mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-23 09:21:35 +00:00
126 lines
3.0 KiB
Go
126 lines
3.0 KiB
Go
// 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 ppc64asm
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
// GNUSyntax returns the GNU assembler syntax for the instruction, as defined by GNU binutils.
|
|
// This form typically matches the syntax defined in the Power ISA Reference Manual.
|
|
func GNUSyntax(inst Inst) string {
|
|
var buf bytes.Buffer
|
|
if inst.Op == 0 {
|
|
return "error: unkown instruction"
|
|
}
|
|
buf.WriteString(inst.Op.String())
|
|
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()
|
|
}
|
|
|
|
// gnuArg formats arg (which is the argIndex's arg in inst) according to GNU rules.
|
|
// NOTE: because GNUSyntax is the only caller of this func, and it receives a copy
|
|
// of inst, it's ok to modify inst.Args here.
|
|
func gnuArg(inst *Inst, argIndex int, arg Arg) string {
|
|
// special cases for load/store instructions
|
|
if _, ok := arg.(Offset); ok {
|
|
if argIndex+1 == len(inst.Args) || inst.Args[argIndex+1] == nil {
|
|
panic(fmt.Errorf("wrong table: offset not followed by register"))
|
|
}
|
|
}
|
|
switch arg := arg.(type) {
|
|
case Reg:
|
|
if isLoadStoreOp(inst.Op) && argIndex == 1 && arg == R0 {
|
|
return "0"
|
|
}
|
|
return arg.String()
|
|
case CondReg:
|
|
if arg == CR0 && strings.HasPrefix(inst.Op.String(), "cmp") {
|
|
return "" // don't show cr0 for cmp instructions
|
|
} else if arg >= CR0 {
|
|
return fmt.Sprintf("cr%d", int(arg-CR0))
|
|
}
|
|
bit := [4]string{"lt", "gt", "eq", "so"}[(arg-Cond0LT)%4]
|
|
if arg <= Cond0SO {
|
|
return bit
|
|
}
|
|
return fmt.Sprintf("4*cr%d+%s", int(arg-Cond0LT)/4, bit)
|
|
case Imm:
|
|
return fmt.Sprintf("%d", arg)
|
|
case SpReg:
|
|
return fmt.Sprintf("%d", int(arg))
|
|
case PCRel:
|
|
return fmt.Sprintf(".%+#x", int(arg))
|
|
case Label:
|
|
return fmt.Sprintf("%#x", uint32(arg))
|
|
case Offset:
|
|
reg := inst.Args[argIndex+1].(Reg)
|
|
removeArg(inst, argIndex+1)
|
|
if reg == R0 {
|
|
return fmt.Sprintf("%d(0)", int(arg))
|
|
}
|
|
return fmt.Sprintf("%d(r%d)", int(arg), reg-R0)
|
|
}
|
|
return fmt.Sprintf("???(%v)", arg)
|
|
}
|
|
|
|
// removeArg removes the arg in inst.Args[index].
|
|
func removeArg(inst *Inst, index int) {
|
|
for i := index; i < len(inst.Args); i++ {
|
|
if i+1 < len(inst.Args) {
|
|
inst.Args[i] = inst.Args[i+1]
|
|
} else {
|
|
inst.Args[i] = nil
|
|
}
|
|
}
|
|
}
|
|
|
|
// isLoadStoreOp returns true if op is a load or store instruction
|
|
func isLoadStoreOp(op Op) bool {
|
|
switch op {
|
|
case LBZ, LBZU, LBZX, LBZUX:
|
|
return true
|
|
case LHZ, LHZU, LHZX, LHZUX:
|
|
return true
|
|
case LHA, LHAU, LHAX, LHAUX:
|
|
return true
|
|
case LWZ, LWZU, LWZX, LWZUX:
|
|
return true
|
|
case LWA, LWAX, LWAUX:
|
|
return true
|
|
case LD, LDU, LDX, LDUX:
|
|
return true
|
|
case LQ:
|
|
return true
|
|
case STB, STBU, STBX, STBUX:
|
|
return true
|
|
case STH, STHU, STHX, STHUX:
|
|
return true
|
|
case STW, STWU, STWX, STWUX:
|
|
return true
|
|
case STD, STDU, STDX, STDUX:
|
|
return true
|
|
case STQ:
|
|
return true
|
|
case LHBRX, LWBRX, STHBRX, STWBRX:
|
|
return true
|
|
}
|
|
return false
|
|
}
|