| // Copyright 2016 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 amd64 |
| |
| import ( |
| "fmt" |
| "math" |
| |
| "cmd/compile/internal/gc" |
| "cmd/compile/internal/ssa" |
| "cmd/internal/obj" |
| "cmd/internal/obj/x86" |
| ) |
| |
| // markMoves marks any MOVXconst ops that need to avoid clobbering flags. |
| func ssaMarkMoves(s *gc.SSAGenState, b *ssa.Block) { |
| flive := b.FlagsLiveAtEnd |
| if b.Control != nil && b.Control.Type.IsFlags() { |
| flive = true |
| } |
| for i := len(b.Values) - 1; i >= 0; i-- { |
| v := b.Values[i] |
| if flive && (v.Op == ssa.OpAMD64MOVLconst || v.Op == ssa.OpAMD64MOVQconst) { |
| // The "mark" is any non-nil Aux value. |
| v.Aux = v |
| } |
| if v.Type.IsFlags() { |
| flive = false |
| } |
| for _, a := range v.Args { |
| if a.Type.IsFlags() { |
| flive = true |
| } |
| } |
| } |
| } |
| |
| // loadByType returns the load instruction of the given type. |
| func loadByType(t ssa.Type) obj.As { |
| // Avoid partial register write |
| if !t.IsFloat() && t.Size() <= 2 { |
| if t.Size() == 1 { |
| return x86.AMOVBLZX |
| } else { |
| return x86.AMOVWLZX |
| } |
| } |
| // Otherwise, there's no difference between load and store opcodes. |
| return storeByType(t) |
| } |
| |
| // storeByType returns the store instruction of the given type. |
| func storeByType(t ssa.Type) obj.As { |
| width := t.Size() |
| if t.IsFloat() { |
| switch width { |
| case 4: |
| return x86.AMOVSS |
| case 8: |
| return x86.AMOVSD |
| } |
| } else { |
| switch width { |
| case 1: |
| return x86.AMOVB |
| case 2: |
| return x86.AMOVW |
| case 4: |
| return x86.AMOVL |
| case 8: |
| return x86.AMOVQ |
| } |
| } |
| panic("bad store type") |
| } |
| |
| // moveByType returns the reg->reg move instruction of the given type. |
| func moveByType(t ssa.Type) obj.As { |
| if t.IsFloat() { |
| // Moving the whole sse2 register is faster |
| // than moving just the correct low portion of it. |
| // There is no xmm->xmm move with 1 byte opcode, |
| // so use movups, which has 2 byte opcode. |
| return x86.AMOVUPS |
| } else { |
| switch t.Size() { |
| case 1: |
| // Avoids partial register write |
| return x86.AMOVL |
| case 2: |
| return x86.AMOVL |
| case 4: |
| return x86.AMOVL |
| case 8: |
| return x86.AMOVQ |
| case 16: |
| return x86.AMOVUPS // int128s are in SSE registers |
| default: |
| panic(fmt.Sprintf("bad int register width %d:%s", t.Size(), t)) |
| } |
| } |
| } |
| |
| // opregreg emits instructions for |
| // dest := dest(To) op src(From) |
| // and also returns the created obj.Prog so it |
| // may be further adjusted (offset, scale, etc). |
| func opregreg(op obj.As, dest, src int16) *obj.Prog { |
| p := gc.Prog(op) |
| p.From.Type = obj.TYPE_REG |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = dest |
| p.From.Reg = src |
| return p |
| } |
| |
| // DUFFZERO consists of repeated blocks of 4 MOVUPSs + ADD, |
| // See runtime/mkduff.go. |
| func duffStart(size int64) int64 { |
| x, _ := duff(size) |
| return x |
| } |
| func duffAdj(size int64) int64 { |
| _, x := duff(size) |
| return x |
| } |
| |
| // duff returns the offset (from duffzero, in bytes) and pointer adjust (in bytes) |
| // required to use the duffzero mechanism for a block of the given size. |
| func duff(size int64) (int64, int64) { |
| if size < 32 || size > 1024 || size%dzClearStep != 0 { |
| panic("bad duffzero size") |
| } |
| steps := size / dzClearStep |
| blocks := steps / dzBlockLen |
| steps %= dzBlockLen |
| off := dzBlockSize * (dzBlocks - blocks) |
| var adj int64 |
| if steps != 0 { |
| off -= dzAddSize |
| off -= dzMovSize * steps |
| adj -= dzClearStep * (dzBlockLen - steps) |
| } |
| return off, adj |
| } |
| |
| func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) { |
| s.SetLineno(v.Line) |
| switch v.Op { |
| case ssa.OpAMD64ADDQ, ssa.OpAMD64ADDL: |
| r := v.Reg() |
| r1 := v.Args[0].Reg() |
| r2 := v.Args[1].Reg() |
| switch { |
| case r == r1: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r2 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| case r == r2: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r1 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| default: |
| var asm obj.As |
| if v.Op == ssa.OpAMD64ADDQ { |
| asm = x86.ALEAQ |
| } else { |
| asm = x86.ALEAL |
| } |
| p := gc.Prog(asm) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = r1 |
| p.From.Scale = 1 |
| p.From.Index = r2 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| } |
| // 2-address opcode arithmetic |
| case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL, |
| ssa.OpAMD64MULQ, ssa.OpAMD64MULL, |
| ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL, |
| ssa.OpAMD64ORQ, ssa.OpAMD64ORL, |
| ssa.OpAMD64XORQ, ssa.OpAMD64XORL, |
| ssa.OpAMD64SHLQ, ssa.OpAMD64SHLL, |
| ssa.OpAMD64SHRQ, ssa.OpAMD64SHRL, ssa.OpAMD64SHRW, ssa.OpAMD64SHRB, |
| ssa.OpAMD64SARQ, ssa.OpAMD64SARL, ssa.OpAMD64SARW, ssa.OpAMD64SARB, |
| ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD, ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD, |
| ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD, |
| ssa.OpAMD64PXOR: |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| opregreg(v.Op.Asm(), r, v.Args[1].Reg()) |
| |
| case ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU: |
| // Arg[0] (the dividend) is in AX. |
| // Arg[1] (the divisor) can be in any other register. |
| // Result[0] (the quotient) is in AX. |
| // Result[1] (the remainder) is in DX. |
| r := v.Args[1].Reg() |
| |
| // Zero extend dividend. |
| c := gc.Prog(x86.AXORL) |
| c.From.Type = obj.TYPE_REG |
| c.From.Reg = x86.REG_DX |
| c.To.Type = obj.TYPE_REG |
| c.To.Reg = x86.REG_DX |
| |
| // Issue divide. |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r |
| |
| case ssa.OpAMD64DIVQ, ssa.OpAMD64DIVL, ssa.OpAMD64DIVW: |
| // Arg[0] (the dividend) is in AX. |
| // Arg[1] (the divisor) can be in any other register. |
| // Result[0] (the quotient) is in AX. |
| // Result[1] (the remainder) is in DX. |
| r := v.Args[1].Reg() |
| |
| // CPU faults upon signed overflow, which occurs when the most |
| // negative int is divided by -1. Handle divide by -1 as a special case. |
| var c *obj.Prog |
| switch v.Op { |
| case ssa.OpAMD64DIVQ: |
| c = gc.Prog(x86.ACMPQ) |
| case ssa.OpAMD64DIVL: |
| c = gc.Prog(x86.ACMPL) |
| case ssa.OpAMD64DIVW: |
| c = gc.Prog(x86.ACMPW) |
| } |
| c.From.Type = obj.TYPE_REG |
| c.From.Reg = r |
| c.To.Type = obj.TYPE_CONST |
| c.To.Offset = -1 |
| j1 := gc.Prog(x86.AJEQ) |
| j1.To.Type = obj.TYPE_BRANCH |
| |
| // Sign extend dividend. |
| switch v.Op { |
| case ssa.OpAMD64DIVQ: |
| gc.Prog(x86.ACQO) |
| case ssa.OpAMD64DIVL: |
| gc.Prog(x86.ACDQ) |
| case ssa.OpAMD64DIVW: |
| gc.Prog(x86.ACWD) |
| } |
| |
| // Issue divide. |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r |
| |
| // Skip over -1 fixup code. |
| j2 := gc.Prog(obj.AJMP) |
| j2.To.Type = obj.TYPE_BRANCH |
| |
| // Issue -1 fixup code. |
| // n / -1 = -n |
| n1 := gc.Prog(x86.ANEGQ) |
| n1.To.Type = obj.TYPE_REG |
| n1.To.Reg = x86.REG_AX |
| |
| // n % -1 == 0 |
| n2 := gc.Prog(x86.AXORL) |
| n2.From.Type = obj.TYPE_REG |
| n2.From.Reg = x86.REG_DX |
| n2.To.Type = obj.TYPE_REG |
| n2.To.Reg = x86.REG_DX |
| |
| // TODO(khr): issue only the -1 fixup code we need. |
| // For instance, if only the quotient is used, no point in zeroing the remainder. |
| |
| j1.To.Val = n1 |
| j2.To.Val = s.Pc() |
| |
| case ssa.OpAMD64HMULQ, ssa.OpAMD64HMULL, ssa.OpAMD64HMULW, ssa.OpAMD64HMULB, |
| ssa.OpAMD64HMULQU, ssa.OpAMD64HMULLU, ssa.OpAMD64HMULWU, ssa.OpAMD64HMULBU: |
| // the frontend rewrites constant division by 8/16/32 bit integers into |
| // HMUL by a constant |
| // SSA rewrites generate the 64 bit versions |
| |
| // Arg[0] is already in AX as it's the only register we allow |
| // and DX is the only output we care about (the high bits) |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[1].Reg() |
| |
| // IMULB puts the high portion in AH instead of DL, |
| // so move it to DL for consistency |
| if v.Type.Size() == 1 { |
| m := gc.Prog(x86.AMOVB) |
| m.From.Type = obj.TYPE_REG |
| m.From.Reg = x86.REG_AH |
| m.To.Type = obj.TYPE_REG |
| m.To.Reg = x86.REG_DX |
| } |
| |
| case ssa.OpAMD64AVGQU: |
| // compute (x+y)/2 unsigned. |
| // Do a 64-bit add, the overflow goes into the carry. |
| // Shift right once and pull the carry back into the 63rd bit. |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(x86.AADDQ) |
| p.From.Type = obj.TYPE_REG |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| p.From.Reg = v.Args[1].Reg() |
| p = gc.Prog(x86.ARCRQ) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 1 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| |
| case ssa.OpAMD64ADDQconst, ssa.OpAMD64ADDLconst: |
| r := v.Reg() |
| a := v.Args[0].Reg() |
| if r == a { |
| if v.AuxInt == 1 { |
| var asm obj.As |
| // Software optimization manual recommends add $1,reg. |
| // But inc/dec is 1 byte smaller. ICC always uses inc |
| // Clang/GCC choose depending on flags, but prefer add. |
| // Experiments show that inc/dec is both a little faster |
| // and make a binary a little smaller. |
| if v.Op == ssa.OpAMD64ADDQconst { |
| asm = x86.AINCQ |
| } else { |
| asm = x86.AINCL |
| } |
| p := gc.Prog(asm) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| return |
| } |
| if v.AuxInt == -1 { |
| var asm obj.As |
| if v.Op == ssa.OpAMD64ADDQconst { |
| asm = x86.ADECQ |
| } else { |
| asm = x86.ADECL |
| } |
| p := gc.Prog(asm) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| return |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| return |
| } |
| var asm obj.As |
| if v.Op == ssa.OpAMD64ADDQconst { |
| asm = x86.ALEAQ |
| } else { |
| asm = x86.ALEAL |
| } |
| p := gc.Prog(asm) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = a |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| |
| case ssa.OpAMD64CMOVQEQ, ssa.OpAMD64CMOVLEQ: |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| |
| case ssa.OpAMD64MULQconst, ssa.OpAMD64MULLconst: |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| // TODO: Teach doasm to compile the three-address multiply imul $c, r1, r2 |
| // then we don't need to use resultInArg0 for these ops. |
| //p.From3 = new(obj.Addr) |
| //p.From3.Type = obj.TYPE_REG |
| //p.From3.Reg = v.Args[0].Reg() |
| |
| case ssa.OpAMD64SUBQconst, ssa.OpAMD64SUBLconst, |
| ssa.OpAMD64ANDQconst, ssa.OpAMD64ANDLconst, |
| ssa.OpAMD64ORQconst, ssa.OpAMD64ORLconst, |
| ssa.OpAMD64XORQconst, ssa.OpAMD64XORLconst, |
| ssa.OpAMD64SHLQconst, ssa.OpAMD64SHLLconst, |
| ssa.OpAMD64SHRQconst, ssa.OpAMD64SHRLconst, ssa.OpAMD64SHRWconst, ssa.OpAMD64SHRBconst, |
| ssa.OpAMD64SARQconst, ssa.OpAMD64SARLconst, ssa.OpAMD64SARWconst, ssa.OpAMD64SARBconst, |
| ssa.OpAMD64ROLQconst, ssa.OpAMD64ROLLconst, ssa.OpAMD64ROLWconst, ssa.OpAMD64ROLBconst: |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| case ssa.OpAMD64SBBQcarrymask, ssa.OpAMD64SBBLcarrymask: |
| r := v.Reg() |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| case ssa.OpAMD64LEAQ1, ssa.OpAMD64LEAQ2, ssa.OpAMD64LEAQ4, ssa.OpAMD64LEAQ8: |
| r := v.Args[0].Reg() |
| i := v.Args[1].Reg() |
| p := gc.Prog(x86.ALEAQ) |
| switch v.Op { |
| case ssa.OpAMD64LEAQ1: |
| p.From.Scale = 1 |
| if i == x86.REG_SP { |
| r, i = i, r |
| } |
| case ssa.OpAMD64LEAQ2: |
| p.From.Scale = 2 |
| case ssa.OpAMD64LEAQ4: |
| p.From.Scale = 4 |
| case ssa.OpAMD64LEAQ8: |
| p.From.Scale = 8 |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = r |
| p.From.Index = i |
| gc.AddAux(&p.From, v) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64LEAQ, ssa.OpAMD64LEAL: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64CMPQ, ssa.OpAMD64CMPL, ssa.OpAMD64CMPW, ssa.OpAMD64CMPB, |
| ssa.OpAMD64TESTQ, ssa.OpAMD64TESTL, ssa.OpAMD64TESTW, ssa.OpAMD64TESTB: |
| opregreg(v.Op.Asm(), v.Args[1].Reg(), v.Args[0].Reg()) |
| case ssa.OpAMD64UCOMISS, ssa.OpAMD64UCOMISD: |
| // Go assembler has swapped operands for UCOMISx relative to CMP, |
| // must account for that right here. |
| opregreg(v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg()) |
| case ssa.OpAMD64CMPQconst, ssa.OpAMD64CMPLconst, ssa.OpAMD64CMPWconst, ssa.OpAMD64CMPBconst: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[0].Reg() |
| p.To.Type = obj.TYPE_CONST |
| p.To.Offset = v.AuxInt |
| case ssa.OpAMD64TESTQconst, ssa.OpAMD64TESTLconst, ssa.OpAMD64TESTWconst, ssa.OpAMD64TESTBconst: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Args[0].Reg() |
| case ssa.OpAMD64MOVLconst, ssa.OpAMD64MOVQconst: |
| x := v.Reg() |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = v.AuxInt |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = x |
| // If flags are live at this instruction, suppress the |
| // MOV $0,AX -> XOR AX,AX optimization. |
| if v.Aux != nil { |
| p.Mark |= x86.PRESERVEFLAGS |
| } |
| case ssa.OpAMD64MOVSSconst, ssa.OpAMD64MOVSDconst: |
| x := v.Reg() |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_FCONST |
| p.From.Val = math.Float64frombits(uint64(v.AuxInt)) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = x |
| case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVLQSXload, ssa.OpAMD64MOVOload: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64MOVQloadidx8, ssa.OpAMD64MOVSDloadidx8: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.From.Scale = 8 |
| p.From.Index = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64MOVLloadidx4, ssa.OpAMD64MOVSSloadidx4: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.From.Scale = 4 |
| p.From.Index = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64MOVWloadidx2: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.From.Scale = 2 |
| p.From.Index = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64MOVBloadidx1, ssa.OpAMD64MOVWloadidx1, ssa.OpAMD64MOVLloadidx1, ssa.OpAMD64MOVQloadidx1, ssa.OpAMD64MOVSSloadidx1, ssa.OpAMD64MOVSDloadidx1: |
| r := v.Args[0].Reg() |
| i := v.Args[1].Reg() |
| if i == x86.REG_SP { |
| r, i = i, r |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = r |
| p.From.Scale = 1 |
| p.From.Index = i |
| gc.AddAux(&p.From, v) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore, ssa.OpAMD64MOVOstore: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64MOVQstoreidx8, ssa.OpAMD64MOVSDstoreidx8: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[2].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| p.To.Scale = 8 |
| p.To.Index = v.Args[1].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64MOVSSstoreidx4, ssa.OpAMD64MOVLstoreidx4: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[2].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| p.To.Scale = 4 |
| p.To.Index = v.Args[1].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64MOVWstoreidx2: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[2].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| p.To.Scale = 2 |
| p.To.Index = v.Args[1].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64MOVBstoreidx1, ssa.OpAMD64MOVWstoreidx1, ssa.OpAMD64MOVLstoreidx1, ssa.OpAMD64MOVQstoreidx1, ssa.OpAMD64MOVSSstoreidx1, ssa.OpAMD64MOVSDstoreidx1: |
| r := v.Args[0].Reg() |
| i := v.Args[1].Reg() |
| if i == x86.REG_SP { |
| r, i = i, r |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[2].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = r |
| p.To.Scale = 1 |
| p.To.Index = i |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64MOVQstoreconst, ssa.OpAMD64MOVLstoreconst, ssa.OpAMD64MOVWstoreconst, ssa.OpAMD64MOVBstoreconst: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| sc := v.AuxValAndOff() |
| p.From.Offset = sc.Val() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| gc.AddAux2(&p.To, v, sc.Off()) |
| case ssa.OpAMD64MOVQstoreconstidx1, ssa.OpAMD64MOVQstoreconstidx8, ssa.OpAMD64MOVLstoreconstidx1, ssa.OpAMD64MOVLstoreconstidx4, ssa.OpAMD64MOVWstoreconstidx1, ssa.OpAMD64MOVWstoreconstidx2, ssa.OpAMD64MOVBstoreconstidx1: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_CONST |
| sc := v.AuxValAndOff() |
| p.From.Offset = sc.Val() |
| r := v.Args[0].Reg() |
| i := v.Args[1].Reg() |
| switch v.Op { |
| case ssa.OpAMD64MOVBstoreconstidx1, ssa.OpAMD64MOVWstoreconstidx1, ssa.OpAMD64MOVLstoreconstidx1, ssa.OpAMD64MOVQstoreconstidx1: |
| p.To.Scale = 1 |
| if i == x86.REG_SP { |
| r, i = i, r |
| } |
| case ssa.OpAMD64MOVWstoreconstidx2: |
| p.To.Scale = 2 |
| case ssa.OpAMD64MOVLstoreconstidx4: |
| p.To.Scale = 4 |
| case ssa.OpAMD64MOVQstoreconstidx8: |
| p.To.Scale = 8 |
| } |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = r |
| p.To.Index = i |
| gc.AddAux2(&p.To, v, sc.Off()) |
| case ssa.OpAMD64MOVLQSX, ssa.OpAMD64MOVWQSX, ssa.OpAMD64MOVBQSX, ssa.OpAMD64MOVLQZX, ssa.OpAMD64MOVWQZX, ssa.OpAMD64MOVBQZX, |
| ssa.OpAMD64CVTSL2SS, ssa.OpAMD64CVTSL2SD, ssa.OpAMD64CVTSQ2SS, ssa.OpAMD64CVTSQ2SD, |
| ssa.OpAMD64CVTTSS2SL, ssa.OpAMD64CVTTSD2SL, ssa.OpAMD64CVTTSS2SQ, ssa.OpAMD64CVTTSD2SQ, |
| ssa.OpAMD64CVTSS2SD, ssa.OpAMD64CVTSD2SS: |
| opregreg(v.Op.Asm(), v.Reg(), v.Args[0].Reg()) |
| case ssa.OpAMD64DUFFZERO: |
| off := duffStart(v.AuxInt) |
| adj := duffAdj(v.AuxInt) |
| var p *obj.Prog |
| if adj != 0 { |
| p = gc.Prog(x86.AADDQ) |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = adj |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = x86.REG_DI |
| } |
| p = gc.Prog(obj.ADUFFZERO) |
| p.To.Type = obj.TYPE_ADDR |
| p.To.Sym = gc.Linksym(gc.Pkglookup("duffzero", gc.Runtimepkg)) |
| p.To.Offset = off |
| case ssa.OpAMD64MOVOconst: |
| if v.AuxInt != 0 { |
| v.Fatalf("MOVOconst can only do constant=0") |
| } |
| r := v.Reg() |
| opregreg(x86.AXORPS, r, r) |
| case ssa.OpAMD64DUFFCOPY: |
| p := gc.Prog(obj.ADUFFCOPY) |
| p.To.Type = obj.TYPE_ADDR |
| p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg)) |
| p.To.Offset = v.AuxInt |
| |
| case ssa.OpCopy, ssa.OpAMD64MOVQconvert, ssa.OpAMD64MOVLconvert: // TODO: use MOVQreg for reg->reg copies instead of OpCopy? |
| if v.Type.IsMemory() { |
| return |
| } |
| x := v.Args[0].Reg() |
| y := v.Reg() |
| if x != y { |
| opregreg(moveByType(v.Type), y, x) |
| } |
| case ssa.OpLoadReg: |
| if v.Type.IsFlags() { |
| v.Fatalf("load flags not implemented: %v", v.LongString()) |
| return |
| } |
| p := gc.Prog(loadByType(v.Type)) |
| n, off := gc.AutoVar(v.Args[0]) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Node = n |
| p.From.Sym = gc.Linksym(n.Sym) |
| p.From.Offset = off |
| if n.Class == gc.PPARAM || n.Class == gc.PPARAMOUT { |
| p.From.Name = obj.NAME_PARAM |
| p.From.Offset += n.Xoffset |
| } else { |
| p.From.Name = obj.NAME_AUTO |
| } |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| |
| case ssa.OpStoreReg: |
| if v.Type.IsFlags() { |
| v.Fatalf("store flags not implemented: %v", v.LongString()) |
| return |
| } |
| p := gc.Prog(storeByType(v.Type)) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[0].Reg() |
| n, off := gc.AutoVar(v) |
| p.To.Type = obj.TYPE_MEM |
| p.To.Node = n |
| p.To.Sym = gc.Linksym(n.Sym) |
| p.To.Offset = off |
| if n.Class == gc.PPARAM || n.Class == gc.PPARAMOUT { |
| p.To.Name = obj.NAME_PARAM |
| p.To.Offset += n.Xoffset |
| } else { |
| p.To.Name = obj.NAME_AUTO |
| } |
| case ssa.OpPhi: |
| gc.CheckLoweredPhi(v) |
| case ssa.OpInitMem: |
| // memory arg needs no code |
| case ssa.OpArg: |
| // input args need no code |
| case ssa.OpAMD64LoweredGetClosurePtr: |
| // Closure pointer is DX. |
| gc.CheckLoweredGetClosurePtr(v) |
| case ssa.OpAMD64LoweredGetG: |
| r := v.Reg() |
| // See the comments in cmd/internal/obj/x86/obj6.go |
| // near CanUse1InsnTLS for a detailed explanation of these instructions. |
| if x86.CanUse1InsnTLS(gc.Ctxt) { |
| // MOVQ (TLS), r |
| p := gc.Prog(x86.AMOVQ) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = x86.REG_TLS |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| } else { |
| // MOVQ TLS, r |
| // MOVQ (r)(TLS*1), r |
| p := gc.Prog(x86.AMOVQ) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = x86.REG_TLS |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| q := gc.Prog(x86.AMOVQ) |
| q.From.Type = obj.TYPE_MEM |
| q.From.Reg = r |
| q.From.Index = x86.REG_TLS |
| q.From.Scale = 1 |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = r |
| } |
| case ssa.OpAMD64CALLstatic: |
| if v.Aux.(*gc.Sym) == gc.Deferreturn.Sym { |
| // Deferred calls will appear to be returning to |
| // the CALL deferreturn(SB) that we are about to emit. |
| // However, the stack trace code will show the line |
| // of the instruction byte before the return PC. |
| // To avoid that being an unrelated instruction, |
| // insert an actual hardware NOP that will have the right line number. |
| // This is different from obj.ANOP, which is a virtual no-op |
| // that doesn't make it into the instruction stream. |
| ginsnop() |
| } |
| p := gc.Prog(obj.ACALL) |
| p.To.Type = obj.TYPE_MEM |
| p.To.Name = obj.NAME_EXTERN |
| p.To.Sym = gc.Linksym(v.Aux.(*gc.Sym)) |
| if gc.Maxarg < v.AuxInt { |
| gc.Maxarg = v.AuxInt |
| } |
| case ssa.OpAMD64CALLclosure: |
| p := gc.Prog(obj.ACALL) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Args[0].Reg() |
| if gc.Maxarg < v.AuxInt { |
| gc.Maxarg = v.AuxInt |
| } |
| case ssa.OpAMD64CALLdefer: |
| p := gc.Prog(obj.ACALL) |
| p.To.Type = obj.TYPE_MEM |
| p.To.Name = obj.NAME_EXTERN |
| p.To.Sym = gc.Linksym(gc.Deferproc.Sym) |
| if gc.Maxarg < v.AuxInt { |
| gc.Maxarg = v.AuxInt |
| } |
| case ssa.OpAMD64CALLgo: |
| p := gc.Prog(obj.ACALL) |
| p.To.Type = obj.TYPE_MEM |
| p.To.Name = obj.NAME_EXTERN |
| p.To.Sym = gc.Linksym(gc.Newproc.Sym) |
| if gc.Maxarg < v.AuxInt { |
| gc.Maxarg = v.AuxInt |
| } |
| case ssa.OpAMD64CALLinter: |
| p := gc.Prog(obj.ACALL) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Args[0].Reg() |
| if gc.Maxarg < v.AuxInt { |
| gc.Maxarg = v.AuxInt |
| } |
| case ssa.OpAMD64NEGQ, ssa.OpAMD64NEGL, |
| ssa.OpAMD64BSWAPQ, ssa.OpAMD64BSWAPL, |
| ssa.OpAMD64NOTQ, ssa.OpAMD64NOTL: |
| r := v.Reg() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = r |
| case ssa.OpAMD64BSFQ, ssa.OpAMD64BSFL: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[0].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg0() |
| case ssa.OpAMD64SQRTSD: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[0].Reg() |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| case ssa.OpSP, ssa.OpSB: |
| // nothing to do |
| case ssa.OpSelect0, ssa.OpSelect1: |
| // nothing to do |
| case ssa.OpAMD64SETEQ, ssa.OpAMD64SETNE, |
| ssa.OpAMD64SETL, ssa.OpAMD64SETLE, |
| ssa.OpAMD64SETG, ssa.OpAMD64SETGE, |
| ssa.OpAMD64SETGF, ssa.OpAMD64SETGEF, |
| ssa.OpAMD64SETB, ssa.OpAMD64SETBE, |
| ssa.OpAMD64SETORD, ssa.OpAMD64SETNAN, |
| ssa.OpAMD64SETA, ssa.OpAMD64SETAE: |
| p := gc.Prog(v.Op.Asm()) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| |
| case ssa.OpAMD64SETNEF: |
| p := gc.Prog(v.Op.Asm()) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| q := gc.Prog(x86.ASETPS) |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = x86.REG_AX |
| // ORL avoids partial register write and is smaller than ORQ, used by old compiler |
| opregreg(x86.AORL, v.Reg(), x86.REG_AX) |
| |
| case ssa.OpAMD64SETEQF: |
| p := gc.Prog(v.Op.Asm()) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg() |
| q := gc.Prog(x86.ASETPC) |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = x86.REG_AX |
| // ANDL avoids partial register write and is smaller than ANDQ, used by old compiler |
| opregreg(x86.AANDL, v.Reg(), x86.REG_AX) |
| |
| case ssa.OpAMD64InvertFlags: |
| v.Fatalf("InvertFlags should never make it to codegen %v", v.LongString()) |
| case ssa.OpAMD64FlagEQ, ssa.OpAMD64FlagLT_ULT, ssa.OpAMD64FlagLT_UGT, ssa.OpAMD64FlagGT_ULT, ssa.OpAMD64FlagGT_UGT: |
| v.Fatalf("Flag* ops should never make it to codegen %v", v.LongString()) |
| case ssa.OpAMD64AddTupleFirst32, ssa.OpAMD64AddTupleFirst64: |
| v.Fatalf("AddTupleFirst* should never make it to codegen %v", v.LongString()) |
| case ssa.OpAMD64REPSTOSQ: |
| gc.Prog(x86.AREP) |
| gc.Prog(x86.ASTOSQ) |
| case ssa.OpAMD64REPMOVSQ: |
| gc.Prog(x86.AREP) |
| gc.Prog(x86.AMOVSQ) |
| case ssa.OpVarDef: |
| gc.Gvardef(v.Aux.(*gc.Node)) |
| case ssa.OpVarKill: |
| gc.Gvarkill(v.Aux.(*gc.Node)) |
| case ssa.OpVarLive: |
| gc.Gvarlive(v.Aux.(*gc.Node)) |
| case ssa.OpKeepAlive: |
| gc.KeepAlive(v) |
| case ssa.OpAMD64LoweredNilCheck: |
| // Issue a load which will fault if the input is nil. |
| // TODO: We currently use the 2-byte instruction TESTB AX, (reg). |
| // Should we use the 3-byte TESTB $0, (reg) instead? It is larger |
| // but it doesn't have false dependency on AX. |
| // Or maybe allocate an output register and use MOVL (reg),reg2 ? |
| // That trades clobbering flags for clobbering a register. |
| p := gc.Prog(x86.ATESTB) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = x86.REG_AX |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.To, v) |
| if gc.Debug_checknil != 0 && v.Line > 1 { // v.Line==1 in generated wrappers |
| gc.Warnl(v.Line, "generated nil check") |
| } |
| case ssa.OpAMD64MOVLatomicload, ssa.OpAMD64MOVQatomicload: |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.From, v) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg0() |
| case ssa.OpAMD64XCHGL, ssa.OpAMD64XCHGQ: |
| r := v.Reg0() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output[0] not in same register %s", v.LongString()) |
| } |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[1].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64XADDLlock, ssa.OpAMD64XADDQlock: |
| r := v.Reg0() |
| if r != v.Args[0].Reg() { |
| v.Fatalf("input[0] and output[0] not in same register %s", v.LongString()) |
| } |
| gc.Prog(x86.ALOCK) |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = r |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[1].Reg() |
| gc.AddAux(&p.To, v) |
| case ssa.OpAMD64CMPXCHGLlock, ssa.OpAMD64CMPXCHGQlock: |
| if v.Args[1].Reg() != x86.REG_AX { |
| v.Fatalf("input[1] not in AX %s", v.LongString()) |
| } |
| gc.Prog(x86.ALOCK) |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[2].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.To, v) |
| p = gc.Prog(x86.ASETEQ) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = v.Reg0() |
| case ssa.OpAMD64ANDBlock, ssa.OpAMD64ORBlock: |
| gc.Prog(x86.ALOCK) |
| p := gc.Prog(v.Op.Asm()) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = v.Args[1].Reg() |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = v.Args[0].Reg() |
| gc.AddAux(&p.To, v) |
| default: |
| v.Fatalf("genValue not implemented: %s", v.LongString()) |
| } |
| } |
| |
| var blockJump = [...]struct { |
| asm, invasm obj.As |
| }{ |
| ssa.BlockAMD64EQ: {x86.AJEQ, x86.AJNE}, |
| ssa.BlockAMD64NE: {x86.AJNE, x86.AJEQ}, |
| ssa.BlockAMD64LT: {x86.AJLT, x86.AJGE}, |
| ssa.BlockAMD64GE: {x86.AJGE, x86.AJLT}, |
| ssa.BlockAMD64LE: {x86.AJLE, x86.AJGT}, |
| ssa.BlockAMD64GT: {x86.AJGT, x86.AJLE}, |
| ssa.BlockAMD64ULT: {x86.AJCS, x86.AJCC}, |
| ssa.BlockAMD64UGE: {x86.AJCC, x86.AJCS}, |
| ssa.BlockAMD64UGT: {x86.AJHI, x86.AJLS}, |
| ssa.BlockAMD64ULE: {x86.AJLS, x86.AJHI}, |
| ssa.BlockAMD64ORD: {x86.AJPC, x86.AJPS}, |
| ssa.BlockAMD64NAN: {x86.AJPS, x86.AJPC}, |
| } |
| |
| var eqfJumps = [2][2]gc.FloatingEQNEJump{ |
| {{Jump: x86.AJNE, Index: 1}, {Jump: x86.AJPS, Index: 1}}, // next == b.Succs[0] |
| {{Jump: x86.AJNE, Index: 1}, {Jump: x86.AJPC, Index: 0}}, // next == b.Succs[1] |
| } |
| var nefJumps = [2][2]gc.FloatingEQNEJump{ |
| {{Jump: x86.AJNE, Index: 0}, {Jump: x86.AJPC, Index: 1}}, // next == b.Succs[0] |
| {{Jump: x86.AJNE, Index: 0}, {Jump: x86.AJPS, Index: 0}}, // next == b.Succs[1] |
| } |
| |
| func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) { |
| s.SetLineno(b.Line) |
| |
| switch b.Kind { |
| case ssa.BlockPlain: |
| if b.Succs[0].Block() != next { |
| p := gc.Prog(obj.AJMP) |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()}) |
| } |
| case ssa.BlockDefer: |
| // defer returns in rax: |
| // 0 if we should continue executing |
| // 1 if we should jump to deferreturn call |
| p := gc.Prog(x86.ATESTL) |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = x86.REG_AX |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = x86.REG_AX |
| p = gc.Prog(x86.AJNE) |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()}) |
| if b.Succs[0].Block() != next { |
| p := gc.Prog(obj.AJMP) |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()}) |
| } |
| case ssa.BlockExit: |
| gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here |
| case ssa.BlockRet: |
| gc.Prog(obj.ARET) |
| case ssa.BlockRetJmp: |
| p := gc.Prog(obj.AJMP) |
| p.To.Type = obj.TYPE_MEM |
| p.To.Name = obj.NAME_EXTERN |
| p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym)) |
| |
| case ssa.BlockAMD64EQF: |
| gc.SSAGenFPJump(s, b, next, &eqfJumps) |
| |
| case ssa.BlockAMD64NEF: |
| gc.SSAGenFPJump(s, b, next, &nefJumps) |
| |
| case ssa.BlockAMD64EQ, ssa.BlockAMD64NE, |
| ssa.BlockAMD64LT, ssa.BlockAMD64GE, |
| ssa.BlockAMD64LE, ssa.BlockAMD64GT, |
| ssa.BlockAMD64ULT, ssa.BlockAMD64UGT, |
| ssa.BlockAMD64ULE, ssa.BlockAMD64UGE: |
| jmp := blockJump[b.Kind] |
| likely := b.Likely |
| var p *obj.Prog |
| switch next { |
| case b.Succs[0].Block(): |
| p = gc.Prog(jmp.invasm) |
| likely *= -1 |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()}) |
| case b.Succs[1].Block(): |
| p = gc.Prog(jmp.asm) |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()}) |
| default: |
| p = gc.Prog(jmp.asm) |
| p.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()}) |
| q := gc.Prog(obj.AJMP) |
| q.To.Type = obj.TYPE_BRANCH |
| s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()}) |
| } |
| |
| // liblink reorders the instruction stream as it sees fit. |
| // Pass along what we know so liblink can make use of it. |
| // TODO: Once we've fully switched to SSA, |
| // make liblink leave our output alone. |
| switch likely { |
| case ssa.BranchUnlikely: |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 0 |
| case ssa.BranchLikely: |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 1 |
| } |
| |
| default: |
| b.Fatalf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString()) |
| } |
| } |
