| // Copyright 2022 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 loong64 |
| |
| import ( |
| "cmd/internal/obj" |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "internal/abi" |
| "log" |
| "math" |
| ) |
| |
| func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) { |
| // Rewrite JMP/JAL to symbol as TYPE_BRANCH. |
| switch p.As { |
| case AJMP, |
| AJAL, |
| ARET, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| if p.To.Sym != nil { |
| p.To.Type = obj.TYPE_BRANCH |
| } |
| } |
| |
| // Rewrite float constants to values stored in memory. |
| switch p.As { |
| case AMOVF: |
| if p.From.Type == obj.TYPE_FCONST { |
| f32 := float32(p.From.Val.(float64)) |
| if math.Float32bits(f32) == 0 { |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGZERO |
| break |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = ctxt.Float32Sym(f32) |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| |
| case AMOVD: |
| if p.From.Type == obj.TYPE_FCONST { |
| f64 := p.From.Val.(float64) |
| if math.Float64bits(f64) == 0 { |
| p.As = AMOVV |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGZERO |
| break |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = ctxt.Float64Sym(f64) |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| } |
| |
| // Rewrite SUB constants into ADD. |
| switch p.As { |
| case ASUB: |
| if p.From.Type == obj.TYPE_CONST { |
| p.From.Offset = -p.From.Offset |
| p.As = AADD |
| } |
| |
| case ASUBU: |
| if p.From.Type == obj.TYPE_CONST { |
| p.From.Offset = -p.From.Offset |
| p.As = AADDU |
| } |
| |
| case ASUBV: |
| if p.From.Type == obj.TYPE_CONST { |
| p.From.Offset = -p.From.Offset |
| p.As = AADDV |
| } |
| |
| case ASUBVU: |
| if p.From.Type == obj.TYPE_CONST { |
| p.From.Offset = -p.From.Offset |
| p.As = AADDVU |
| } |
| } |
| |
| if ctxt.Flag_dynlink { |
| rewriteToUseGot(ctxt, p, newprog) |
| } |
| } |
| |
| func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) { |
| // ADUFFxxx $offset |
| // becomes |
| // MOVV runtime.duffxxx@GOT, REGTMP |
| // ADD $offset, REGTMP |
| // JAL REGTMP |
| if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO { |
| var sym *obj.LSym |
| if p.As == obj.ADUFFZERO { |
| sym = ctxt.Lookup("runtime.duffzero") |
| } else { |
| sym = ctxt.Lookup("runtime.duffcopy") |
| } |
| offset := p.To.Offset |
| p.As = AMOVV |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = sym |
| p.From.Name = obj.NAME_GOTREF |
| 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, newprog) |
| p1.As = AADDV |
| p1.From.Type = obj.TYPE_CONST |
| p1.From.Offset = offset |
| p1.To.Type = obj.TYPE_REG |
| p1.To.Reg = REGTMP |
| p2 := obj.Appendp(p1, newprog) |
| p2.As = AJAL |
| p2.To.Type = obj.TYPE_MEM |
| 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() { |
| // MOVV $sym, Rx becomes MOVV sym@GOT, Rx |
| // MOVV $sym+<off>, Rx becomes MOVV sym@GOT, Rx; ADD <off>, Rx |
| if p.As != AMOVV { |
| ctxt.Diag("do not know how to handle TYPE_ADDR in %v with -shared", p) |
| } |
| if p.To.Type != obj.TYPE_REG { |
| ctxt.Diag("do not know how to handle LEAQ-type insn to non-register in %v with -shared", p) |
| } |
| p.From.Type = obj.TYPE_MEM |
| p.From.Name = obj.NAME_GOTREF |
| if p.From.Offset != 0 { |
| q := obj.Appendp(p, newprog) |
| q.As = AADDV |
| 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 { |
| ctxt.Diag("don't know how to handle %v with -shared", p) |
| } |
| |
| var source *obj.Addr |
| // MOVx sym, Ry becomes MOVV sym@GOT, REGTMP; MOVx (REGTMP), Ry |
| // MOVx Ry, sym becomes MOVV sym@GOT, REGTMP; MOVx 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() { |
| ctxt.Diag("cannot handle NAME_EXTERN on both sides in %v with -shared", 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 { |
| ctxt.Diag("don't know how to handle %v with -shared", p) |
| } |
| p1 := obj.Appendp(p, newprog) |
| p2 := obj.Appendp(p1, newprog) |
| p1.As = AMOVV |
| 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) { |
| c := ctxt0{ctxt: ctxt, newprog: newprog, cursym: cursym} |
| |
| p := c.cursym.Func().Text |
| textstksiz := p.To.Offset |
| |
| 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 |
| * expand RET |
| */ |
| |
| for p := c.cursym.Func().Text; p != nil; p = p.Link { |
| switch p.As { |
| case obj.ATEXT: |
| p.Mark |= LABEL | LEAF | SYNC |
| if p.Link != nil { |
| p.Link.Mark |= LABEL |
| } |
| |
| case AMOVW, |
| AMOVV: |
| if p.To.Type == obj.TYPE_REG && p.To.Reg >= REG_SPECIAL { |
| p.Mark |= LABEL | SYNC |
| break |
| } |
| if p.From.Type == obj.TYPE_REG && p.From.Reg >= REG_SPECIAL { |
| p.Mark |= LABEL | SYNC |
| } |
| |
| case ASYSCALL, |
| AWORD: |
| p.Mark |= LABEL | SYNC |
| |
| case ANOR: |
| if p.To.Type == obj.TYPE_REG { |
| if p.To.Reg == REGZERO { |
| p.Mark |= LABEL | SYNC |
| } |
| } |
| |
| case AJAL, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| c.cursym.Func().Text.Mark &^= LEAF |
| fallthrough |
| |
| case AJMP, |
| ABEQ, |
| ABGEU, |
| ABLTU, |
| ABLTZ, |
| ABNE, |
| ABFPT, ABFPF: |
| p.Mark |= BRANCH |
| q1 := p.To.Target() |
| if q1 != nil { |
| for q1.As == obj.ANOP { |
| q1 = q1.Link |
| p.To.SetTarget(q1) |
| } |
| |
| if q1.Mark&LEAF == 0 { |
| q1.Mark |= LABEL |
| } |
| } |
| q1 = p.Link |
| if q1 != nil { |
| q1.Mark |= LABEL |
| } |
| |
| case ARET: |
| if p.Link != nil { |
| p.Link.Mark |= LABEL |
| } |
| } |
| } |
| |
| var mov, add obj.As |
| |
| add = AADDV |
| mov = AMOVV |
| |
| var q *obj.Prog |
| var q1 *obj.Prog |
| autosize := int32(0) |
| var p1 *obj.Prog |
| var p2 *obj.Prog |
| for p := c.cursym.Func().Text; p != nil; p = p.Link { |
| o := p.As |
| switch o { |
| case obj.ATEXT: |
| autosize = int32(textstksiz) |
| |
| if p.Mark&LEAF != 0 && 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. |
| autosize += int32(c.ctxt.Arch.FixedFrameSize) |
| } |
| |
| if autosize&4 != 0 { |
| autosize += 4 |
| } |
| |
| if autosize == 0 && c.cursym.Func().Text.Mark&LEAF == 0 { |
| if c.cursym.Func().Text.From.Sym.NoSplit() { |
| if ctxt.Debugvlog { |
| ctxt.Logf("save suppressed in: %s\n", c.cursym.Name) |
| } |
| |
| c.cursym.Func().Text.Mark |= LEAF |
| } |
| } |
| |
| p.To.Offset = int64(autosize) - ctxt.Arch.FixedFrameSize |
| |
| if c.cursym.Func().Text.Mark&LEAF != 0 { |
| c.cursym.Set(obj.AttrLeaf, true) |
| if p.From.Sym.NoFrame() { |
| break |
| } |
| } |
| |
| if !p.From.Sym.NoSplit() { |
| p = c.stacksplit(p, autosize) // emit split check |
| } |
| |
| q = p |
| |
| if autosize != 0 { |
| // Make sure to save link register for non-empty frame, even if |
| // it is a leaf function, so that traceback works. |
| // Store link register before decrement SP, so if a signal comes |
| // during the execution of the function prologue, the traceback |
| // code will not see a half-updated stack frame. |
| // This sequence is not async preemptible, as if we open a frame |
| // at the current SP, it will clobber the saved LR. |
| q = c.ctxt.StartUnsafePoint(q, c.newprog) |
| |
| q = obj.Appendp(q, newprog) |
| q.As = mov |
| q.Pos = p.Pos |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REGLINK |
| q.To.Type = obj.TYPE_MEM |
| q.To.Offset = int64(-autosize) |
| q.To.Reg = REGSP |
| |
| q = obj.Appendp(q, newprog) |
| q.As = add |
| q.Pos = p.Pos |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = int64(-autosize) |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REGSP |
| q.Spadj = +autosize |
| |
| q = c.ctxt.EndUnsafePoint(q, c.newprog, -1) |
| |
| // 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 a signal may land on the current stack and clobber |
| // the content below the SP. We store the LR again after the SP is |
| // decremented. |
| q = obj.Appendp(q, newprog) |
| q.As = mov |
| q.Pos = p.Pos |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REGLINK |
| q.To.Type = obj.TYPE_MEM |
| q.To.Offset = 0 |
| q.To.Reg = REGSP |
| } |
| |
| if c.cursym.Func().Text.From.Sym.Wrapper() && c.cursym.Func().Text.Mark&LEAF == 0 { |
| // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame |
| // |
| // MOV g_panic(g), R20 |
| // BEQ R20, end |
| // MOV panic_argp(R20), R24 |
| // ADD $(autosize+FIXED_FRAME), R3, R30 |
| // BNE R24, R30, end |
| // ADD $FIXED_FRAME, R3, R24 |
| // MOV R24, panic_argp(R20) |
| // end: |
| // NOP |
| // |
| // The NOP is needed to give the jumps somewhere to land. |
| // It is a liblink NOP, not a hardware NOP: it encodes to 0 instruction bytes. |
| // |
| // We don't generate this for leafs because that means the wrapped |
| // function was inlined into the wrapper. |
| |
| q = obj.Appendp(q, newprog) |
| |
| q.As = mov |
| 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 = REG_R20 |
| |
| q = obj.Appendp(q, newprog) |
| q.As = ABEQ |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REG_R20 |
| q.To.Type = obj.TYPE_BRANCH |
| q.Mark |= BRANCH |
| p1 = q |
| |
| q = obj.Appendp(q, newprog) |
| q.As = mov |
| q.From.Type = obj.TYPE_MEM |
| q.From.Reg = REG_R20 |
| q.From.Offset = 0 // Panic.argp |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REG_R24 |
| |
| q = obj.Appendp(q, newprog) |
| q.As = add |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = int64(autosize) + ctxt.Arch.FixedFrameSize |
| q.Reg = REGSP |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REG_R30 |
| |
| q = obj.Appendp(q, newprog) |
| q.As = ABNE |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REG_R24 |
| q.Reg = REG_R30 |
| q.To.Type = obj.TYPE_BRANCH |
| q.Mark |= BRANCH |
| p2 = q |
| |
| q = obj.Appendp(q, newprog) |
| q.As = add |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = ctxt.Arch.FixedFrameSize |
| q.Reg = REGSP |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REG_R24 |
| |
| q = obj.Appendp(q, newprog) |
| q.As = mov |
| q.From.Type = obj.TYPE_REG |
| q.From.Reg = REG_R24 |
| q.To.Type = obj.TYPE_MEM |
| q.To.Reg = REG_R20 |
| q.To.Offset = 0 // Panic.argp |
| |
| q = obj.Appendp(q, newprog) |
| |
| q.As = obj.ANOP |
| p1.To.SetTarget(q) |
| p2.To.SetTarget(q) |
| } |
| |
| case ARET: |
| if p.From.Type == obj.TYPE_CONST { |
| ctxt.Diag("using BECOME (%v) is not supported!", p) |
| break |
| } |
| |
| retSym := p.To.Sym |
| p.To.Name = obj.NAME_NONE // clear fields as we may modify p to other instruction |
| p.To.Sym = nil |
| |
| if c.cursym.Func().Text.Mark&LEAF != 0 { |
| if autosize == 0 { |
| p.As = AJMP |
| p.From = obj.Addr{} |
| if retSym != nil { // retjmp |
| p.To.Type = obj.TYPE_BRANCH |
| p.To.Name = obj.NAME_EXTERN |
| p.To.Sym = retSym |
| } else { |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REGLINK |
| p.To.Offset = 0 |
| } |
| p.Mark |= BRANCH |
| break |
| } |
| |
| p.As = add |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(autosize) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGSP |
| p.Spadj = -autosize |
| |
| q = c.newprog() |
| q.As = AJMP |
| q.Pos = p.Pos |
| if retSym != nil { // retjmp |
| q.To.Type = obj.TYPE_BRANCH |
| q.To.Name = obj.NAME_EXTERN |
| q.To.Sym = retSym |
| } else { |
| q.To.Type = obj.TYPE_MEM |
| q.To.Offset = 0 |
| q.To.Reg = REGLINK |
| } |
| q.Mark |= BRANCH |
| q.Spadj = +autosize |
| |
| q.Link = p.Link |
| p.Link = q |
| break |
| } |
| |
| p.As = mov |
| p.From.Type = obj.TYPE_MEM |
| p.From.Offset = 0 |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGLINK |
| |
| if autosize != 0 { |
| q = c.newprog() |
| q.As = add |
| q.Pos = p.Pos |
| q.From.Type = obj.TYPE_CONST |
| q.From.Offset = int64(autosize) |
| q.To.Type = obj.TYPE_REG |
| q.To.Reg = REGSP |
| q.Spadj = -autosize |
| |
| q.Link = p.Link |
| p.Link = q |
| } |
| |
| q1 = c.newprog() |
| q1.As = AJMP |
| q1.Pos = p.Pos |
| if retSym != nil { // retjmp |
| q1.To.Type = obj.TYPE_BRANCH |
| q1.To.Name = obj.NAME_EXTERN |
| q1.To.Sym = retSym |
| } else { |
| q1.To.Type = obj.TYPE_MEM |
| q1.To.Offset = 0 |
| q1.To.Reg = REGLINK |
| } |
| q1.Mark |= BRANCH |
| q1.Spadj = +autosize |
| |
| q1.Link = q.Link |
| q.Link = q1 |
| |
| case AADD, |
| AADDU, |
| AADDV, |
| AADDVU: |
| if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST { |
| p.Spadj = int32(-p.From.Offset) |
| } |
| |
| case obj.AGETCALLERPC: |
| if cursym.Leaf() { |
| // MOV LR, Rd |
| p.As = mov |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| } else { |
| // MOV (RSP), Rd |
| p.As = mov |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGSP |
| } |
| } |
| |
| if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.Spadj == 0 { |
| f := c.cursym.Func() |
| if f.FuncFlag&abi.FuncFlagSPWrite == 0 { |
| c.cursym.Func().FuncFlag |= abi.FuncFlagSPWrite |
| 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") |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| func (c *ctxt0) stacksplit(p *obj.Prog, framesize int32) *obj.Prog { |
| var mov, add obj.As |
| |
| add = AADDV |
| mov = AMOVV |
| if c.ctxt.Flag_maymorestack != "" { |
| // Save LR and REGCTXT. |
| frameSize := 2 * c.ctxt.Arch.PtrSize |
| |
| p = c.ctxt.StartUnsafePoint(p, c.newprog) |
| |
| // Spill Arguments. This has to happen before we open |
| // any more frame space. |
| p = c.cursym.Func().SpillRegisterArgs(p, c.newprog) |
| |
| // MOV REGLINK, -8/-16(SP) |
| p = obj.Appendp(p, c.newprog) |
| p.As = mov |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| p.To.Type = obj.TYPE_MEM |
| p.To.Offset = int64(-frameSize) |
| p.To.Reg = REGSP |
| |
| // MOV REGCTXT, -4/-8(SP) |
| p = obj.Appendp(p, c.newprog) |
| p.As = mov |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGCTXT |
| p.To.Type = obj.TYPE_MEM |
| p.To.Offset = -int64(c.ctxt.Arch.PtrSize) |
| p.To.Reg = REGSP |
| |
| // ADD $-8/$-16, SP |
| p = obj.Appendp(p, c.newprog) |
| p.As = add |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(-frameSize) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGSP |
| p.Spadj = int32(frameSize) |
| |
| // JAL maymorestack |
| p = obj.Appendp(p, c.newprog) |
| p.As = AJAL |
| p.To.Type = obj.TYPE_BRANCH |
| // See ../x86/obj6.go |
| p.To.Sym = c.ctxt.LookupABI(c.ctxt.Flag_maymorestack, c.cursym.ABI()) |
| p.Mark |= BRANCH |
| |
| // Restore LR and REGCTXT. |
| |
| // MOV 0(SP), REGLINK |
| p = obj.Appendp(p, c.newprog) |
| p.As = mov |
| p.From.Type = obj.TYPE_MEM |
| p.From.Offset = 0 |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGLINK |
| |
| // MOV 4/8(SP), REGCTXT |
| p = obj.Appendp(p, c.newprog) |
| p.As = mov |
| p.From.Type = obj.TYPE_MEM |
| p.From.Offset = int64(c.ctxt.Arch.PtrSize) |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGCTXT |
| |
| // ADD $8/$16, SP |
| p = obj.Appendp(p, c.newprog) |
| p.As = add |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(frameSize) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGSP |
| p.Spadj = int32(-frameSize) |
| |
| // Unspill arguments |
| p = c.cursym.Func().UnspillRegisterArgs(p, c.newprog) |
| p = c.ctxt.EndUnsafePoint(p, c.newprog, -1) |
| } |
| |
| // Jump back to here after morestack returns. |
| startPred := p |
| |
| // MOV g_stackguard(g), R20 |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = mov |
| 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 = REG_R20 |
| |
| // 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) |
| |
| var q *obj.Prog |
| if framesize <= abi.StackSmall { |
| // small stack: SP < stackguard |
| // AGTU SP, stackguard, R20 |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = ASGTU |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGSP |
| p.Reg = REG_R20 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R20 |
| } else { |
| // large stack: SP-framesize < stackguard-StackSmall |
| offset := int64(framesize) - abi.StackSmall |
| if framesize > abi.StackBig { |
| // 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. |
| // |
| // SGTU $(framesize-StackSmall), SP, R24 |
| // BNE R24, label-of-call-to-morestack |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ASGTU |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = offset |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R24 |
| |
| p = obj.Appendp(p, c.newprog) |
| q = p |
| p.As = ABNE |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R24 |
| p.To.Type = obj.TYPE_BRANCH |
| p.Mark |= BRANCH |
| } |
| |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = add |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = -offset |
| p.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R24 |
| |
| p = obj.Appendp(p, c.newprog) |
| p.As = ASGTU |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R24 |
| p.Reg = REG_R20 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R20 |
| } |
| |
| // q1: BNE R20, done |
| p = obj.Appendp(p, c.newprog) |
| q1 := p |
| |
| p.As = ABNE |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R20 |
| p.To.Type = obj.TYPE_BRANCH |
| p.Mark |= BRANCH |
| |
| // MOV LINK, R31 |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = mov |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R31 |
| if q != nil { |
| q.To.SetTarget(p) |
| p.Mark |= LABEL |
| } |
| |
| p = c.ctxt.EmitEntryStackMap(c.cursym, p, c.newprog) |
| |
| // Spill the register args that could be clobbered by the |
| // morestack code |
| p = c.cursym.Func().SpillRegisterArgs(p, c.newprog) |
| |
| // JAL runtime.morestack(SB) |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = AJAL |
| p.To.Type = obj.TYPE_BRANCH |
| if c.cursym.CFunc() { |
| p.To.Sym = c.ctxt.Lookup("runtime.morestackc") |
| } else if !c.cursym.Func().Text.From.Sym.NeedCtxt() { |
| p.To.Sym = c.ctxt.Lookup("runtime.morestack_noctxt") |
| } else { |
| p.To.Sym = c.ctxt.Lookup("runtime.morestack") |
| } |
| p.Mark |= BRANCH |
| |
| p = c.cursym.Func().UnspillRegisterArgs(p, c.newprog) |
| p = c.ctxt.EndUnsafePoint(p, c.newprog, -1) |
| |
| // JMP start |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = AJMP |
| p.To.Type = obj.TYPE_BRANCH |
| p.To.SetTarget(startPred.Link) |
| startPred.Link.Mark |= LABEL |
| p.Mark |= BRANCH |
| |
| // placeholder for q1's jump target |
| p = obj.Appendp(p, c.newprog) |
| |
| p.As = obj.ANOP // zero-width place holder |
| q1.To.SetTarget(p) |
| |
| return p |
| } |
| |
| func (c *ctxt0) addnop(p *obj.Prog) { |
| q := c.newprog() |
| q.As = ANOOP |
| q.Pos = p.Pos |
| q.Link = p.Link |
| p.Link = q |
| } |
| |
| var Linkloong64 = obj.LinkArch{ |
| Arch: sys.ArchLoong64, |
| Init: buildop, |
| Preprocess: preprocess, |
| Assemble: span0, |
| Progedit: progedit, |
| DWARFRegisters: LOONG64DWARFRegisters, |
| } |
