[chore] Update gin to v1.9.0 (#1553)

vendor/github.com/twitchyliquid64/golang-asm/asm/arch/arm.go

@@ -0,0 +1,257 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file encapsulates some of the odd characteristics of the ARM
+// instruction set, to minimize its interaction with the core of the
+// assembler.
+
+package arch
+
+import (
+	"strings"
+
+	"github.com/twitchyliquid64/golang-asm/obj"
+	"github.com/twitchyliquid64/golang-asm/obj/arm"
+)
+
+var armLS = map[string]uint8{
+	"U":  arm.C_UBIT,
+	"S":  arm.C_SBIT,
+	"W":  arm.C_WBIT,
+	"P":  arm.C_PBIT,
+	"PW": arm.C_WBIT | arm.C_PBIT,
+	"WP": arm.C_WBIT | arm.C_PBIT,
+}
+
+var armSCOND = map[string]uint8{
+	"EQ":  arm.C_SCOND_EQ,
+	"NE":  arm.C_SCOND_NE,
+	"CS":  arm.C_SCOND_HS,
+	"HS":  arm.C_SCOND_HS,
+	"CC":  arm.C_SCOND_LO,
+	"LO":  arm.C_SCOND_LO,
+	"MI":  arm.C_SCOND_MI,
+	"PL":  arm.C_SCOND_PL,
+	"VS":  arm.C_SCOND_VS,
+	"VC":  arm.C_SCOND_VC,
+	"HI":  arm.C_SCOND_HI,
+	"LS":  arm.C_SCOND_LS,
+	"GE":  arm.C_SCOND_GE,
+	"LT":  arm.C_SCOND_LT,
+	"GT":  arm.C_SCOND_GT,
+	"LE":  arm.C_SCOND_LE,
+	"AL":  arm.C_SCOND_NONE,
+	"U":   arm.C_UBIT,
+	"S":   arm.C_SBIT,
+	"W":   arm.C_WBIT,
+	"P":   arm.C_PBIT,
+	"PW":  arm.C_WBIT | arm.C_PBIT,
+	"WP":  arm.C_WBIT | arm.C_PBIT,
+	"F":   arm.C_FBIT,
+	"IBW": arm.C_WBIT | arm.C_PBIT | arm.C_UBIT,
+	"IAW": arm.C_WBIT | arm.C_UBIT,
+	"DBW": arm.C_WBIT | arm.C_PBIT,
+	"DAW": arm.C_WBIT,
+	"IB":  arm.C_PBIT | arm.C_UBIT,
+	"IA":  arm.C_UBIT,
+	"DB":  arm.C_PBIT,
+	"DA":  0,
+}
+
+var armJump = map[string]bool{
+	"B":    true,
+	"BL":   true,
+	"BX":   true,
+	"BEQ":  true,
+	"BNE":  true,
+	"BCS":  true,
+	"BHS":  true,
+	"BCC":  true,
+	"BLO":  true,
+	"BMI":  true,
+	"BPL":  true,
+	"BVS":  true,
+	"BVC":  true,
+	"BHI":  true,
+	"BLS":  true,
+	"BGE":  true,
+	"BLT":  true,
+	"BGT":  true,
+	"BLE":  true,
+	"CALL": true,
+	"JMP":  true,
+}
+
+func jumpArm(word string) bool {
+	return armJump[word]
+}
+
+// IsARMCMP reports whether the op (as defined by an arm.A* constant) is
+// one of the comparison instructions that require special handling.
+func IsARMCMP(op obj.As) bool {
+	switch op {
+	case arm.ACMN, arm.ACMP, arm.ATEQ, arm.ATST:
+		return true
+	}
+	return false
+}
+
+// IsARMSTREX reports whether the op (as defined by an arm.A* constant) is
+// one of the STREX-like instructions that require special handling.
+func IsARMSTREX(op obj.As) bool {
+	switch op {
+	case arm.ASTREX, arm.ASTREXD, arm.ASWPW, arm.ASWPBU:
+		return true
+	}
+	return false
+}
+
+// MCR is not defined by the obj/arm; instead we define it privately here.
+// It is encoded as an MRC with a bit inside the instruction word,
+// passed to arch.ARMMRCOffset.
+const aMCR = arm.ALAST + 1
+
+// IsARMMRC reports whether the op (as defined by an arm.A* constant) is
+// MRC or MCR
+func IsARMMRC(op obj.As) bool {
+	switch op {
+	case arm.AMRC, aMCR: // Note: aMCR is defined in this package.
+		return true
+	}
+	return false
+}
+
+// IsARMBFX reports whether the op (as defined by an arm.A* constant) is one the
+// BFX-like instructions which are in the form of "op $width, $LSB, (Reg,) Reg".
+func IsARMBFX(op obj.As) bool {
+	switch op {
+	case arm.ABFX, arm.ABFXU, arm.ABFC, arm.ABFI:
+		return true
+	}
+	return false
+}
+
+// IsARMFloatCmp reports whether the op is a floating comparison instruction.
+func IsARMFloatCmp(op obj.As) bool {
+	switch op {
+	case arm.ACMPF, arm.ACMPD:
+		return true
+	}
+	return false
+}
+
+// ARMMRCOffset implements the peculiar encoding of the MRC and MCR instructions.
+// The difference between MRC and MCR is represented by a bit high in the word, not
+// in the usual way by the opcode itself. Asm must use AMRC for both instructions, so
+// we return the opcode for MRC so that asm doesn't need to import obj/arm.
+func ARMMRCOffset(op obj.As, cond string, x0, x1, x2, x3, x4, x5 int64) (offset int64, op0 obj.As, ok bool) {
+	op1 := int64(0)
+	if op == arm.AMRC {
+		op1 = 1
+	}
+	bits, ok := ParseARMCondition(cond)
+	if !ok {
+		return
+	}
+	offset = (0xe << 24) | // opcode
+		(op1 << 20) | // MCR/MRC
+		((int64(bits) ^ arm.C_SCOND_XOR) << 28) | // scond
+		((x0 & 15) << 8) | //coprocessor number
+		((x1 & 7) << 21) | // coprocessor operation
+		((x2 & 15) << 12) | // ARM register
+		((x3 & 15) << 16) | // Crn
+		((x4 & 15) << 0) | // Crm
+		((x5 & 7) << 5) | // coprocessor information
+		(1 << 4) /* must be set */
+	return offset, arm.AMRC, true
+}
+
+// IsARMMULA reports whether the op (as defined by an arm.A* constant) is
+// MULA, MULS, MMULA, MMULS, MULABB, MULAWB or MULAWT, the 4-operand instructions.
+func IsARMMULA(op obj.As) bool {
+	switch op {
+	case arm.AMULA, arm.AMULS, arm.AMMULA, arm.AMMULS, arm.AMULABB, arm.AMULAWB, arm.AMULAWT:
+		return true
+	}
+	return false
+}
+
+var bcode = []obj.As{
+	arm.ABEQ,
+	arm.ABNE,
+	arm.ABCS,
+	arm.ABCC,
+	arm.ABMI,
+	arm.ABPL,
+	arm.ABVS,
+	arm.ABVC,
+	arm.ABHI,
+	arm.ABLS,
+	arm.ABGE,
+	arm.ABLT,
+	arm.ABGT,
+	arm.ABLE,
+	arm.AB,
+	obj.ANOP,
+}
+
+// ARMConditionCodes handles the special condition code situation for the ARM.
+// It returns a boolean to indicate success; failure means cond was unrecognized.
+func ARMConditionCodes(prog *obj.Prog, cond string) bool {
+	if cond == "" {
+		return true
+	}
+	bits, ok := ParseARMCondition(cond)
+	if !ok {
+		return false
+	}
+	/* hack to make B.NE etc. work: turn it into the corresponding conditional */
+	if prog.As == arm.AB {
+		prog.As = bcode[(bits^arm.C_SCOND_XOR)&0xf]
+		bits = (bits &^ 0xf) | arm.C_SCOND_NONE
+	}
+	prog.Scond = bits
+	return true
+}
+
+// ParseARMCondition parses the conditions attached to an ARM instruction.
+// The input is a single string consisting of period-separated condition
+// codes, such as ".P.W". An initial period is ignored.
+func ParseARMCondition(cond string) (uint8, bool) {
+	return parseARMCondition(cond, armLS, armSCOND)
+}
+
+func parseARMCondition(cond string, ls, scond map[string]uint8) (uint8, bool) {
+	cond = strings.TrimPrefix(cond, ".")
+	if cond == "" {
+		return arm.C_SCOND_NONE, true
+	}
+	names := strings.Split(cond, ".")
+	bits := uint8(0)
+	for _, name := range names {
+		if b, present := ls[name]; present {
+			bits |= b
+			continue
+		}
+		if b, present := scond[name]; present {
+			bits = (bits &^ arm.C_SCOND) | b
+			continue
+		}
+		return 0, false
+	}
+	return bits, true
+}
+
+func armRegisterNumber(name string, n int16) (int16, bool) {
+	if n < 0 || 15 < n {
+		return 0, false
+	}
+	switch name {
+	case "R":
+		return arm.REG_R0 + n, true
+	case "F":
+		return arm.REG_F0 + n, true
+	}
+	return 0, false
+}