1 files changed, 164 insertions, 0 deletions
diff --git a/src/cmd/internal/rsc.io/arm/armasm/gnu.go b/src/cmd/internal/rsc.io/arm/armasm/gnu.go
new file mode 100644
index 000000000..1a97a5a84
--- /dev/null
+++ b/src/cmd/internal/rsc.io/arm/armasm/gnu.go
@@ -0,0 +1,164 @@
+// Copyright 2014 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.
+
+package armasm
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+var saveDot = strings.NewReplacer(
+	".F16", "_dot_F16",
+	".F32", "_dot_F32",
+	".F64", "_dot_F64",
+	".S32", "_dot_S32",
+	".U32", "_dot_U32",
+	".FXS", "_dot_S",
+	".FXU", "_dot_U",
+	".32", "_dot_32",
+)
+
+// GNUSyntax returns the GNU assembler syntax for the instruction, as defined by GNU binutils.
+// This form typically matches the syntax defined in the ARM Reference Manual.
+func GNUSyntax(inst Inst) string {
+	var buf bytes.Buffer
+	op := inst.Op.String()
+	op = saveDot.Replace(op)
+	op = strings.Replace(op, ".", "", -1)
+	op = strings.Replace(op, "_dot_", ".", -1)
+	op = strings.ToLower(op)
+	buf.WriteString(op)
+	sep := " "
+	for i, arg := range inst.Args {
+		if arg == nil {
+			break
+		}
+		text := gnuArg(&inst, i, arg)
+		if text == "" {
+			continue
+		}
+		buf.WriteString(sep)
+		sep = ", "
+		buf.WriteString(text)
+	}
+	return buf.String()
+}
+
+func gnuArg(inst *Inst, argIndex int, arg Arg) string {
+	switch inst.Op &^ 15 {
+	case LDRD_EQ, LDREXD_EQ, STRD_EQ:
+		if argIndex == 1 {
+			// second argument in consecutive pair not printed
+			return ""
+		}
+	case STREXD_EQ:
+		if argIndex == 2 {
+			// second argument in consecutive pair not printed
+			return ""
+		}
+	}
+
+	switch arg := arg.(type) {
+	case Imm:
+		switch inst.Op &^ 15 {
+		case BKPT_EQ:
+			return fmt.Sprintf("%#04x", uint32(arg))
+		case SVC_EQ:
+			return fmt.Sprintf("%#08x", uint32(arg))
+		}
+		return fmt.Sprintf("#%d", int32(arg))
+
+	case ImmAlt:
+		return fmt.Sprintf("#%d, %d", arg.Val, arg.Rot)
+
+	case Mem:
+		R := gnuArg(inst, -1, arg.Base)
+		X := ""
+		if arg.Sign != 0 {
+			X = ""
+			if arg.Sign < 0 {
+				X = "-"
+			}
+			X += gnuArg(inst, -1, arg.Index)
+			if arg.Shift == ShiftLeft && arg.Count == 0 {
+				// nothing
+			} else if arg.Shift == RotateRightExt {
+				X += ", rrx"
+			} else {
+				X += fmt.Sprintf(", %s #%d", strings.ToLower(arg.Shift.String()), arg.Count)
+			}
+		} else {
+			X = fmt.Sprintf("#%d", arg.Offset)
+		}
+
+		switch arg.Mode {
+		case AddrOffset:
+			if X == "#0" {
+				return fmt.Sprintf("[%s]", R)
+			}
+			return fmt.Sprintf("[%s, %s]", R, X)
+		case AddrPreIndex:
+			return fmt.Sprintf("[%s, %s]!", R, X)
+		case AddrPostIndex:
+			return fmt.Sprintf("[%s], %s", R, X)
+		case AddrLDM:
+			if X == "#0" {
+				return R
+			}
+		case AddrLDM_WB:
+			if X == "#0" {
+				return R + "!"
+			}
+		}
+		return fmt.Sprintf("[%s Mode(%d) %s]", R, int(arg.Mode), X)
+
+	case PCRel:
+		return fmt.Sprintf(".%+#x", int32(arg)+4)
+
+	case Reg:
+		switch inst.Op &^ 15 {
+		case LDREX_EQ:
+			if argIndex == 0 {
+				return fmt.Sprintf("r%d", int32(arg))
+			}
+		}
+		switch arg {
+		case R10:
+			return "sl"
+		case R11:
+			return "fp"
+		case R12:
+			return "ip"
+		}
+
+	case RegList:
+		var buf bytes.Buffer
+		fmt.Fprintf(&buf, "{")
+		sep := ""
+		for i := 0; i < 16; i++ {
+			if arg&(1<<uint(i)) != 0 {
+				fmt.Fprintf(&buf, "%s%s", sep, gnuArg(inst, -1, Reg(i)))
+				sep = ", "
+			}
+		}
+		fmt.Fprintf(&buf, "}")
+		return buf.String()
+
+	case RegShift:
+		if arg.Shift == ShiftLeft && arg.Count == 0 {
+			return gnuArg(inst, -1, arg.Reg)
+		}
+		if arg.Shift == RotateRightExt {
+			return gnuArg(inst, -1, arg.Reg) + ", rrx"
+		}
+		return fmt.Sprintf("%s, %s #%d", gnuArg(inst, -1, arg.Reg), strings.ToLower(arg.Shift.String()), arg.Count)
+
+	case RegShiftReg:
+		return fmt.Sprintf("%s, %s %s", gnuArg(inst, -1, arg.Reg), strings.ToLower(arg.Shift.String()), gnuArg(inst, -1, arg.RegCount))
+
+	}
+	return strings.ToLower(arg.String())
+}