refer to the immediate
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// form of the instruction.
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if p.From.Type == obj.TYPE_CONST {
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switch p.As {
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case AADD:
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p.As = AADDI
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case ASLT:
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p.As = ASLTI
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case ASLTU:
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p.As = ASLTIU
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case AAND:
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p.As = AANDI
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case AOR:
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p.As = AORI
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case AXOR:
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p.As = AXORI
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case ASLL:
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p.As = ASLLI
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case ASRL:
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p.As = ASRLI
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case ASRA:
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p.As = ASRAI
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}
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}
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switch p.As {
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case obj.AJMP:
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// Turn JMP into JAL ZERO or JALR ZERO.
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p.From.Type = obj.TYPE_REG
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p.From.Reg = REG_ZERO
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switch p.To.Type {
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case obj.TYPE_BRANCH:
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p.As = AJAL
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case obj.TYPE_MEM:
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switch p.To.Name {
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case obj.NAME_NONE:
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p.As = AJALR
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case obj.NAME_EXTERN:
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// Handled in preprocess.
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default:
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ctxt.Diag("unsupported name %d for %v", p.To.Name, p)
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}
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default:
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panic(fmt.Sprintf("unhandled type %+v", p.To.Type))
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}
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case obj.ACALL:
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switch p.To.Type {
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case obj.TYPE_MEM:
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// Handled in preprocess.
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case obj.TYPE_REG:
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p.As = AJALR
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p.From.Type = obj.TYPE_REG
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p.From.Reg = REG_LR
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default:
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ctxt.Diag("unknown destination type %+v in CALL: %v", p.To.Type, p)
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}
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case obj.AUNDEF:
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p.As = AEBREAK
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case ASCALL:
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// SCALL is the old name for ECALL.
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p.As = AECALL
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case ASBREAK:
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// SBREAK is the old name for EBREAK.
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p.As = AEBREAK
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}
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}
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// addrToReg extracts the register from an Addr, handling special Addr.Names.
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func addrToReg(a obj.Addr) int16 {
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switch a.Name {
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case obj.NAME_PARAM, obj.NAME_AUTO:
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return REG_SP
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}
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return a.Reg
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}
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// movToLoad converts a MOV mnemonic into the corresponding load instruction.
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func movToLoad(mnemonic obj.As) obj.As {
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switch mnemonic {
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case AMOV:
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return ALD
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case AMOVB:
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return ALB
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case AMOVH:
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return ALH
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case AMOVW:
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return ALW
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case AMOVBU:
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return ALBU
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case AMOVHU:
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return ALHU
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case AMOVWU:
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return ALWU
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case AMOVF:
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return AFLW
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case AMOVD:
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return AFLD
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default:
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panic(fmt.Sprintf("%+v is not a MOV", mnemonic))
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}
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}
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// movToStore converts a MOV mnemonic into the corresponding store instruction.
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func movToStore(mnemonic obj.As) obj.As {
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switch mnemonic {
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case AMOV:
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return ASD
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case AMOVB:
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return ASB
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case AMOVH:
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return ASH
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case AMOVW:
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return ASW
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case AMOVF:
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return AFSW
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case AMOVD:
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return AFSD
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default:
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panic(fmt.Sprintf("%+v is not a MOV", mnemonic))
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}
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}
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// rewriteMOV rewrites MOV pseudo-instructions.
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func rewriteMOV(ctxt *obj.Link, newprog obj.ProgAlloc, p *obj.Prog) {
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switch p.As {
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case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
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default:
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panic(fmt.Sprintf("%+v is not a MOV pseudo-instruction", p.As))
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}
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switch p.From.Type {
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case obj.TYPE_MEM: // MOV c(Rs), Rd -> L $c, Rs, Rd
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switch p.From.Name {
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case obj.NAME_AUTO, obj.NAME_PARAM, obj.NAME_NONE:
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if p.To.Type != obj.TYPE_REG {
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ctxt.Diag("unsupported load at %v", p)
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}
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p.As = movToLoad(p.As)
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p.From.Reg = addrToReg(p.From)
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case obj.NAME_EXTERN, obj.NAME_STATIC:
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// AUIPC $off_hi, R
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// L $off_lo, R
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as := p.As
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to := p.To
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p.As = AAUIPC
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p.Mark |= NEED_PCREL_ITYPE_RELOC
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p.RestArgs = []obj.Addr{obj.Addr{Type: obj.TYPE_CONST, Offset: p.From.Offset, Sym: p.From.Sym}}
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: 0}
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p.Reg = 0
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p.To = obj.Addr{Type: obj.TYPE_REG, Reg: to.Reg}
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p = obj.Appendp(p, newprog)
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p.As = movToLoad(as)
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p.From = obj.Addr{Type: obj.TYPE_MEM, Reg: to.Reg, Offset: 0}
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p.To = to
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default:
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ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
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}
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case obj.TYPE_REG:
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switch p.To.Type {
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case obj.TYPE_REG:
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switch p.As {
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case AMOV: // MOV Ra, Rb -> ADDI $0, Ra, Rb
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p.As = AADDI
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p.Reg = p.From.Reg
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p.From = obj.Addr{Type: obj.TYPE_CONST}
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case AMOVF: // MOVF Ra, Rb -> FSGNJS Ra, Ra, Rb
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p.As = AFSGNJS
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p.Reg = p.From.Reg
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case AMOVD: // MOVD Ra, Rb -> FSGNJD Ra, Ra, Rb
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p.As = AFSGNJD
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p.Reg = p.From.Reg
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default:
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ctxt.Diag("unsupported register-register move at %v", p)
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}
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case obj.TYPE_MEM: // MOV Rs, c(Rd) -> S $c, Rs, Rd
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switch p.As {
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case AMOVBU, AMOVHU, AMOVWU:
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ctxt.Diag("unsupported unsigned store at %v", p)
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}
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switch p.To.Name {
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case obj.NAME_AUTO, obj.NAME_PARAM, obj.NAME_NONE:
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p.As = movToStore(p.As)
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p.To.Reg = addrToReg(p.To)
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case obj.NAME_EXTERN:
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// AUIPC $off_hi, TMP
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// S $off_lo, TMP, R
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as := p.As
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from := p.From
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p.As = AAUIPC
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p.Mark |= NEED_PCREL_STYPE_RELOC
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p.RestArgs = []obj.Addr{obj.Addr{Type: obj.TYPE_CONST, Offset: p.To.Offset, Sym: p.To.Sym}}
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: 0}
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p.Reg = 0
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p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
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p = obj.Appendp(p, newprog)
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p.As = movToStore(as)
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p.From = from
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p.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_TMP, Offset: 0}
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default:
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ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
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}
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default:
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ctxt.Diag("unsupported MOV at %v", p)
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}
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case obj.TYPE_CONST:
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// MOV $c, R
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// If c is small enough, convert to:
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// ADD $c, ZERO, R
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// If not, convert to:
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// LUI top20bits(c), R
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// ADD bottom12bits(c), R, R
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if p.As != AMOV {
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ctxt.Diag("unsupported constant load at %v", p)
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}
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off := p.From.Offset
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to := p.To
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low, high, err := Split32BitImmediate(off)
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if err != nil {
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ctxt.Diag("%v: constant %d too large: %v", p, off, err)
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}
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// LUI is only necessary if the offset doesn't fit in 12-bits.
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needLUI := high != 0
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if needLUI {
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p.As = ALUI
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p.To = to
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// Pass top 20 bits to LUI.
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: high}
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p = obj.Appendp(p, newprog)
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}
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p.As = AADDIW
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p.To = to
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: low}
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p.Reg = REG_ZERO
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if needLUI {
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p.Reg = to.Reg
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}
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case obj.TYPE_ADDR: // MOV $sym+off(SP/SB), R
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if p.To.Type != obj.TYPE_REG || p.As != AMOV {
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ctxt.Diag("unsupported addr MOV at %v", p)
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}
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switch p.From.Name {
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case obj.NAME_EXTERN, obj.NAME_STATIC:
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// AUIPC $off_hi, R
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// ADDI $off_lo, R
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to := p.To
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p.As = AAUIPC
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p.Mark |= NEED_PCREL_ITYPE_RELOC
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p.RestArgs = []obj.Addr{obj.Addr{Type: obj.TYPE_CONST, Offset: p.From.Offset, Sym: p.From.Sym}}
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p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: 0}
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p.Reg = 0
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p.To = to
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p = obj.Appendp(p, newprog)
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p.As = AADDI
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p.From = obj.Addr{Type: obj.TYPE_CONST}
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p.Reg = to.Reg
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p.To = to
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case obj.NAME_PARAM, obj.NAME_AUTO:
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p.As = AADDI
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p.Reg = REG_SP
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p.From.Type = obj.TYPE_CONST
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case obj.NAME_NONE:
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p.As = AADDI
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p.Reg = p.From.Reg
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p.From.Type = obj.TYPE_CONST
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p.From.Reg = 0
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default:
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ctxt.Diag("bad addr MOV from name %v at %v", p.From.Name, p)
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}
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default:
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ctxt.Diag("unsupported MOV at %v", p)
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}
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}
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// InvertBranch inverts the condition of a conditional branch.
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func InvertBranch(as obj.As) obj.As {
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switch as {
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case ABEQ:
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return ABNE
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case ABEQZ:
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return ABNEZ
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case ABGE:
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return ABLT
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case ABGEU:
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return ABLTU
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case ABGEZ:
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return ABLTZ
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case ABGT:
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return ABLE
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case ABGTU:
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return ABLEU
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case ABGTZ:
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return ABLEZ
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case ABLE:
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return ABGT
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case ABLEU:
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return ABGTU
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case ABLEZ:
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return ABGTZ
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case ABLT:
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return ABGE
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case ABLTU:
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return ABGEU
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case ABLTZ:
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return ABGEZ
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case ABNE:
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return ABEQ
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case ABNEZ:
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return ABEQZ
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default:
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panic("InvertBranch: not a branch")
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}
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}
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// containsCall reports whether the symbol contains a CALL (or equivalent)
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// instruction. Must be called after progedit.
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func containsCall(sym *obj.LSym) bool {
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// CALLs are CALL or JAL(R) with link register LR.
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for p := sym.Func.Text; p != nil; p = p.Link {
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switch p.As {
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case obj.ACALL:
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return true
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case AJAL, AJALR:
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if p.From.Type == obj.TYPE_REG && p.From.Reg == REG_LR {
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return true
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}
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}
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}
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return false
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}
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// setPCs sets the Pc field in all instructions reachable from p.
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// It uses pc as the initial value.
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func setPCs(p *obj.Prog, pc int64) {
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for ; p != nil; p = p.Link {
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p.Pc = pc
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for _, ins := range instructionsForProg(p) {
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pc += int64(ins.length())
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}
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}
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}
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// stackOffset updates Addr offsets based on the current stack size.
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//
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// The stack looks like:
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// -------------------
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// | |
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// | PARAMs |
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// | |
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// | |
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// -------------------
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// | Parent RA | SP on function entry
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// -------------------
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// | |
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// | |
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// | AUTOs |
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// | |
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// | |
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// -------------------
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// | RA | SP during function execution
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// -------------------
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//
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// FixedFrameSize makes other packages aware of the space allocated for RA.
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//
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// A nicer version of this diagram can be found on slide 21 of the presentation
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// attached to:
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//
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// https://golang.org/issue/16922#issuecomment-243748180
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//
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func stackOffset(a *obj.Addr, stacksize int64) {
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switch a.Name {
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case obj.NAME_AUTO:
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// Adjust to the top of AUTOs.
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a.Offset += stacksize
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case obj.NAME_PARAM:
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// Adjust to the bottom of PARAMs.
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a.Offset += stacksize + 8
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}
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}
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// preprocess generates prologue and epilogue code, computes PC-relative branch
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// and jump offsets, and resolves pseudo-registers.
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//
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// preprocess is called once per linker symbol.
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//
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// When preprocess finishes, all instructions in the symbol are either
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// concrete, real RISC-V instructions or directive pseudo-ops like TEXT,
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// PCDATA, and FUNCDATA.
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func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
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if cursym.Func.Text == nil || cursym.Func.Text.Link == nil {
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return
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}
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// Generate the prologue.
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text := cursym.Func.Text
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if text.As != obj.ATEXT {
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ctxt.Diag("preprocess: found symbol that does not start with TEXT directive")
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return
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}
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stacksize := text.To.Offset
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if stacksize == -8 {
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// Historical way to mark NOFRAME.
|
|
text.From.Sym.Set(obj.AttrNoFrame, true)
|
|
stacksize = 0
|
|
}
|
|
if stacksize < 0 {
|
|
ctxt.Diag("negative frame size %d - did you mean NOFRAME?", stacksize)
|
|
}
|
|
if text.From.Sym.NoFrame() {
|
|
if stacksize != 0 {
|
|
ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", stacksize)
|
|
}
|
|
}
|
|
|
|
if !containsCall(cursym) {
|
|
text.From.Sym.Set(obj.AttrLeaf, true)
|
|
if stacksize == 0 {
|
|
// A leaf function with no locals has no frame.
|
|
text.From.Sym.Set(obj.AttrNoFrame, true)
|
|
}
|
|
}
|
|
|
|
// Save LR unless there is no frame.
|
|
if !text.From.Sym.NoFrame() {
|
|
stacksize += ctxt.FixedFrameSize()
|
|
}
|
|
|
|
cursym.Func.Args = text.To.Val.(int32)
|
|
cursym.Func.Locals = int32(stacksize)
|
|
|
|
prologue := text
|
|
|
|
if !cursym.Func.Text.From.Sym.NoSplit() {
|
|
prologue = stacksplit(ctxt, prologue, cursym, newprog, stacksize) // emit split check
|
|
}
|
|
|
|
if stacksize != 0 {
|
|
prologue = ctxt.StartUnsafePoint(prologue, newprog)
|
|
|
|
// Actually save LR.
|
|
prologue = obj.Appendp(prologue, newprog)
|
|
prologue.As = AMOV
|
|
prologue.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR}
|
|
prologue.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_SP, Offset: -stacksize}
|
|
|
|
// Insert stack adjustment.
|
|
prologue = obj.Appendp(prologue, newprog)
|
|
prologue.As = AADDI
|
|
prologue.From = obj.Addr{Type: obj.TYPE_CONST, Offset: -stacksize}
|
|
prologue.Reg = REG_SP
|
|
prologue.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_SP}
|
|
prologue.Spadj = int32(stacksize)
|
|
|
|
prologue = ctxt.EndUnsafePoint(prologue, newprog, -1)
|
|
}
|
|
|
|
if cursym.Func.Text.From.Sym.Wrapper() {
|
|
// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
|
|
//
|
|
// MOV g_panic(g), X11
|
|
// BNE X11, ZERO, adjust
|
|
// end:
|
|
// NOP
|
|
// ...rest of function..
|
|
// adjust:
|
|
// MOV panic_argp(X11), X12
|
|
// ADD $(autosize+FIXED_FRAME), SP, X13
|
|
// BNE X12, X13, end
|
|
// ADD $FIXED_FRAME, SP, X12
|
|
// MOV X12, panic_argp(X11)
|
|
// JMP end
|
|
//
|
|
// The NOP is needed to give the jumps somewhere to land.
|
|
|
|
ldpanic := obj.Appendp(prologue, newprog)
|
|
|
|
ldpanic.As = AMOV
|
|
ldpanic.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REGG, Offset: 4 * int64(ctxt.Arch.PtrSize)} // G.panic
|
|
ldpanic.Reg = 0
|
|
ldpanic.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X11}
|
|
|
|
bneadj := obj.Appendp(ldpanic, newprog)
|
|
bneadj.As = ABNE
|
|
bneadj.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X11}
|
|
bneadj.Reg = REG_ZERO
|
|
bneadj.To.Type = obj.TYPE_BRANCH
|
|
|
|
endadj := obj.Appendp(bneadj, newprog)
|
|
endadj.As = obj.ANOP
|
|
|
|
last := endadj
|
|
for last.Link != nil {
|
|
last = last.Link
|
|
}
|
|
|
|
getargp := obj.Appendp(last, newprog)
|
|
getargp.As = AMOV
|
|
getargp.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_X11, Offset: 0} // Panic.argp
|
|
getargp.Reg = 0
|
|
getargp.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X12}
|
|
|
|
bneadj.To.SetTarget(getargp)
|
|
|
|
calcargp := obj.Appendp(getargp, newprog)
|
|
calcargp.As = AADDI
|
|
calcargp.From = obj.Addr{Type: obj.TYPE_CONST, Offset: stacksize + ctxt.FixedFrameSize()}
|
|
calcargp.Reg = REG_SP
|
|
calcargp.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X13}
|
|
|
|
testargp := obj.Appendp(calcargp, newprog)
|
|
testargp.As = ABNE
|
|
testargp.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X12}
|
|
testargp.Reg = REG_X13
|
|
testargp.To.Type = obj.TYPE_BRANCH
|
|
testargp.To.SetTarget(endadj)
|
|
|
|
adjargp := obj.Appendp(testargp, newprog)
|
|
adjargp.As = AADDI
|
|
adjargp.From = obj.Addr{Type: obj.TYPE_CONST, Offset: int64(ctxt.Arch.PtrSize)}
|
|
adjargp.Reg = REG_SP
|
|
adjargp.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X12}
|
|
|
|
setargp := obj.Appendp(adjargp, newprog)
|
|
setargp.As = AMOV
|
|
setargp.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_X12}
|
|
setargp.Reg = 0
|
|
setargp.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_X11, Offset: 0} // Panic.argp
|
|
|
|
godone := obj.Appendp(setargp, newprog)
|
|
godone.As = AJAL
|
|
godone.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
|
|
godone.To.Type = obj.TYPE_BRANCH
|
|
godone.To.SetTarget(endadj)
|
|
}
|
|
|
|
// Update stack-based offsets.
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
stackOffset(&p.From, stacksize)
|
|
stackOffset(&p.To, stacksize)
|
|
}
|
|
|
|
// Additional instruction rewriting.
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
case obj.AGETCALLERPC:
|
|
if cursym.Leaf() {
|
|
// MOV LR, Rd
|
|
p.As = AMOV
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_LR
|
|
} else {
|
|
// MOV (RSP), Rd
|
|
p.As = AMOV
|
|
p.From.Type = obj.TYPE_MEM
|
|
p.From.Reg = REG_SP
|
|
}
|
|
|
|
case obj.ACALL:
|
|
switch p.To.Type {
|
|
case obj.TYPE_MEM:
|
|
jalrToSym(ctxt, p, newprog, REG_LR)
|
|
}
|
|
|
|
case obj.AJMP:
|
|
switch p.To.Type {
|
|
case obj.TYPE_MEM:
|
|
switch p.To.Name {
|
|
case obj.NAME_EXTERN:
|
|
// JMP to symbol.
|
|
jalrToSym(ctxt, p, newprog, REG_ZERO)
|
|
}
|
|
}
|
|
|
|
case obj.ARET:
|
|
// Replace RET with epilogue.
|
|
retJMP := p.To.Sym
|
|
|
|
if stacksize != 0 {
|
|
// Restore LR.
|
|
p.As = AMOV
|
|
p.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_SP, Offset: 0}
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR}
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = AADDI
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: stacksize}
|
|
p.Reg = REG_SP
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_SP}
|
|
p.Spadj = int32(-stacksize)
|
|
p = obj.Appendp(p, newprog)
|
|
}
|
|
|
|
if retJMP != nil {
|
|
p.As = obj.ARET
|
|
p.To.Sym = retJMP
|
|
p = jalrToSym(ctxt, p, newprog, REG_ZERO)
|
|
} else {
|
|
p.As = AJALR
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
|
|
p.Reg = 0
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR}
|
|
}
|
|
|
|
// "Add back" the stack removed in the previous instruction.
|
|
//
|
|
// This is to avoid confusing pctospadj, which sums
|
|
// Spadj from function entry to each PC, and shouldn't
|
|
// count adjustments from earlier epilogues, since they
|
|
// won't affect later PCs.
|
|
p.Spadj = int32(stacksize)
|
|
|
|
case AADDI:
|
|
// Refine Spadjs account for adjustment via ADDI instruction.
|
|
if p.To.Type == obj.TYPE_REG && p.To.Reg == REG_SP && p.From.Type == obj.TYPE_CONST {
|
|
p.Spadj = int32(-p.From.Offset)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Rewrite MOV pseudo-instructions. This cannot be done in
|
|
// progedit, as SP offsets need to be applied before we split
|
|
// up some of the Addrs.
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
|
|
rewriteMOV(ctxt, newprog, p)
|
|
}
|
|
}
|
|
|
|
// Split immediates larger than 12-bits.
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
// <opi> $imm, REG, TO
|
|
case AADDI, AANDI, AORI, AXORI:
|
|
// LUI $high, TMP
|
|
// ADDI $low, TMP, TMP
|
|
// <op> TMP, REG, TO
|
|
q := *p
|
|
low, high, err := Split32BitImmediate(p.From.Offset)
|
|
if err != nil {
|
|
ctxt.Diag("%v: constant %d too large", p, p.From.Offset, err)
|
|
}
|
|
if high == 0 {
|
|
break // no need to split
|
|
}
|
|
|
|
p.As = ALUI
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: high}
|
|
p.Reg = 0
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p.Spadj = 0 // needed if TO is SP
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = AADDIW
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: low}
|
|
p.Reg = REG_TMP
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
switch q.As {
|
|
case AADDI:
|
|
p.As = AADD
|
|
case AANDI:
|
|
p.As = AAND
|
|
case AORI:
|
|
p.As = AOR
|
|
case AXORI:
|
|
p.As = AXOR
|
|
default:
|
|
ctxt.Diag("unsupported instruction %v for splitting", q)
|
|
}
|
|
p.Spadj = q.Spadj
|
|
p.To = q.To
|
|
p.Reg = q.Reg
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
|
|
// <load> $imm, REG, TO (load $imm+(REG), TO)
|
|
case ALD, ALB, ALH, ALW, ALBU, ALHU, ALWU, AFLW, AFLD:
|
|
low, high, err := Split32BitImmediate(p.From.Offset)
|
|
if err != nil {
|
|
ctxt.Diag("%v: constant %d too large", p, p.From.Offset)
|
|
}
|
|
if high == 0 {
|
|
break // no need to split
|
|
}
|
|
q := *p
|
|
|
|
// LUI $high, TMP
|
|
// ADD TMP, REG, TMP
|
|
// <load> $low, TMP, TO
|
|
p.As = ALUI
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: high}
|
|
p.Reg = 0
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p.Spadj = 0 // needed if TO is SP
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = AADD
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p.Reg = q.From.Reg
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = q.As
|
|
p.To = q.To
|
|
p.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_TMP, Offset: low}
|
|
p.Reg = obj.REG_NONE
|
|
|
|
// <store> $imm, REG, TO (store $imm+(TO), REG)
|
|
case ASD, ASB, ASH, ASW, AFSW, AFSD:
|
|
low, high, err := Split32BitImmediate(p.To.Offset)
|
|
if err != nil {
|
|
ctxt.Diag("%v: constant %d too large", p, p.To.Offset)
|
|
}
|
|
if high == 0 {
|
|
break // no need to split
|
|
}
|
|
q := *p
|
|
|
|
// LUI $high, TMP
|
|
// ADD TMP, TO, TMP
|
|
// <store> $low, REG, TMP
|
|
p.As = ALUI
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: high}
|
|
p.Reg = 0
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p.Spadj = 0 // needed if TO is SP
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = AADD
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p.Reg = q.To.Reg
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
p = obj.Appendp(p, newprog)
|
|
|
|
p.As = q.As
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: q.From.Reg, Offset: 0}
|
|
p.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REG_TMP, Offset: low}
|
|
}
|
|
}
|
|
|
|
// Compute instruction addresses. Once we do that, we need to check for
|
|
// overextended jumps and branches. Within each iteration, Pc differences
|
|
// are always lower bounds (since the program gets monotonically longer,
|
|
// a fixed point will be reached). No attempt to handle functions > 2GiB.
|
|
for {
|
|
rescan := false
|
|
setPCs(cursym.Func.Text, 0)
|
|
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
case ABEQ, ABEQZ, ABGE, ABGEU, ABGEZ, ABGT, ABGTU, ABGTZ, ABLE, ABLEU, ABLEZ, ABLT, ABLTU, ABLTZ, ABNE, ABNEZ:
|
|
if p.To.Type != obj.TYPE_BRANCH {
|
|
panic("assemble: instruction with branch-like opcode lacks destination")
|
|
}
|
|
offset := p.To.Target().Pc - p.Pc
|
|
if offset < -4096 || 4096 <= offset {
|
|
// Branch is long. Replace it with a jump.
|
|
jmp := obj.Appendp(p, newprog)
|
|
jmp.As = AJAL
|
|
jmp.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
|
|
jmp.To = obj.Addr{Type: obj.TYPE_BRANCH}
|
|
jmp.To.SetTarget(p.To.Target())
|
|
|
|
p.As = InvertBranch(p.As)
|
|
p.To.SetTarget(jmp.Link)
|
|
|
|
// We may have made previous branches too long,
|
|
// so recheck them.
|
|
rescan = true
|
|
}
|
|
case AJAL:
|
|
if p.To.Target() == nil {
|
|
panic("intersymbol jumps should be expressed as AUIPC+JALR")
|
|
}
|
|
offset := p.To.Target().Pc - p.Pc
|
|
if offset < -(1<<20) || (1<<20) <= offset {
|
|
// Replace with 2-instruction sequence. This assumes
|
|
// that TMP is not live across J instructions, since
|
|
// it is reserved by SSA.
|
|
jmp := obj.Appendp(p, newprog)
|
|
jmp.As = AJALR
|
|
jmp.From = p.From
|
|
jmp.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
|
|
// p.From is not generally valid, however will be
|
|
// fixed up in the next loop.
|
|
p.As = AAUIPC
|
|
p.From = obj.Addr{Type: obj.TYPE_BRANCH, Sym: p.From.Sym}
|
|
p.From.SetTarget(p.To.Target())
|
|
p.Reg = 0
|
|
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
|
|
|
|
rescan = true
|
|
}
|
|
}
|
|
}
|
|
|
|
if !rescan {
|
|
break
|
|
}
|
|
}
|
|
|
|
// Now that there are no long branches, resolve branch and jump targets.
|
|
// At this point, instruction rewriting which changes the number of
|
|
// instructions will break everything--don't do it!
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
case ABEQ, ABEQZ, ABGE, ABGEU, ABGEZ, ABGT, ABGTU, ABGTZ, ABLE, ABLEU, ABLEZ, ABLT, ABLTU, ABLTZ, ABNE, ABNEZ, AJAL:
|
|
switch p.To.Type {
|
|
case obj.TYPE_BRANCH:
|
|
p.To.Type, p.To.Offset = obj.TYPE_CONST, p.To.Target().Pc-p.Pc
|
|
case obj.TYPE_MEM:
|
|
panic("unhandled type")
|
|
}
|
|
|
|
case AAUIPC:
|
|
if p.From.Type == obj.TYPE_BRANCH {
|
|
low, high, err := Split32BitImmediate(p.From.Target().Pc - p.Pc)
|
|
if err != nil {
|
|
ctxt.Diag("%v: jump displacement %d too large", p, p.To.Target().Pc-p.Pc)
|
|
}
|
|
p.From = obj.Addr{Type: obj.TYPE_CONST, Offset: high, Sym: cursym}
|
|
p.Link.From.Offset = low
|
|
}
|
|
}
|
|
}
|
|
|
|
// Validate all instructions - this provides nice error messages.
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
for _, ins := range instructionsForProg(p) {
|
|
ins.validate(ctxt)
|
|
}
|
|
}
|
|
}
|
|
|
|
func stacksplit(ctxt *obj.Link, p *obj.Prog, cursym *obj.LSym, newprog obj.ProgAlloc, framesize int64) *obj.Prog {
|
|
// Leaf function with no frame is effectively NOSPLIT.
|
|
if framesize == 0 {
|
|
return p
|
|
}
|
|
|
|
// MOV g_stackguard(g), X10
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = AMOV
|
|
p.From.Type = obj.TYPE_MEM
|
|
p.From.Reg = REGG
|
|
p.From.Offset = 2 * int64(ctxt.Arch.PtrSize) // G.stackguard0
|
|
if cursym.CFunc() {
|
|
p.From.Offset = 3 * int64(ctxt.Arch.PtrSize) // G.stackguard1
|
|
}
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X10
|
|
|
|
var to_done, to_more *obj.Prog
|
|
|
|
if framesize <= objabi.StackSmall {
|
|
// small stack: SP < stackguard
|
|
// BLTU SP, stackguard, done
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = ABLTU
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_X10
|
|
p.Reg = REG_SP
|
|
p.To.Type = obj.TYPE_BRANCH
|
|
to_done = p
|
|
} else if framesize <= objabi.StackBig {
|
|
// large stack: SP-framesize < stackguard-StackSmall
|
|
// ADD $-(framesize-StackSmall), SP, X11
|
|
// BLTU X11, stackguard, done
|
|
p = obj.Appendp(p, newprog)
|
|
// TODO(sorear): logic inconsistent with comment, but both match all non-x86 arches
|
|
p.As = AADDI
|
|
p.From.Type = obj.TYPE_CONST
|
|
p.From.Offset = -(int64(framesize) - objabi.StackSmall)
|
|
p.Reg = REG_SP
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X11
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = ABLTU
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_X10
|
|
p.Reg = REG_X11
|
|
p.To.Type = obj.TYPE_BRANCH
|
|
to_done = p
|
|
} else {
|
|
// Such a large stack we need to protect against wraparound.
|
|
// If SP is close to zero:
|
|
// SP-stackguard+StackGuard <= framesize + (StackGuard-StackSmall)
|
|
// The +StackGuard on both sides is required to keep the left side positive:
|
|
// SP is allowed to be slightly below stackguard. See stack.h.
|
|
//
|
|
// Preemption sets stackguard to StackPreempt, a very large value.
|
|
// That breaks the math above, so we have to check for that explicitly.
|
|
// // stackguard is X10
|
|
// MOV $StackPreempt, X11
|
|
// BEQ X10, X11, more
|
|
// ADD $StackGuard, SP, X11
|
|
// SUB X10, X11
|
|
// MOV $(framesize+(StackGuard-StackSmall)), X10
|
|
// BGTU X11, X10, done
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = AMOV
|
|
p.From.Type = obj.TYPE_CONST
|
|
p.From.Offset = objabi.StackPreempt
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X11
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
to_more = p
|
|
p.As = ABEQ
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_X10
|
|
p.Reg = REG_X11
|
|
p.To.Type = obj.TYPE_BRANCH
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = AADDI
|
|
p.From.Type = obj.TYPE_CONST
|
|
p.From.Offset = int64(objabi.StackGuard)
|
|
p.Reg = REG_SP
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X11
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = ASUB
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_X10
|
|
p.Reg = REG_X11
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X11
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = AMOV
|
|
p.From.Type = obj.TYPE_CONST
|
|
p.From.Offset = int64(framesize) + int64(objabi.StackGuard) - objabi.StackSmall
|
|
p.To.Type = obj.TYPE_REG
|
|
p.To.Reg = REG_X10
|
|
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = ABLTU
|
|
p.From.Type = obj.TYPE_REG
|
|
p.From.Reg = REG_X10
|
|
p.Reg = REG_X11
|
|
p.To.Type = obj.TYPE_BRANCH
|
|
to_done = p
|
|
}
|
|
|
|
p = ctxt.EmitEntryLiveness(cursym, p, newprog)
|
|
|
|
// CALL runtime.morestack(SB)
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = obj.ACALL
|
|
p.To.Type = obj.TYPE_BRANCH
|
|
if cursym.CFunc() {
|
|
p.To.Sym = ctxt.Lookup("runtime.morestackc")
|
|
} else if !cursym.Func.Text.From.Sym.NeedCtxt() {
|
|
p.To.Sym = ctxt.Lookup("runtime.morestack_noctxt")
|
|
} else {
|
|
p.To.Sym = ctxt.Lookup("runtime.morestack")
|
|
}
|
|
if to_more != nil {
|
|
to_more.To.SetTarget(p)
|
|
}
|
|
p = jalrToSym(ctxt, p, newprog, REG_X5)
|
|
|
|
// JMP start
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = AJAL
|
|
p.To = obj.Addr{Type: obj.TYPE_BRANCH}
|
|
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
|
|
p.To.SetTarget(cursym.Func.Text.Link)
|
|
|
|
// placeholder for to_done's jump target
|
|
p = obj.Appendp(p, newprog)
|
|
p.As = obj.ANOP // zero-width place holder
|
|
to_done.To.SetTarget(p)
|
|
|
|
return p
|
|
}
|
|
|
|
// signExtend sign extends val starting at bit bit.
|
|
func signExtend(val int64, bit uint) int64 {
|
|
return val << (64 - bit) >> (64 - bit)
|
|
}
|
|
|
|
// Split32BitImmediate splits a signed 32-bit immediate into a signed 20-bit
|
|
// upper immediate and a signed 12-bit lower immediate to be added to the upper
|
|
// result. For example, high may be used in LUI and low in a following ADDI to
|
|
// generate a full 32-bit constant.
|
|
func Split32BitImmediate(imm int64) (low, high int64, err error) {
|
|
if !immIFits(imm, 32) {
|
|
return 0, 0, fmt.Errorf("immediate does not fit in 32-bits: %d", imm)
|
|
}
|
|
|
|
// Nothing special needs to be done if the immediate fits in 12-bits.
|
|
if immIFits(imm, 12) {
|
|
return imm, 0, nil
|
|
}
|
|
|
|
high = imm >> 12
|
|
|
|
// The bottom 12 bits will be treated as signed.
|
|
//
|
|
// If that will result in a negative 12 bit number, add 1 to
|
|
// our upper bits to adjust for the borrow.
|
|
//
|
|
// It is not possible for this increment to overflow. To
|
|
// overflow, the 20 top bits would be 1, and the sign bit for
|
|
// the low 12 bits would be set, in which case the entire 32
|
|
// bit pattern fits in a 12 bit signed value.
|
|
if imm&(1<<11) != 0 {
|
|
high++
|
|
}
|
|
|
|
low = signExtend(imm, 12)
|
|
high = signExtend(high, 20)
|
|
|
|
return low, high, nil
|
|
}
|
|
|
|
func regVal(r, min, max uint32) uint32 {
|
|
if r < min || r > max {
|
|
panic(fmt.Sprintf("register out of range, want %d < %d < %d", min, r, max))
|
|
}
|
|
return r - min
|
|
}
|
|
|
|
// regI returns an integer register.
|
|
func regI(r uint32) uint32 {
|
|
return regVal(r, REG_X0, REG_X31)
|
|
}
|
|
|
|
// regF returns a float register.
|
|
func regF(r uint32) uint32 {
|
|
return regVal(r, REG_F0, REG_F31)
|
|
}
|
|
|
|
// regAddr extracts a register from an Addr.
|
|
func regAddr(a obj.Addr, min, max uint32) uint32 {
|
|
if a.Type != obj.TYPE_REG {
|
|
panic(fmt.Sprintf("ill typed: %+v", a))
|
|
}
|
|
return regVal(uint32(a.Reg), min, max)
|
|
}
|
|
|
|
// regIAddr extracts the integer register from an Addr.
|
|
func regIAddr(a obj.Addr) uint32 {
|
|
return regAddr(a, REG_X0, REG_X31)
|
|
}
|
|
|
|
// regFAddr extracts the float register from an Addr.
|
|
func regFAddr(a obj.Addr) uint32 {
|
|
return regAddr(a, REG_F0, REG_F31)
|
|
}
|
|
|
|
// immIFits reports whether immediate value x fits in nbits bits
|
|
// as a signed integer.
|
|
func immIFits(x int64, nbits uint) bool {
|
|
nbits--
|
|
var min int64 = -1 << nbits
|
|
var max int64 = 1<<nbits - 1
|
|
return min <= x && x <= max
|
|
}
|
|
|
|
// immI extracts the signed integer of the specified size from an immediate.
|
|
func immI(as obj.As, imm int64, nbits uint) uint32 {
|
|
if !immIFits(imm, nbits) {
|
|
panic(fmt.Sprintf("%v\tsigned immediate %d cannot fit in %d bits", as, imm, nbits))
|
|
}
|
|
return uint32(imm)
|
|
}
|
|
|
|
func wantImmI(ctxt *obj.Link, as obj.As, imm int64, nbits uint) {
|
|
if !immIFits(imm, nbits) {
|
|
ctxt.Diag("%v\tsigned immediate cannot be larger than %d bits but got %d", as, nbits, imm)
|
|
}
|
|
}
|
|
|
|
func wantReg(ctxt *obj.Link, as obj.As, pos string, descr string, r, min, max uint32) {
|
|
if r < min || r > max {
|
|
var suffix string
|
|
if r != obj.REG_NONE {
|
|
suffix = fmt.Sprintf(" but got non-%s register %s", descr, RegName(int(r)))
|
|
}
|
|
ctxt.Diag("%v\texpected %s register in %s position%s", as, descr, pos, suffix)
|
|
}
|
|
}
|
|
|
|
func wantNoneReg(ctxt *obj.Link, as obj.As, pos string, r uint32) {
|
|
if r != obj.REG_NONE {
|
|
ctxt.Diag("%v\texpected no register in %s but got register %s", as, pos, RegName(int(r)))
|
|
}
|
|
}
|
|
|
|
// wantIntReg checks that r is an integer register.
|
|
func wantIntReg(ctxt *obj.Link, as obj.As, pos string, r uint32) {
|
|
wantReg(ctxt, as, pos, "integer", r, REG_X0, REG_X31)
|
|
}
|
|
|
|
// wantFloatReg checks that r is a floating-point register.
|
|
func wantFloatReg(ctxt *obj.Link, as obj.As, pos string, r uint32) {
|
|
wantReg(ctxt, as, pos, "float", r, REG_F0, REG_F31)
|
|
}
|
|
|
|
// wantEvenOffset checks that the offset is a multiple of two.
|
|
func wantEvenOffset(ctxt *obj.Link, as obj.As, offset int64) {
|
|
if offset%1 != 0 {
|
|
ctxt.Diag("%v\tjump offset %v must be even", as, offset)
|
|
}
|
|
}
|
|
|
|
func validateRIII(ctxt *obj.Link, ins *instruction) {
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantIntReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantIntReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRFFF(ctxt *obj.Link, ins *instruction) {
|
|
wantFloatReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantFloatReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantFloatReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRFFI(ctxt *obj.Link, ins *instruction) {
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantFloatReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantFloatReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRFI(ctxt *obj.Link, ins *instruction) {
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantNoneReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantFloatReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRIF(ctxt *obj.Link, ins *instruction) {
|
|
wantFloatReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantNoneReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantIntReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRFF(ctxt *obj.Link, ins *instruction) {
|
|
wantFloatReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantNoneReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantFloatReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateII(ctxt *obj.Link, ins *instruction) {
|
|
wantImmI(ctxt, ins.as, ins.imm, 12)
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantIntReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
}
|
|
|
|
func validateIF(ctxt *obj.Link, ins *instruction) {
|
|
wantImmI(ctxt, ins.as, ins.imm, 12)
|
|
wantFloatReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantIntReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
}
|
|
|
|
func validateSI(ctxt *obj.Link, ins *instruction) {
|
|
wantImmI(ctxt, ins.as, ins.imm, 12)
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantIntReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
}
|
|
|
|
func validateSF(ctxt *obj.Link, ins *instruction) {
|
|
wantImmI(ctxt, ins.as, ins.imm, 12)
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantFloatReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
}
|
|
|
|
func validateB(ctxt *obj.Link, ins *instruction) {
|
|
// Offsets are multiples of two, so accept 13 bit immediates for the
|
|
// 12 bit slot. We implicitly drop the least significant bit in encodeB.
|
|
wantEvenOffset(ctxt, ins.as, ins.imm)
|
|
wantImmI(ctxt, ins.as, ins.imm, 13)
|
|
wantNoneReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantIntReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantIntReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateU(ctxt *obj.Link, ins *instruction) {
|
|
wantImmI(ctxt, ins.as, ins.imm, 20)
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantNoneReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantNoneReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateJ(ctxt *obj.Link, ins *instruction) {
|
|
// Offsets are multiples of two, so accept 21 bit immediates for the
|
|
// 20 bit slot. We implicitly drop the least significant bit in encodeJ.
|
|
wantEvenOffset(ctxt, ins.as, ins.imm)
|
|
wantImmI(ctxt, ins.as, ins.imm, 21)
|
|
wantIntReg(ctxt, ins.as, "rd", ins.rd)
|
|
wantNoneReg(ctxt, ins.as, "rs1", ins.rs1)
|
|
wantNoneReg(ctxt, ins.as, "rs2", ins.rs2)
|
|
}
|
|
|
|
func validateRaw(ctxt *obj.Link, ins *instruction) {
|
|
// Treat the raw value specially as a 32-bit unsigned integer.
|
|
// Nobody wants to enter negative machine code.
|
|
if ins.imm < 0 || 1<<32 <= ins.imm {
|
|
ctxt.Diag("%v\timmediate in raw position cannot be larger than 32 bits but got %d", ins.as, ins.imm)
|
|
}
|
|
}
|
|
|
|
// encodeR encodes an R-type RISC-V instruction.
|
|
func encodeR(as obj.As, rs1, rs2, rd, funct3, funct7 uint32) uint32 {
|
|
enc := encode(as)
|
|
if enc == nil {
|
|
panic("encodeR: could not encode instruction")
|
|
}
|
|
if enc.rs2 != 0 && rs2 != 0 {
|
|
panic("encodeR: instruction uses rs2, but rs2 was nonzero")
|
|
}
|
|
return funct7<<25 | enc.funct7<<25 | enc.rs2<<20 | rs2<<20 | rs1<<15 | enc.funct3<<12 | funct3<<12 | rd<<7 | enc.opcode
|
|
}
|
|
|
|
func encodeRIII(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regI(ins.rs1), regI(ins.rs2), regI(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
func encodeRFFF(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regF(ins.rs1), regF(ins.rs2), regF(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
func encodeRFFI(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regF(ins.rs1), regF(ins.rs2), regI(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
func encodeRFI(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regF(ins.rs2), 0, regI(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
func encodeRIF(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regI(ins.rs2), 0, regF(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
func encodeRFF(ins *instruction) uint32 {
|
|
return encodeR(ins.as, regF(ins.rs2), 0, regF(ins.rd), ins.funct3, ins.funct7)
|
|
}
|
|
|
|
// encodeI encodes an I-type RISC-V instruction.
|
|
func encodeI(as obj.As, rs1, rd, imm uint32) uint32 {
|
|
enc := encode(as)
|
|
if enc == nil {
|
|
panic("encodeI: could not encode instruction")
|
|
}
|
|
imm |= uint32(enc.csr)
|
|
return imm<<20 | rs1<<15 | enc.funct3<<12 | rd<<7 | enc.opcode
|
|
}
|
|
|
|
func encodeII(ins *instruction) uint32 {
|
|
return encodeI(ins.as, regI(ins.rs1), regI(ins.rd), uint32(ins.imm))
|
|
}
|
|
|
|
func encodeIF(ins *instruction) uint32 {
|
|
return encodeI(ins.as, regI(ins.rs1), regF(ins.rd), uint32(ins.imm))
|
|
}
|
|
|
|
// encodeS encodes an S-type RISC-V instruction.
|
|
func encodeS(as obj.As, rs1, rs2, imm uint32) uint32 {
|
|
enc := encode(as)
|
|
if enc == nil {
|
|
panic("encodeS: could not encode instruction")
|
|
}
|
|
return (imm>>5)<<25 | rs2<<20 | rs1<<15 | enc.funct3<<12 | (imm&0x1f)<<7 | enc.opcode
|
|
}
|
|
|
|
func encodeSI(ins *instruction) uint32 {
|
|
return encodeS(ins.as, regI(ins.rd), regI(ins.rs1), uint32(ins.imm))
|
|
}
|
|
|
|
func encodeSF(ins *instruction) uint32 {
|
|
return encodeS(ins.as, regI(ins.rd), regF(ins.rs1), uint32(ins.imm))
|
|
}
|
|
|
|
// encodeB encodes a B-type RISC-V instruction.
|
|
func encodeB(ins *instruction) uint32 {
|
|
imm := immI(ins.as, ins.imm, 13)
|
|
rs2 := regI(ins.rs1)
|
|
rs1 := regI(ins.rs2)
|
|
enc := encode(ins.as)
|
|
if enc == nil {
|
|
panic("encodeB: could not encode instruction")
|
|
}
|
|
return (imm>>12)<<31 | ((imm>>5)&0x3f)<<25 | rs2<<20 | rs1<<15 | enc.funct3<<12 | ((imm>>1)&0xf)<<8 | ((imm>>11)&0x1)<<7 | enc.opcode
|
|
}
|
|
|
|
// encodeU encodes a U-type RISC-V instruction.
|
|
func encodeU(ins *instruction) uint32 {
|
|
// The immediates for encodeU are the upper 20 bits of a 32 bit value.
|
|
// Rather than have the user/compiler generate a 32 bit constant, the
|
|
// bottommost bits of which must all be zero, instead accept just the
|
|
// top bits.
|
|
imm := immI(ins.as, ins.imm, 20)
|
|
rd := regI(ins.rd)
|
|
enc := encode(ins.as)
|
|
if enc == nil {
|
|
panic("encodeU: could not encode instruction")
|
|
}
|
|
return imm<<12 | rd<<7 | enc.opcode
|
|
}
|
|
|
|
// encodeJ encodes a J-type RISC-V instruction.
|
|
func encodeJ(ins *instruction) uint32 {
|
|
imm := immI(ins.as, ins.imm, 21)
|
|
rd := regI(ins.rd)
|
|
enc := encode(ins.as)
|
|
if enc == nil {
|
|
panic("encodeJ: could not encode instruction")
|
|
}
|
|
return (imm>>20)<<31 | ((imm>>1)&0x3ff)<<21 | ((imm>>11)&0x1)<<20 | ((imm>>12)&0xff)<<12 | rd<<7 | enc.opcode
|
|
}
|
|
|
|
func encodeRawIns(ins *instruction) uint32 {
|
|
// Treat the raw value specially as a 32-bit unsigned integer.
|
|
// Nobody wants to enter negative machine code.
|
|
if ins.imm < 0 || 1<<32 <= ins.imm {
|
|
panic(fmt.Sprintf("immediate %d cannot fit in 32 bits", ins.imm))
|
|
}
|
|
return uint32(ins.imm)
|
|
}
|
|
|
|
func EncodeIImmediate(imm int64) (int64, error) {
|
|
if !immIFits(imm, 12) {
|
|
return 0, fmt.Errorf("immediate %#x does not fit in 12 bits", imm)
|
|
}
|
|
return imm << 20, nil
|
|
}
|
|
|
|
func EncodeSImmediate(imm int64) (int64, error) {
|
|
if !immIFits(imm, 12) {
|
|
return 0, fmt.Errorf("immediate %#x does not fit in 12 bits", imm)
|
|
}
|
|
return ((imm >> 5) << 25) | ((imm & 0x1f) << 7), nil
|
|
}
|
|
|
|
func EncodeUImmediate(imm int64) (int64, error) {
|
|
if !immIFits(imm, 20) {
|
|
return 0, fmt.Errorf("immediate %#x does not fit in 20 bits", imm)
|
|
}
|
|
return imm << 12, nil
|
|
}
|
|
|
|
type encoding struct {
|
|
encode func(*instruction) uint32 // encode returns the machine code for an instruction
|
|
validate func(*obj.Link, *instruction) // validate validates an instruction
|
|
length int // length of encoded instruction; 0 for pseudo-ops, 4 otherwise
|
|
}
|
|
|
|
var (
|
|
// Encodings have the following naming convention:
|
|
//
|
|
// 1. the instruction encoding (R/I/S/B/U/J), in lowercase
|
|
// 2. zero or more register operand identifiers (I = integer
|
|
// register, F = float register), in uppercase
|
|
// 3. the word "Encoding"
|
|
//
|
|
// For example, rIIIEncoding indicates an R-type instruction with two
|
|
// integer register inputs and an integer register output; sFEncoding
|
|
// indicates an S-type instruction with rs2 being a float register.
|
|
|
|
rIIIEncoding = encoding{encode: encodeRIII, validate: validateRIII, length: 4}
|
|
rFFFEncoding = encoding{encode: encodeRFFF, validate: validateRFFF, length: 4}
|
|
rFFIEncoding = encoding{encode: encodeRFFI, validate: validateRFFI, length: 4}
|
|
rFIEncoding = encoding{encode: encodeRFI, validate: validateRFI, length: 4}
|
|
rIFEncoding = encoding{encode: encodeRIF, validate: validateRIF, length: 4}
|
|
rFFEncoding = encoding{encode: encodeRFF, validate: validateRFF, length: 4}
|
|
|
|
iIEncoding = encoding{encode: encodeII, validate: validateII, length: 4}
|
|
iFEncoding = encoding{encode: encodeIF, validate: validateIF, length: 4}
|
|
|
|
sIEncoding = encoding{encode: encodeSI, validate: validateSI, length: 4}
|
|
sFEncoding = encoding{encode: encodeSF, validate: validateSF, length: 4}
|
|
|
|
bEncoding = encoding{encode: encodeB, validate: validateB, length: 4}
|
|
uEncoding = encoding{encode: encodeU, validate: validateU, length: 4}
|
|
jEncoding = encoding{encode: encodeJ, validate: validateJ, length: 4}
|
|
|
|
// rawEncoding encodes a raw instruction byte sequence.
|
|
rawEncoding = encoding{encode: encodeRawIns, validate: validateRaw, length: 4}
|
|
|
|
// pseudoOpEncoding panics if encoding is attempted, but does no validation.
|
|
pseudoOpEncoding = encoding{encode: nil, validate: func(*obj.Link, *instruction) {}, length: 0}
|
|
|
|
// badEncoding is used when an invalid op is encountered.
|
|
// An error has already been generated, so let anything else through.
|
|
badEncoding = encoding{encode: func(*instruction) uint32 { return 0 }, validate: func(*obj.Link, *instruction) {}, length: 0}
|
|
)
|
|
|
|
// encodings contains the encodings for RISC-V instructions.
|
|
// Instructions are masked with obj.AMask to keep indices small.
|
|
var encodings = [ALAST & obj.AMask]encoding{
|
|
|
|
// Unprivileged ISA
|
|
|
|
// 2.4: Integer Computational Instructions
|
|
AADDI & obj.AMask: iIEncoding,
|
|
ASLTI & obj.AMask: iIEncoding,
|
|
ASLTIU & obj.AMask: iIEncoding,
|
|
AANDI & obj.AMask: iIEncoding,
|
|
AORI & obj.AMask: iIEncoding,
|
|
AXORI & obj.AMask: iIEncoding,
|
|
ASLLI & obj.AMask: iIEncoding,
|
|
ASRLI & obj.AMask: iIEncoding,
|
|
ASRAI & obj.AMask: iIEncoding,
|
|
ALUI & obj.AMask: uEncoding,
|
|
AAUIPC & obj.AMask: uEncoding,
|
|
AADD & obj.AMask: rIIIEncoding,
|
|
ASLT & obj.AMask: rIIIEncoding,
|
|
ASLTU & obj.AMask: rIIIEncoding,
|
|
AAND & obj.AMask: rIIIEncoding,
|
|
AOR & obj.AMask: rIIIEncoding,
|
|
AXOR & obj.AMask: rIIIEncoding,
|
|
ASLL & obj.AMask: rIIIEncoding,
|
|
ASRL & obj.AMask: rIIIEncoding,
|
|
ASUB & obj.AMask: rIIIEncoding,
|
|
ASRA & obj.AMask: rIIIEncoding,
|
|
|
|
// 2.5: Control Transfer Instructions
|
|
AJAL & obj.AMask: jEncoding,
|
|
AJALR & obj.AMask: iIEncoding,
|
|
ABEQ & obj.AMask: bEncoding,
|
|
ABNE & obj.AMask: bEncoding,
|
|
ABLT & obj.AMask: bEncoding,
|
|
ABLTU & obj.AMask: bEncoding,
|
|
ABGE & obj.AMask: bEncoding,
|
|
ABGEU & obj.AMask: bEncoding,
|
|
|
|
// 2.6: Load and Store Instructions
|
|
ALW & obj.AMask: iIEncoding,
|
|
ALWU & obj.AMask: iIEncoding,
|
|
ALH & obj.AMask: iIEncoding,
|
|
ALHU & obj.AMask: iIEncoding,
|
|
ALB & obj.AMask: iIEncoding,
|
|
ALBU & obj.AMask: iIEncoding,
|
|
ASW & obj.AMask: sIEncoding,
|
|
ASH & obj.AMask: sIEncoding,
|
|
ASB & obj.AMask: sIEncoding,
|
|
|
|
// 2.7: Memory Ordering
|
|
AFENCE & obj.AMask: iIEncoding,
|
|
|
|
// 5.2: Integer Computational Instructions (RV64I)
|
|
AADDIW & obj.AMask: iIEncoding,
|
|
ASLLIW & obj.AMask: iIEncoding,
|
|
ASRLIW & obj.AMask: iIEncoding,
|
|
ASRAIW & obj.AMask: iIEncoding,
|
|
AADDW & obj.AMask: rIIIEncoding,
|
|
ASLLW & obj.AMask: rIIIEncoding,
|
|
ASRLW & obj.AMask: rIIIEncoding,
|
|
ASUBW & obj.AMask: rIIIEncoding,
|
|
ASRAW & obj.AMask: rIIIEncoding,
|
|
|
|
// 5.3: Load and Store Instructions (RV64I)
|
|
ALD & obj.AMask: iIEncoding,
|
|
ASD & obj.AMask: sIEncoding,
|
|
|
|
// 7.1: Multiplication Operations
|
|
AMUL & obj.AMask: rIIIEncoding,
|
|
AMULH & obj.AMask: rIIIEncoding,
|
|
AMULHU & obj.AMask: rIIIEncoding,
|
|
AMULHSU & obj.AMask: rIIIEncoding,
|
|
AMULW & obj.AMask: rIIIEncoding,
|
|
ADIV & obj.AMask: rIIIEncoding,
|
|
ADIVU & obj.AMask: rIIIEncoding,
|
|
AREM & obj.AMask: rIIIEncoding,
|
|
AREMU & obj.AMask: rIIIEncoding,
|
|
ADIVW & obj.AMask: rIIIEncoding,
|
|
ADIVUW & obj.AMask: rIIIEncoding,
|
|
AREMW & obj.AMask: rIIIEncoding,
|
|
AREMUW & obj.AMask: rIIIEncoding,
|
|
|
|
// 8.2: Load-Reserved/Store-Conditional
|
|
ALRW & obj.AMask: rIIIEncoding,
|
|
ALRD & obj.AMask: rIIIEncoding,
|
|
ASCW & obj.AMask: rIIIEncoding,
|
|
ASCD & obj.AMask: rIIIEncoding,
|
|
|
|
// 8.3: Atomic Memory Operations
|
|
AAMOSWAPW & obj.AMask: rIIIEncoding,
|
|
AAMOSWAPD & obj.AMask: rIIIEncoding,
|
|
AAMOADDW & obj.AMask: rIIIEncoding,
|
|
AAMOADDD & obj.AMask: rIIIEncoding,
|
|
AAMOANDW & obj.AMask: rIIIEncoding,
|
|
AAMOANDD & obj.AMask: rIIIEncoding,
|
|
AAMOORW & obj.AMask: rIIIEncoding,
|
|
AAMOORD & obj.AMask: rIIIEncoding,
|
|
AAMOXORW & obj.AMask: rIIIEncoding,
|
|
AAMOXORD & obj.AMask: rIIIEncoding,
|
|
AAMOMAXW & obj.AMask: rIIIEncoding,
|
|
AAMOMAXD & obj.AMask: rIIIEncoding,
|
|
AAMOMAXUW & obj.AMask: rIIIEncoding,
|
|
AAMOMAXUD & obj.AMask: rIIIEncoding,
|
|
AAMOMINW & obj.AMask: rIIIEncoding,
|
|
AAMOMIND & obj.AMask: rIIIEncoding,
|
|
AAMOMINUW & obj.AMask: rIIIEncoding,
|
|
AAMOMINUD & obj.AMask: rIIIEncoding,
|
|
|
|
// 10.1: Base Counters and Timers
|
|
ARDCYCLE & obj.AMask: iIEncoding,
|
|
ARDTIME & obj.AMask: iIEncoding,
|
|
ARDINSTRET & obj.AMask: iIEncoding,
|
|
|
|
// 11.5: Single-Precision Load and Store Instructions
|
|
AFLW & obj.AMask: iFEncoding,
|
|
AFSW & obj.AMask: sFEncoding,
|
|
|
|
// 11.6: Single-Precision Floating-Point Computational Instructions
|
|
AFADDS & obj.AMask: rFFFEncoding,
|
|
AFSUBS & obj.AMask: rFFFEncoding,
|
|
AFMULS & obj.AMask: rFFFEncoding,
|
|
AFDIVS & obj.AMask: rFFFEncoding,
|
|
AFMINS & obj.AMask: rFFFEncoding,
|
|
AFMAXS & obj.AMask: rFFFEncoding,
|
|
AFSQRTS & obj.AMask: rFFFEncoding,
|
|
|
|
// 11.7: Single-Precision Floating-Point Conversion and Move Instructions
|
|
AFCVTWS & obj.AMask: rFIEncoding,
|
|
AFCVTLS & obj.AMask: rFIEncoding,
|
|
AFCVTSW & obj.AMask: rIFEncoding,
|
|
AFCVTSL & obj.AMask: rIFEncoding,
|
|
AFCVTWUS & obj.AMask: rFIEncoding,
|
|
AFCVTLUS & obj.AMask: rFIEncoding,
|
|
AFCVTSWU & obj.AMask: rIFEncoding,
|
|
AFCVTSLU & obj.AMask: rIFEncoding,
|
|
AFSGNJS & obj.AMask: rFFFEncoding,
|
|
AFSGNJNS & obj.AMask: rFFFEncoding,
|
|
AFSGNJXS & obj.AMask: rFFFEncoding,
|
|
AFMVXS & obj.AMask: rFIEncoding,
|
|
AFMVSX & obj.AMask: rIFEncoding,
|
|
AFMVXW & obj.AMask: rFIEncoding,
|
|
AFMVWX & obj.AMask: rIFEncoding,
|
|
|
|
// 11.8: Single-Precision Floating-Point Compare Instructions
|
|
AFEQS & obj.AMask: rFFIEncoding,
|
|
AFLTS & obj.AMask: rFFIEncoding,
|
|
AFLES & obj.AMask: rFFIEncoding,
|
|
|
|
// 11.9: Single-Precision Floating-Point Classify Instruction
|
|
AFCLASSS & obj.AMask: rFIEncoding,
|
|
|
|
// 12.3: Double-Precision Load and Store Instructions
|
|
AFLD & obj.AMask: iFEncoding,
|
|
AFSD & obj.AMask: sFEncoding,
|
|
|
|
// 12.4: Double-Precision Floating-Point Computational Instructions
|
|
AFADDD & obj.AMask: rFFFEncoding,
|
|
AFSUBD & obj.AMask: rFFFEncoding,
|
|
AFMULD & obj.AMask: rFFFEncoding,
|
|
AFDIVD & obj.AMask: rFFFEncoding,
|
|
AFMIND & obj.AMask: rFFFEncoding,
|
|
AFMAXD & obj.AMask: rFFFEncoding,
|
|
AFSQRTD & obj.AMask: rFFFEncoding,
|
|
|
|
// 12.5: Double-Precision Floating-Point Conversion and Move Instructions
|
|
AFCVTWD & obj.AMask: rFIEncoding,
|
|
AFCVTLD & obj.AMask: rFIEncoding,
|
|
AFCVTDW & obj.AMask: rIFEncoding,
|
|
AFCVTDL & obj.AMask: rIFEncoding,
|
|
AFCVTWUD & obj.AMask: rFIEncoding,
|
|
AFCVTLUD & obj.AMask: rFIEncoding,
|
|
AFCVTDWU & obj.AMask: rIFEncoding,
|
|
AFCVTDLU & obj.AMask: rIFEncoding,
|
|
AFCVTSD & obj.AMask: rFFEncoding,
|
|
AFCVTDS & obj.AMask: rFFEncoding,
|
|
AFSGNJD & obj.AMask: rFFFEncoding,
|
|
AFSGNJND & obj.AMask: rFFFEncoding,
|
|
AFSGNJXD & obj.AMask: rFFFEncoding,
|
|
AFMVXD & obj.AMask: rFIEncoding,
|
|
AFMVDX & obj.AMask: rIFEncoding,
|
|
|
|
// 12.6: Double-Precision Floating-Point Compare Instructions
|
|
AFEQD & obj.AMask: rFFIEncoding,
|
|
AFLTD & obj.AMask: rFFIEncoding,
|
|
AFLED & obj.AMask: rFFIEncoding,
|
|
|
|
// 12.7: Double-Precision Floating-Point Classify Instruction
|
|
AFCLASSD & obj.AMask: rFIEncoding,
|
|
|
|
// Privileged ISA
|
|
|
|
// 3.2.1: Environment Call and Breakpoint
|
|
AECALL & obj.AMask: iIEncoding,
|
|
AEBREAK & obj.AMask: iIEncoding,
|
|
|
|
// Escape hatch
|
|
AWORD & obj.AMask: rawEncoding,
|
|
|
|
// Pseudo-operations
|
|
obj.AFUNCDATA: pseudoOpEncoding,
|
|
obj.APCDATA: pseudoOpEncoding,
|
|
obj.ATEXT: pseudoOpEncoding,
|
|
obj.ANOP: pseudoOpEncoding,
|
|
}
|
|
|
|
// encodingForAs returns the encoding for an obj.As.
|
|
func encodingForAs(as obj.As) (encoding, error) {
|
|
if base := as &^ obj.AMask; base != obj.ABaseRISCV && base != 0 {
|
|
return badEncoding, fmt.Errorf("encodingForAs: not a RISC-V instruction %s", as)
|
|
}
|
|
asi := as & obj.AMask
|
|
if int(asi) >= len(encodings) {
|
|
return badEncoding, fmt.Errorf("encodingForAs: bad RISC-V instruction %s", as)
|
|
}
|
|
enc := encodings[asi]
|
|
if enc.validate == nil {
|
|
return badEncoding, fmt.Errorf("encodingForAs: no encoding for instruction %s", as)
|
|
}
|
|
return enc, nil
|
|
}
|
|
|
|
type instruction struct {
|
|
as obj.As // Assembler opcode
|
|
rd uint32 // Destination register
|
|
rs1 uint32 // Source register 1
|
|
rs2 uint32 // Source register 2
|
|
imm int64 // Immediate
|
|
funct3 uint32 // Function 3
|
|
funct7 uint32 // Function 7
|
|
}
|
|
|
|
func (ins *instruction) encode() (uint32, error) {
|
|
enc, err := encodingForAs(ins.as)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if enc.length > 0 {
|
|
return enc.encode(ins), nil
|
|
}
|
|
return 0, fmt.Errorf("fixme")
|
|
}
|
|
|
|
func (ins *instruction) length() int {
|
|
enc, err := encodingForAs(ins.as)
|
|
if err != nil {
|
|
return 0
|
|
}
|
|
return enc.length
|
|
}
|
|
|
|
func (ins *instruction) validate(ctxt *obj.Link) {
|
|
enc, err := encodingForAs(ins.as)
|
|
if err != nil {
|
|
ctxt.Diag(err.Error())
|
|
return
|
|
}
|
|
enc.validate(ctxt, ins)
|
|
}
|
|
|
|
// instructionsForProg returns the machine instructions for an *obj.Prog.
|
|
func instructionsForProg(p *obj.Prog) []*instruction {
|
|
ins := &instruction{
|
|
as: p.As,
|
|
rd: uint32(p.To.Reg),
|
|
rs1: uint32(p.Reg),
|
|
rs2: uint32(p.From.Reg),
|
|
imm: p.From.Offset,
|
|
}
|
|
|
|
inss := []*instruction{ins}
|
|
switch ins.as {
|
|
case AJAL, AJALR:
|
|
ins.rd, ins.rs1, ins.rs2 = uint32(p.From.Reg), uint32(p.To.Reg), obj.REG_NONE
|
|
ins.imm = p.To.Offset
|
|
|
|
case ABEQ, ABEQZ, ABGE, ABGEU, ABGEZ, ABGT, ABGTU, ABGTZ, ABLE, ABLEU, ABLEZ, ABLT, ABLTU, ABLTZ, ABNE, ABNEZ:
|
|
switch ins.as {
|
|
case ABEQZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABEQ, REG_ZERO, uint32(p.From.Reg)
|
|
case ABGEZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABGE, REG_ZERO, uint32(p.From.Reg)
|
|
case ABGT:
|
|
ins.as, ins.rs1, ins.rs2 = ABLT, uint32(p.Reg), uint32(p.From.Reg)
|
|
case ABGTU:
|
|
ins.as, ins.rs1, ins.rs2 = ABLTU, uint32(p.Reg), uint32(p.From.Reg)
|
|
case ABGTZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABLT, uint32(p.From.Reg), REG_ZERO
|
|
case ABLE:
|
|
ins.as, ins.rs1, ins.rs2 = ABGE, uint32(p.Reg), uint32(p.From.Reg)
|
|
case ABLEU:
|
|
ins.as, ins.rs1, ins.rs2 = ABGEU, uint32(p.Reg), uint32(p.From.Reg)
|
|
case ABLEZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABGE, uint32(p.From.Reg), REG_ZERO
|
|
case ABLTZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABLT, REG_ZERO, uint32(p.From.Reg)
|
|
case ABNEZ:
|
|
ins.as, ins.rs1, ins.rs2 = ABNE, REG_ZERO, uint32(p.From.Reg)
|
|
}
|
|
ins.imm = p.To.Offset
|
|
|
|
case ALW, ALWU, ALH, ALHU, ALB, ALBU, ALD, AFLW, AFLD:
|
|
if p.From.Type != obj.TYPE_MEM {
|
|
p.Ctxt.Diag("%v requires memory for source", p)
|
|
return nil
|
|
}
|
|
ins.rs1, ins.rs2 = uint32(p.From.Reg), obj.REG_NONE
|
|
ins.imm = p.From.Offset
|
|
|
|
case ASW, ASH, ASB, ASD, AFSW, AFSD:
|
|
if p.To.Type != obj.TYPE_MEM {
|
|
p.Ctxt.Diag("%v requires memory for destination", p)
|
|
return nil
|
|
}
|
|
ins.rs1, ins.rs2 = uint32(p.From.Reg), obj.REG_NONE
|
|
ins.imm = p.To.Offset
|
|
|
|
case ALRW, ALRD:
|
|
// Set aq to use acquire access ordering, which matches Go's memory requirements.
|
|
ins.funct7 = 2
|
|
ins.rs1, ins.rs2 = uint32(p.From.Reg), REG_ZERO
|
|
|
|
case ASCW, ASCD, AAMOSWAPW, AAMOSWAPD, AAMOADDW, AAMOADDD, AAMOANDW, AAMOANDD, AAMOORW, AAMOORD,
|
|
AAMOXORW, AAMOXORD, AAMOMINW, AAMOMIND, AAMOMINUW, AAMOMINUD, AAMOMAXW, AAMOMAXD, AAMOMAXUW, AAMOMAXUD:
|
|
// Set aq to use acquire access ordering, which matches Go's memory requirements.
|
|
ins.funct7 = 2
|
|
ins.rd, ins.rs1, ins.rs2 = uint32(p.RegTo2), uint32(p.To.Reg), uint32(p.From.Reg)
|
|
|
|
case AECALL, AEBREAK, ARDCYCLE, ARDTIME, ARDINSTRET:
|
|
insEnc := encode(p.As)
|
|
if p.To.Type == obj.TYPE_NONE {
|
|
ins.rd = REG_ZERO
|
|
}
|
|
ins.rs1 = REG_ZERO
|
|
ins.imm = insEnc.csr
|
|
|
|
case AFENCE:
|
|
ins.rd, ins.rs1, ins.rs2 = REG_ZERO, REG_ZERO, obj.REG_NONE
|
|
ins.imm = 0x0ff
|
|
|
|
case AFCVTWS, AFCVTLS, AFCVTWUS, AFCVTLUS, AFCVTWD, AFCVTLD, AFCVTWUD, AFCVTLUD:
|
|
// Set the rounding mode in funct3 to round to zero.
|
|
ins.funct3 = 1
|
|
|
|
case AFNES, AFNED:
|
|
// Replace FNE[SD] with FEQ[SD] and NOT.
|
|
if p.To.Type != obj.TYPE_REG {
|
|
p.Ctxt.Diag("%v needs an integer register output", ins.as)
|
|
return nil
|
|
}
|
|
if ins.as == AFNES {
|
|
ins.as = AFEQS
|
|
} else {
|
|
ins.as = AFEQD
|
|
}
|
|
ins = &instruction{
|
|
as: AXORI, // [bit] xor 1 = not [bit]
|
|
rd: ins.rd,
|
|
rs1: ins.rd,
|
|
imm: 1,
|
|
}
|
|
inss = append(inss, ins)
|
|
|
|
case AFSQRTS, AFSQRTD:
|
|
// These instructions expect a zero (i.e. float register 0)
|
|
// to be the second input operand.
|
|
ins.rs1 = uint32(p.From.Reg)
|
|
ins.rs2 = REG_F0
|
|
|
|
case ANEG, ANEGW:
|
|
// NEG rs, rd -> SUB rs, X0, rd
|
|
ins.as = ASUB
|
|
if p.As == ANEGW {
|
|
ins.as = ASUBW
|
|
}
|
|
ins.rs1 = REG_ZERO
|
|
if ins.rd == obj.REG_NONE {
|
|
ins.rd = ins.rs2
|
|
}
|
|
|
|
case ANOT:
|
|
// NOT rs, rd -> XORI $-1, rs, rd
|
|
ins.as = AXORI
|
|
ins.rs1, ins.rs2 = uint32(p.From.Reg), obj.REG_NONE
|
|
if ins.rd == obj.REG_NONE {
|
|
ins.rd = ins.rs1
|
|
}
|
|
ins.imm = -1
|
|
|
|
case ASEQZ:
|
|
// SEQZ rs, rd -> SLTIU $1, rs, rd
|
|
ins.as = ASLTIU
|
|
ins.rs1 = uint32(p.From.Reg)
|
|
ins.imm = 1
|
|
|
|
case ASNEZ:
|
|
// SNEZ rs, rd -> SLTU rs, x0, rd
|
|
ins.as = ASLTU
|
|
ins.rs1 = REG_ZERO
|
|
|
|
case AFNEGS:
|
|
// FNEGS rs, rd -> FSGNJNS rs, rs, rd
|
|
ins.as = AFSGNJNS
|
|
ins.rs1 = uint32(p.From.Reg)
|
|
|
|
case AFNEGD:
|
|
// FNEGD rs, rd -> FSGNJND rs, rs, rd
|
|
ins.as = AFSGNJND
|
|
ins.rs1 = uint32(p.From.Reg)
|
|
}
|
|
return inss
|
|
}
|
|
|
|
// assemble emits machine code.
|
|
// It is called at the very end of the assembly process.
|
|
func assemble(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
|
|
if ctxt.Retpoline {
|
|
ctxt.Diag("-spectre=ret not supported on riscv")
|
|
ctxt.Retpoline = false // don't keep printing
|
|
}
|
|
|
|
var symcode []uint32
|
|
for p := cursym.Func.Text; p != nil; p = p.Link {
|
|
switch p.As {
|
|
case AJALR:
|
|
if p.To.Sym != nil {
|
|
// This is a CALL/JMP. We add a relocation only
|
|
// for linker stack checking. No actual
|
|
// relocation is needed.
|
|
rel := obj.Addrel(cursym)
|
|
rel.Off = int32(p.Pc)
|
|
rel.Siz = 4
|
|
rel.Sym = p.To.Sym
|
|
rel.Add = p.To.Offset
|
|
rel.Type = objabi.R_CALLRISCV
|
|
}
|
|
case AAUIPC:
|
|
var rt objabi.RelocType
|
|
if p.Mark&NEED_PCREL_ITYPE_RELOC == NEED_PCREL_ITYPE_RELOC {
|
|
rt = objabi.R_RISCV_PCREL_ITYPE
|
|
} else if p.Mark&NEED_PCREL_STYPE_RELOC == NEED_PCREL_STYPE_RELOC {
|
|
rt = objabi.R_RISCV_PCREL_STYPE
|
|
} else {
|
|
break
|
|
}
|
|
if p.Link == nil {
|
|
ctxt.Diag("AUIPC needing PC-relative reloc missing following instruction")
|
|
break
|
|
}
|
|
addr := p.RestArgs[0]
|
|
if addr.Sym == nil {
|
|
ctxt.Diag("AUIPC needing PC-relative reloc missing symbol")
|
|
break
|
|
}
|
|
|
|
rel := obj.Addrel(cursym)
|
|
rel.Off = int32(p.Pc)
|
|
rel.Siz = 8
|
|
rel.Sym = addr.Sym
|
|
rel.Add = addr.Offset
|
|
rel.Type = rt
|
|
}
|
|
|
|
for _, ins := range instructionsForProg(p) {
|
|
ic, err := ins.encode()
|
|
if err == nil {
|
|
symcode = append(symcode, ic)
|
|
}
|
|
}
|
|
}
|
|
cursym.Size = int64(4 * len(symcode))
|
|
|
|
cursym.Grow(cursym.Size)
|
|
for p, i := cursym.P, 0; i < len(symcode); p, i = p[4:], i+1 {
|
|
ctxt.Arch.ByteOrder.PutUint32(p, symcode[i])
|
|
}
|
|
|
|
obj.MarkUnsafePoints(ctxt, cursym.Func.Text, newprog, isUnsafePoint, nil)
|
|
}
|
|
|
|
func isUnsafePoint(p *obj.Prog) bool {
|
|
return p.From.Reg == REG_TMP || p.To.Reg == REG_TMP || p.Reg == REG_TMP
|
|
}
|
|
|
|
var LinkRISCV64 = obj.LinkArch{
|
|
Arch: sys.ArchRISCV64,
|
|
Init: buildop,
|
|
Preprocess: preprocess,
|
|
Assemble: assemble,
|
|
Progedit: progedit,
|
|
UnaryDst: unaryDst,
|
|
DWARFRegisters: RISCV64DWARFRegisters,
|
|
}
|