| // cmd/7l/noop.c, cmd/7l/obj.c, cmd/ld/pass.c from Vita Nuova. |
| // https://code.google.com/p/ken-cc/source/browse/ |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) |
| // Portions Copyright © 1997-1999 Vita Nuova Limited |
| // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) |
| // Portions Copyright © 2004,2006 Bruce Ellis |
| // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) |
| // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others |
| // Portions Copyright © 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package arm64 |
| |
| import ( |
| "cmd/internal/obj" |
| "cmd/internal/objabi" |
| "cmd/internal/src" |
| "cmd/internal/sys" |
| "internal/buildcfg" |
| "log" |
| "math" |
| ) |
| |
| var complements = []obj.As{ |
| AADD: ASUB, |
| AADDW: ASUBW, |
| ASUB: AADD, |
| ASUBW: AADDW, |
| ACMP: ACMN, |
| ACMPW: ACMNW, |
| ACMN: ACMP, |
| ACMNW: ACMPW, |
| } |
| |
| // noZRreplace is the set of instructions for which $0 in the To operand |
| // should NOT be replaced with REGZERO. |
| var noZRreplace = map[obj.As]bool{ |
| APRFM: true, |
| } |
| |
| func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog { |
| if c.ctxt.Flag_maymorestack != "" { |
| p = c.cursym.Func().SpillRegisterArgs(p, c.newprog) |
| |
| // Save LR and make room for FP, REGCTXT. Leave room |
| // for caller's saved FP. |
| const frameSize = 32 |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| p.To.Type = obj.TYPE_MEM |
| p.Scond = C_XPRE |
| p.To.Offset = -frameSize |
| p.To.Reg = REGSP |
| p.Spadj = frameSize |
| |
| // Save FP. |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGFP |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REGSP |
| p.To.Offset = -8 |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ASUB |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 8 |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGFP |
| |
| // Save REGCTXT (for simplicity we do this whether or |
| // not we need it.) |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGCTXT |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REGSP |
| p.To.Offset = 8 |
| |
| // BL maymorestack |
| p = obj.Appendp(p, c.newprog) |
| p.As = ABL |
| p.To.Type = obj.TYPE_BRANCH |
| // See ../x86/obj6.go |
| p.To.Sym = c.ctxt.LookupABI(c.ctxt.Flag_maymorestack, c.cursym.ABI()) |
| |
| // Restore REGCTXT. |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGSP |
| p.From.Offset = 8 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGCTXT |
| |
| // Restore FP. |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGSP |
| p.From.Offset = -8 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGFP |
| |
| // Restore LR and SP. |
| p = obj.Appendp(p, c.newprog) |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.Scond = C_XPOST |
| p.From.Offset = frameSize |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGLINK |
| p.Spadj = -frameSize |
| |
| p = c.cursym.Func().UnspillRegisterArgs(p, c.newprog) |
| } |
| |
| // Jump back to here after morestack returns. |
| startPred := p |
| |
| // MOV g_stackguard(g), RT1 |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGG |
| p.From.Offset = 2 * int64(c.ctxt.Arch.PtrSize) // G.stackguard0 |
| if c.cursym.CFunc() { |
| p.From.Offset = 3 * int64(c.ctxt.Arch.PtrSize) // G.stackguard1 |
| } |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGRT1 |
| |
| // Mark the stack bound check and morestack call async nonpreemptible. |
| // If we get preempted here, when resumed the preemption request is |
| // cleared, but we'll still call morestack, which will double the stack |
| // unnecessarily. See issue #35470. |
| p = c.ctxt.StartUnsafePoint(p, c.newprog) |
| |
| q := (*obj.Prog)(nil) |
| if framesize <= objabi.StackSmall { |
| // small stack: SP < stackguard |
| // CMP stackguard, SP |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGRT1 |
| p.Reg = REGSP |
| } else if framesize <= objabi.StackBig { |
| // large stack: SP-framesize < stackguard-StackSmall |
| // SUB $(framesize-StackSmall), SP, RT2 |
| // CMP stackguard, RT2 |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = ASUB |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(framesize) - objabi.StackSmall |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGRT2 |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGRT1 |
| p.Reg = REGRT2 |
| } else { |
| // Such a large stack we need to protect against underflow. |
| // The runtime guarantees SP > objabi.StackBig, but |
| // framesize is large enough that SP-framesize may |
| // underflow, causing a direct comparison with the |
| // stack guard to incorrectly succeed. We explicitly |
| // guard against underflow. |
| // |
| // SUBS $(framesize-StackSmall), SP, RT2 |
| // // On underflow, jump to morestack |
| // BLO label_of_call_to_morestack |
| // CMP stackguard, RT2 |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ASUBS |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(framesize) - objabi.StackSmall |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGRT2 |
| |
| p = obj.Appendp(p, c.newprog) |
| q = p |
| p.As = ABLO |
| p.To.Type = obj.TYPE_BRANCH |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGRT1 |
| p.Reg = REGRT2 |
| } |
| |
| // BLS do-morestack |
| bls := obj.Appendp(p, c.newprog) |
| bls.As = ABLS |
| bls.To.Type = obj.TYPE_BRANCH |
| |
| end := c.ctxt.EndUnsafePoint(bls, c.newprog, -1) |
| |
| var last *obj.Prog |
| for last = c.cursym.Func().Text; last.Link != nil; last = last.Link { |
| } |
| |
| // Now we are at the end of the function, but logically |
| // we are still in function prologue. We need to fix the |
| // SP data and PCDATA. |
| spfix := obj.Appendp(last, c.newprog) |
| spfix.As = obj.ANOP |
| spfix.Spadj = -framesize |
| |
| pcdata := c.ctxt.EmitEntryStackMap(c.cursym, spfix, c.newprog) |
| pcdata = c.ctxt.StartUnsafePoint(pcdata, c.newprog) |
| |
| if q != nil { |
| q.To.SetTarget(pcdata) |
| } |
| bls.To.SetTarget(pcdata) |
| |
| spill := c.cursym.Func().SpillRegisterArgs(pcdata, c.newprog) |
| |
| // MOV LR, R3 |
| movlr := obj.Appendp(spill, c.newprog) |
| movlr.As = AMOVD |
| movlr.From.Type = obj.TYPE_REG |
| movlr.From.Reg = REGLINK |
| movlr.To.Type = obj.TYPE_REG |
| movlr.To.Reg = REG_R3 |
| |
| debug := movlr |
| if false { |
| debug = obj.Appendp(debug, c.newprog) |
| debug.As = AMOVD |
| debug.From.Type = obj.TYPE_CONST |
| debug.From.Offset = int64(framesize) |
| debug.To.Type = obj.TYPE_REG |
| debug.To.Reg = REGTMP |
| } |
| |
| // BL runtime.morestack(SB) |
| call := obj.Appendp(debug, c.newprog) |
| call.As = ABL |
| call.To.Type = obj.TYPE_BRANCH |
| morestack := "runtime.morestack" |
| switch { |
| case c.cursym.CFunc(): |
| morestack = "runtime.morestackc" |
| case !c.cursym.Func().Text.From.Sym.NeedCtxt(): |
| morestack = "runtime.morestack_noctxt" |
| } |
| call.To.Sym = c.ctxt.Lookup(morestack) |
| |
| unspill := c.cursym.Func().UnspillRegisterArgs(call, c.newprog) |
| pcdata = c.ctxt.EndUnsafePoint(unspill, c.newprog, -1) |
| |
| // B start |
| jmp := obj.Appendp(pcdata, c.newprog) |
| jmp.As = AB |
| jmp.To.Type = obj.TYPE_BRANCH |
| jmp.To.SetTarget(startPred.Link) |
| jmp.Spadj = +framesize |
| |
| return end |
| } |
| |
| func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) { |
| c := ctxt7{ctxt: ctxt, newprog: newprog} |
| |
| p.From.Class = 0 |
| p.To.Class = 0 |
| |
| // $0 results in C_ZCON, which matches both C_REG and various |
| // C_xCON, however the C_REG cases in asmout don't expect a |
| // constant, so they will use the register fields and assemble |
| // a R0. To prevent that, rewrite $0 as ZR. |
| if p.From.Type == obj.TYPE_CONST && p.From.Offset == 0 { |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGZERO |
| } |
| if p.To.Type == obj.TYPE_CONST && p.To.Offset == 0 && !noZRreplace[p.As] { |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGZERO |
| } |
| |
| // Rewrite BR/BL to symbol as TYPE_BRANCH. |
| switch p.As { |
| case AB, |
| ABL, |
| obj.ARET, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| if p.To.Sym != nil { |
| p.To.Type = obj.TYPE_BRANCH |
| } |
| break |
| } |
| |
| // Rewrite float constants to values stored in memory. |
| switch p.As { |
| case AFMOVS: |
| if p.From.Type == obj.TYPE_FCONST { |
| f64 := p.From.Val.(float64) |
| f32 := float32(f64) |
| if c.chipfloat7(f64) > 0 { |
| break |
| } |
| if math.Float32bits(f32) == 0 { |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGZERO |
| break |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = c.ctxt.Float32Sym(f32) |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| |
| case AFMOVD: |
| if p.From.Type == obj.TYPE_FCONST { |
| f64 := p.From.Val.(float64) |
| if c.chipfloat7(f64) > 0 { |
| break |
| } |
| if math.Float64bits(f64) == 0 { |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGZERO |
| break |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = c.ctxt.Float64Sym(f64) |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| |
| break |
| } |
| |
| // Rewrite negative immediates as positive immediates with |
| // complementary instruction. |
| switch p.As { |
| case AADD, ASUB, ACMP, ACMN: |
| if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && p.From.Offset != -1<<63 { |
| p.From.Offset = -p.From.Offset |
| p.As = complements[p.As] |
| } |
| case AADDW, ASUBW, ACMPW, ACMNW: |
| if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && int32(p.From.Offset) != -1<<31 { |
| p.From.Offset = -p.From.Offset |
| p.As = complements[p.As] |
| } |
| } |
| |
| if c.ctxt.Flag_dynlink { |
| c.rewriteToUseGot(p) |
| } |
| } |
| |
| // Rewrite p, if necessary, to access global data via the global offset table. |
| func (c *ctxt7) rewriteToUseGot(p *obj.Prog) { |
| if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO { |
| // ADUFFxxx $offset |
| // becomes |
| // MOVD runtime.duffxxx@GOT, REGTMP |
| // ADD $offset, REGTMP |
| // CALL REGTMP |
| var sym *obj.LSym |
| if p.As == obj.ADUFFZERO { |
| sym = c.ctxt.LookupABI("runtime.duffzero", obj.ABIInternal) |
| } else { |
| sym = c.ctxt.LookupABI("runtime.duffcopy", obj.ABIInternal) |
| } |
| offset := p.To.Offset |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.From.Name = obj.NAME_GOTREF |
| p.From.Sym = sym |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGTMP |
| p.To.Name = obj.NAME_NONE |
| p.To.Offset = 0 |
| p.To.Sym = nil |
| p1 := obj.Appendp(p, c.newprog) |
| p1.As = AADD |
| p1.From.Type = obj.TYPE_CONST |
| p1.From.Offset = offset |
| p1.To.Type = obj.TYPE_REG |
| p1.To.Reg = REGTMP |
| p2 := obj.Appendp(p1, c.newprog) |
| p2.As = obj.ACALL |
| p2.To.Type = obj.TYPE_REG |
| p2.To.Reg = REGTMP |
| } |
| |
| // We only care about global data: NAME_EXTERN means a global |
| // symbol in the Go sense, and p.Sym.Local is true for a few |
| // internally defined symbols. |
| if p.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() { |
| // MOVD $sym, Rx becomes MOVD sym@GOT, Rx |
| // MOVD $sym+<off>, Rx becomes MOVD sym@GOT, Rx; ADD <off>, Rx |
| if p.As != AMOVD { |
| c.ctxt.Diag("do not know how to handle TYPE_ADDR in %v with -dynlink", p) |
| } |
| if p.To.Type != obj.TYPE_REG { |
| c.ctxt.Diag("do not know how to handle LEAQ-type insn to non-register in %v with -dynlink", p) |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Name = obj.NAME_GOTREF |
| if p.From.Offset != 0 { |
| q := obj.Appendp(p, c.newprog) |
| q.As = AADD |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = p.From.Offset |
| q.To = p.To |
| p.From.Offset = 0 |
| } |
| } |
| if p.GetFrom3() != nil && p.GetFrom3().Name == obj.NAME_EXTERN { |
| c.ctxt.Diag("don't know how to handle %v with -dynlink", p) |
| } |
| var source *obj.Addr |
| // MOVx sym, Ry becomes MOVD sym@GOT, REGTMP; MOVx (REGTMP), Ry |
| // MOVx Ry, sym becomes MOVD sym@GOT, REGTMP; MOVD Ry, (REGTMP) |
| // An addition may be inserted between the two MOVs if there is an offset. |
| if p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() { |
| if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() { |
| c.ctxt.Diag("cannot handle NAME_EXTERN on both sides in %v with -dynlink", p) |
| } |
| source = &p.From |
| } else if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() { |
| source = &p.To |
| } else { |
| return |
| } |
| if p.As == obj.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP { |
| return |
| } |
| if source.Sym.Type == objabi.STLSBSS { |
| return |
| } |
| if source.Type != obj.TYPE_MEM { |
| c.ctxt.Diag("don't know how to handle %v with -dynlink", p) |
| } |
| p1 := obj.Appendp(p, c.newprog) |
| p2 := obj.Appendp(p1, c.newprog) |
| p1.As = AMOVD |
| p1.From.Type = obj.TYPE_MEM |
| p1.From.Sym = source.Sym |
| p1.From.Name = obj.NAME_GOTREF |
| p1.To.Type = obj.TYPE_REG |
| p1.To.Reg = REGTMP |
| |
| p2.As = p.As |
| p2.From = p.From |
| p2.To = p.To |
| if p.From.Name == obj.NAME_EXTERN { |
| p2.From.Reg = REGTMP |
| p2.From.Name = obj.NAME_NONE |
| p2.From.Sym = nil |
| } else if p.To.Name == obj.NAME_EXTERN { |
| p2.To.Reg = REGTMP |
| p2.To.Name = obj.NAME_NONE |
| p2.To.Sym = nil |
| } else { |
| return |
| } |
| obj.Nopout(p) |
| } |
| |
| func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { |
| if cursym.Func().Text == nil || cursym.Func().Text.Link == nil { |
| return |
| } |
| |
| c := ctxt7{ctxt: ctxt, newprog: newprog, cursym: cursym} |
| |
| p := c.cursym.Func().Text |
| textstksiz := p.To.Offset |
| if textstksiz == -8 { |
| // Historical way to mark NOFRAME. |
| p.From.Sym.Set(obj.AttrNoFrame, true) |
| textstksiz = 0 |
| } |
| if textstksiz < 0 { |
| c.ctxt.Diag("negative frame size %d - did you mean NOFRAME?", textstksiz) |
| } |
| if p.From.Sym.NoFrame() { |
| if textstksiz != 0 { |
| c.ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz) |
| } |
| } |
| |
| c.cursym.Func().Args = p.To.Val.(int32) |
| c.cursym.Func().Locals = int32(textstksiz) |
| |
| /* |
| * find leaf subroutines |
| */ |
| for p := c.cursym.Func().Text; p != nil; p = p.Link { |
| switch p.As { |
| case obj.ATEXT: |
| p.Mark |= LEAF |
| |
| case ABL, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| c.cursym.Func().Text.Mark &^= LEAF |
| } |
| } |
| |
| var q *obj.Prog |
| var q1 *obj.Prog |
| var retjmp *obj.LSym |
| for p := c.cursym.Func().Text; p != nil; p = p.Link { |
| o := p.As |
| switch o { |
| case obj.ATEXT: |
| c.cursym.Func().Text = p |
| c.autosize = int32(textstksiz) |
| |
| if p.Mark&LEAF != 0 && c.autosize == 0 { |
| // A leaf function with no locals has no frame. |
| p.From.Sym.Set(obj.AttrNoFrame, true) |
| } |
| |
| if !p.From.Sym.NoFrame() { |
| // If there is a stack frame at all, it includes |
| // space to save the LR. |
| c.autosize += 8 |
| } |
| |
| if c.autosize != 0 { |
| extrasize := int32(0) |
| if c.autosize%16 == 8 { |
| // Allocate extra 8 bytes on the frame top to save FP |
| extrasize = 8 |
| } else if c.autosize&(16-1) == 0 { |
| // Allocate extra 16 bytes to save FP for the old frame whose size is 8 mod 16 |
| extrasize = 16 |
| } else { |
| c.ctxt.Diag("%v: unaligned frame size %d - must be 16 aligned", p, c.autosize-8) |
| } |
| c.autosize += extrasize |
| c.cursym.Func().Locals += extrasize |
| |
| // low 32 bits for autosize |
| // high 32 bits for extrasize |
| p.To.Offset = int64(c.autosize) | int64(extrasize)<<32 |
| } else { |
| // NOFRAME |
| p.To.Offset = 0 |
| } |
| |
| if c.autosize == 0 && c.cursym.Func().Text.Mark&LEAF == 0 { |
| if c.ctxt.Debugvlog { |
| c.ctxt.Logf("save suppressed in: %s\n", c.cursym.Func().Text.From.Sym.Name) |
| } |
| c.cursym.Func().Text.Mark |= LEAF |
| } |
| |
| if cursym.Func().Text.Mark&LEAF != 0 { |
| cursym.Set(obj.AttrLeaf, true) |
| if p.From.Sym.NoFrame() { |
| break |
| } |
| } |
| |
| if p.Mark&LEAF != 0 && c.autosize < objabi.StackSmall { |
| // A leaf function with a small stack can be marked |
| // NOSPLIT, avoiding a stack check. |
| p.From.Sym.Set(obj.AttrNoSplit, true) |
| } |
| |
| if !p.From.Sym.NoSplit() { |
| p = c.stacksplit(p, c.autosize) // emit split check |
| } |
| |
| var prologueEnd *obj.Prog |
| |
| aoffset := c.autosize |
| if aoffset > 0xf0 { |
| // MOVD.W offset variant range is -0x100 to 0xf8, SP should be 16-byte aligned. |
| // so the maximum aoffset value is 0xf0. |
| aoffset = 0xf0 |
| } |
| |
| // Frame is non-empty. Make sure to save link register, even if |
| // it is a leaf function, so that traceback works. |
| q = p |
| if c.autosize > aoffset { |
| // Frame size is too large for a MOVD.W instruction. Store the frame pointer |
| // register and link register before decrementing SP, so if a signal comes |
| // during the execution of the function prologue, the traceback code will |
| // not see a half-updated stack frame. |
| |
| // SUB $autosize, RSP, R20 |
| q1 = obj.Appendp(q, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = ASUB |
| q1.From.Type = obj.TYPE_CONST |
| q1.From.Offset = int64(c.autosize) |
| q1.Reg = REGSP |
| q1.To.Type = obj.TYPE_REG |
| q1.To.Reg = REG_R20 |
| |
| prologueEnd = q1 |
| |
| // STP (R29, R30), -8(R20) |
| q1 = obj.Appendp(q1, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = ASTP |
| q1.From.Type = obj.TYPE_REGREG |
| q1.From.Reg = REGFP |
| q1.From.Offset = REGLINK |
| q1.To.Type = obj.TYPE_MEM |
| q1.To.Reg = REG_R20 |
| q1.To.Offset = -8 |
| |
| // This is not async preemptible, as if we open a frame |
| // at the current SP, it will clobber the saved LR. |
| q1 = c.ctxt.StartUnsafePoint(q1, c.newprog) |
| |
| // MOVD R20, RSP |
| q1 = obj.Appendp(q1, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = AMOVD |
| q1.From.Type = obj.TYPE_REG |
| q1.From.Reg = REG_R20 |
| q1.To.Type = obj.TYPE_REG |
| q1.To.Reg = REGSP |
| q1.Spadj = c.autosize |
| |
| q1 = c.ctxt.EndUnsafePoint(q1, c.newprog, -1) |
| |
| if buildcfg.GOOS == "ios" { |
| // iOS does not support SA_ONSTACK. We will run the signal handler |
| // on the G stack. If we write below SP, it may be clobbered by |
| // the signal handler. So we save FP and LR after decrementing SP. |
| // STP (R29, R30), -8(RSP) |
| q1 = obj.Appendp(q1, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = ASTP |
| q1.From.Type = obj.TYPE_REGREG |
| q1.From.Reg = REGFP |
| q1.From.Offset = REGLINK |
| q1.To.Type = obj.TYPE_MEM |
| q1.To.Reg = REGSP |
| q1.To.Offset = -8 |
| } |
| } else { |
| // small frame, update SP and save LR in a single MOVD.W instruction. |
| // So if a signal comes during the execution of the function prologue, |
| // the traceback code will not see a half-updated stack frame. |
| // Also, on Linux, in a cgo binary we may get a SIGSETXID signal |
| // early on before the signal stack is set, as glibc doesn't allow |
| // us to block SIGSETXID. So it is important that we don't write below |
| // the SP until the signal stack is set. |
| // Luckily, all the functions from thread entry to setting the signal |
| // stack have small frames. |
| q1 = obj.Appendp(q, c.newprog) |
| q1.As = AMOVD |
| q1.Pos = p.Pos |
| q1.From.Type = obj.TYPE_REG |
| q1.From.Reg = REGLINK |
| q1.To.Type = obj.TYPE_MEM |
| q1.Scond = C_XPRE |
| q1.To.Offset = int64(-aoffset) |
| q1.To.Reg = REGSP |
| q1.Spadj = aoffset |
| |
| prologueEnd = q1 |
| |
| // Frame pointer. |
| q1 = obj.Appendp(q1, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = AMOVD |
| q1.From.Type = obj.TYPE_REG |
| q1.From.Reg = REGFP |
| q1.To.Type = obj.TYPE_MEM |
| q1.To.Reg = REGSP |
| q1.To.Offset = -8 |
| } |
| |
| prologueEnd.Pos = prologueEnd.Pos.WithXlogue(src.PosPrologueEnd) |
| |
| q1 = obj.Appendp(q1, c.newprog) |
| q1.Pos = p.Pos |
| q1.As = ASUB |
| q1.From.Type = obj.TYPE_CONST |
| q1.From.Offset = 8 |
| q1.Reg = REGSP |
| q1.To.Type = obj.TYPE_REG |
| q1.To.Reg = REGFP |
| |
| if c.cursym.Func().Text.From.Sym.Wrapper() { |
| // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame |
| // |
| // MOV g_panic(g), RT1 |
| // CBNZ checkargp |
| // end: |
| // NOP |
| // ... function body ... |
| // checkargp: |
| // MOV panic_argp(RT1), RT2 |
| // ADD $(autosize+8), RSP, R20 |
| // CMP RT2, R20 |
| // BNE end |
| // ADD $8, RSP, R20 |
| // MOVD R20, panic_argp(RT1) |
| // B end |
| // |
| // The NOP is needed to give the jumps somewhere to land. |
| // It is a liblink NOP, not an ARM64 NOP: it encodes to 0 instruction bytes. |
| q = q1 |
| |
| // MOV g_panic(g), RT1 |
| q = obj.Appendp(q, c.newprog) |
| q.As = AMOVD |
| q.From.Type = obj.TYPE_MEM |
| q.From.Reg = REGG |
| q.From.Offset = 4 * int64(c.ctxt.Arch.PtrSize) // G.panic |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REGRT1 |
| |
| // CBNZ RT1, checkargp |
| cbnz := obj.Appendp(q, c.newprog) |
| cbnz.As = ACBNZ |
| cbnz.From.Type = obj.TYPE_REG |
| cbnz.From.Reg = REGRT1 |
| cbnz.To.Type = obj.TYPE_BRANCH |
| |
| // Empty branch target at the top of the function body |
| end := obj.Appendp(cbnz, c.newprog) |
| end.As = obj.ANOP |
| |
| // find the end of the function |
| var last *obj.Prog |
| for last = end; last.Link != nil; last = last.Link { |
| } |
| |
| // MOV panic_argp(RT1), RT2 |
| mov := obj.Appendp(last, c.newprog) |
| mov.As = AMOVD |
| mov.From.Type = obj.TYPE_MEM |
| mov.From.Reg = REGRT1 |
| mov.From.Offset = 0 // Panic.argp |
| mov.To.Type = obj.TYPE_REG |
| mov.To.Reg = REGRT2 |
| |
| // CBNZ branches to the MOV above |
| cbnz.To.SetTarget(mov) |
| |
| // ADD $(autosize+8), SP, R20 |
| q = obj.Appendp(mov, c.newprog) |
| q.As = AADD |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = int64(c.autosize) + 8 |
| q.Reg = REGSP |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REG_R20 |
| |
| // CMP RT2, R20 |
| q = obj.Appendp(q, c.newprog) |
| q.As = ACMP |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REGRT2 |
| q.Reg = REG_R20 |
| |
| // BNE end |
| q = obj.Appendp(q, c.newprog) |
| q.As = ABNE |
| q.To.Type = obj.TYPE_BRANCH |
| q.To.SetTarget(end) |
| |
| // ADD $8, SP, R20 |
| q = obj.Appendp(q, c.newprog) |
| q.As = AADD |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = 8 |
| q.Reg = REGSP |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REG_R20 |
| |
| // MOV R20, panic_argp(RT1) |
| q = obj.Appendp(q, c.newprog) |
| q.As = AMOVD |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REG_R20 |
| q.To.Type = obj.TYPE_MEM |
| q.To.Reg = REGRT1 |
| q.To.Offset = 0 // Panic.argp |
| |
| // B end |
| q = obj.Appendp(q, c.newprog) |
| q.As = AB |
| q.To.Type = obj.TYPE_BRANCH |
| q.To.SetTarget(end) |
| } |
| |
| case obj.ARET: |
| nocache(p) |
| if p.From.Type == obj.TYPE_CONST { |
| c.ctxt.Diag("using BECOME (%v) is not supported!", p) |
| break |
| } |
| |
| retjmp = p.To.Sym |
| p.To = obj.Addr{} |
| if c.cursym.Func().Text.Mark&LEAF != 0 { |
| if c.autosize != 0 { |
| p.As = AADD |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(c.autosize) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGSP |
| p.Spadj = -c.autosize |
| |
| // Frame pointer. |
| p = obj.Appendp(p, c.newprog) |
| p.As = ASUB |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 8 |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGFP |
| } |
| } else { |
| aoffset := c.autosize |
| // LDP -8(RSP), (R29, R30) |
| p.As = ALDP |
| p.From.Type = obj.TYPE_MEM |
| p.From.Offset = -8 |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REGREG |
| p.To.Reg = REGFP |
| p.To.Offset = REGLINK |
| |
| // ADD $aoffset, RSP, RSP |
| q = newprog() |
| q.As = AADD |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = int64(aoffset) |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REGSP |
| q.Spadj = -aoffset |
| q.Pos = p.Pos |
| q.Link = p.Link |
| p.Link = q |
| p = q |
| } |
| |
| // If enabled, this code emits 'MOV PC, R27' before every 'MOV LR, PC', |
| // so that if you are debugging a low-level crash where PC and LR are zero, |
| // you can look at R27 to see what jumped to the zero. |
| // This is useful when bringing up Go on a new system. |
| // (There is similar code in ../ppc64/obj9.go:/if.false.) |
| const debugRETZERO = false |
| if debugRETZERO { |
| if p.As != obj.ARET { |
| q = newprog() |
| q.Pos = p.Pos |
| q.Link = p.Link |
| p.Link = q |
| p = q |
| } |
| p.As = AADR |
| p.From.Type = obj.TYPE_BRANCH |
| p.From.Offset = 0 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGTMP |
| |
| } |
| |
| if p.As != obj.ARET { |
| q = newprog() |
| q.Pos = p.Pos |
| q.Link = p.Link |
| p.Link = q |
| p = q |
| } |
| |
| if retjmp != nil { // retjmp |
| p.As = AB |
| p.To.Type = obj.TYPE_BRANCH |
| p.To.Sym = retjmp |
| p.Spadj = +c.autosize |
| break |
| } |
| |
| p.As = obj.ARET |
| p.To.Type = obj.TYPE_MEM |
| p.To.Offset = 0 |
| p.To.Reg = REGLINK |
| p.Spadj = +c.autosize |
| |
| case AADD, ASUB: |
| if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST { |
| if p.As == AADD { |
| p.Spadj = int32(-p.From.Offset) |
| } else { |
| p.Spadj = int32(+p.From.Offset) |
| } |
| } |
| |
| case obj.AGETCALLERPC: |
| if cursym.Leaf() { |
| /* MOVD LR, Rd */ |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| } else { |
| /* MOVD (RSP), Rd */ |
| p.As = AMOVD |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGSP |
| } |
| |
| case obj.ADUFFCOPY: |
| // ADR ret_addr, R27 |
| // STP (FP, R27), -24(SP) |
| // SUB 24, SP, FP |
| // DUFFCOPY |
| // ret_addr: |
| // SUB 8, SP, FP |
| |
| q1 := p |
| // copy DUFFCOPY from q1 to q4 |
| q4 := obj.Appendp(p, c.newprog) |
| q4.Pos = p.Pos |
| q4.As = obj.ADUFFCOPY |
| q4.To = p.To |
| |
| q1.As = AADR |
| q1.From.Type = obj.TYPE_BRANCH |
| q1.To.Type = obj.TYPE_REG |
| q1.To.Reg = REG_R27 |
| |
| q2 := obj.Appendp(q1, c.newprog) |
| q2.Pos = p.Pos |
| q2.As = ASTP |
| q2.From.Type = obj.TYPE_REGREG |
| q2.From.Reg = REGFP |
| q2.From.Offset = int64(REG_R27) |
| q2.To.Type = obj.TYPE_MEM |
| q2.To.Reg = REGSP |
| q2.To.Offset = -24 |
| |
| // maintain FP for DUFFCOPY |
| q3 := obj.Appendp(q2, c.newprog) |
| q3.Pos = p.Pos |
| q3.As = ASUB |
| q3.From.Type = obj.TYPE_CONST |
| q3.From.Offset = 24 |
| q3.Reg = REGSP |
| q3.To.Type = obj.TYPE_REG |
| q3.To.Reg = REGFP |
| |
| q5 := obj.Appendp(q4, c.newprog) |
| q5.Pos = p.Pos |
| q5.As = ASUB |
| q5.From.Type = obj.TYPE_CONST |
| q5.From.Offset = 8 |
| q5.Reg = REGSP |
| q5.To.Type = obj.TYPE_REG |
| q5.To.Reg = REGFP |
| q1.From.SetTarget(q5) |
| p = q5 |
| |
| case obj.ADUFFZERO: |
| // ADR ret_addr, R27 |
| // STP (FP, R27), -24(SP) |
| // SUB 24, SP, FP |
| // DUFFZERO |
| // ret_addr: |
| // SUB 8, SP, FP |
| |
| q1 := p |
| // copy DUFFZERO from q1 to q4 |
| q4 := obj.Appendp(p, c.newprog) |
| q4.Pos = p.Pos |
| q4.As = obj.ADUFFZERO |
| q4.To = p.To |
| |
| q1.As = AADR |
| q1.From.Type = obj.TYPE_BRANCH |
| q1.To.Type = obj.TYPE_REG |
| q1.To.Reg = REG_R27 |
| |
| q2 := obj.Appendp(q1, c.newprog) |
| q2.Pos = p.Pos |
| q2.As = ASTP |
| q2.From.Type = obj.TYPE_REGREG |
| q2.From.Reg = REGFP |
| q2.From.Offset = int64(REG_R27) |
| q2.To.Type = obj.TYPE_MEM |
| q2.To.Reg = REGSP |
| q2.To.Offset = -24 |
| |
| // maintain FP for DUFFZERO |
| q3 := obj.Appendp(q2, c.newprog) |
| q3.Pos = p.Pos |
| q3.As = ASUB |
| q3.From.Type = obj.TYPE_CONST |
| q3.From.Offset = 24 |
| q3.Reg = REGSP |
| q3.To.Type = obj.TYPE_REG |
| q3.To.Reg = REGFP |
| |
| q5 := obj.Appendp(q4, c.newprog) |
| q5.Pos = p.Pos |
| q5.As = ASUB |
| q5.From.Type = obj.TYPE_CONST |
| q5.From.Offset = 8 |
| q5.Reg = REGSP |
| q5.To.Type = obj.TYPE_REG |
| q5.To.Reg = REGFP |
| q1.From.SetTarget(q5) |
| p = q5 |
| } |
| |
| if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.Spadj == 0 { |
| f := c.cursym.Func() |
| if f.FuncFlag&objabi.FuncFlag_SPWRITE == 0 { |
| c.cursym.Func().FuncFlag |= objabi.FuncFlag_SPWRITE |
| if ctxt.Debugvlog || !ctxt.IsAsm { |
| ctxt.Logf("auto-SPWRITE: %s %v\n", c.cursym.Name, p) |
| if !ctxt.IsAsm { |
| ctxt.Diag("invalid auto-SPWRITE in non-assembly") |
| ctxt.DiagFlush() |
| log.Fatalf("bad SPWRITE") |
| } |
| } |
| } |
| } |
| if p.From.Type == obj.TYPE_SHIFT && (p.To.Reg == REG_RSP || p.Reg == REG_RSP) { |
| offset := p.From.Offset |
| op := offset & (3 << 22) |
| if op != SHIFT_LL { |
| ctxt.Diag("illegal combination: %v", p) |
| } |
| r := (offset >> 16) & 31 |
| shift := (offset >> 10) & 63 |
| if shift > 4 { |
| // the shift amount is out of range, in order to avoid repeated error |
| // reportings, don't call ctxt.Diag, because asmout case 27 has the |
| // same check. |
| shift = 7 |
| } |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = int16(REG_LSL + r + (shift&7)<<5) |
| p.From.Offset = 0 |
| } |
| } |
| } |
| |
| func nocache(p *obj.Prog) { |
| p.Optab = 0 |
| p.From.Class = 0 |
| p.To.Class = 0 |
| } |
| |
| var unaryDst = map[obj.As]bool{ |
| AWORD: true, |
| ADWORD: true, |
| ABL: true, |
| AB: true, |
| ACLREX: true, |
| } |
| |
| var Linkarm64 = obj.LinkArch{ |
| Arch: sys.ArchARM64, |
| Init: buildop, |
| Preprocess: preprocess, |
| Assemble: span7, |
| Progedit: progedit, |
| UnaryDst: unaryDst, |
| DWARFRegisters: ARM64DWARFRegisters, |
| } |
