diff options
Diffstat (limited to 'src/cmd/internal/obj/s390x/objz.go')
| -rw-r--r-- | src/cmd/internal/obj/s390x/objz.go | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/s390x/objz.go b/src/cmd/internal/obj/s390x/objz.go new file mode 100644 index 0000000..4e84756 --- /dev/null +++ b/src/cmd/internal/obj/s390x/objz.go @@ -0,0 +1,802 @@ +// Based on cmd/internal/obj/ppc64/obj9.go. +// +// 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 © 2000-2008 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 © 2000-2008 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 s390x + +import ( + "cmd/internal/obj" + "cmd/internal/objabi" + "cmd/internal/sys" + "log" + "math" +) + +func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) { + p.From.Class = 0 + p.To.Class = 0 + + c := ctxtz{ctxt: ctxt, newprog: newprog} + + // Rewrite BR/BL to symbol as TYPE_BRANCH. + switch p.As { + case ABR, ABL, obj.ARET, obj.ADUFFZERO, obj.ADUFFCOPY: + if p.To.Sym != nil { + p.To.Type = obj.TYPE_BRANCH + } + } + + // Rewrite float constants to values stored in memory unless they are +0. + switch p.As { + case AFMOVS: + if p.From.Type == obj.TYPE_FCONST { + f32 := float32(p.From.Val.(float64)) + if math.Float32bits(f32) == 0 { // +0 + break + } + p.From.Type = obj.TYPE_MEM + p.From.Sym = 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 math.Float64bits(f64) == 0 { // +0 + break + } + p.From.Type = obj.TYPE_MEM + p.From.Sym = ctxt.Float64Sym(f64) + p.From.Name = obj.NAME_EXTERN + p.From.Offset = 0 + } + + // put constants not loadable by LOAD IMMEDIATE into memory + case AMOVD: + if p.From.Type == obj.TYPE_CONST { + val := p.From.Offset + if int64(int32(val)) != val && + int64(uint32(val)) != val && + int64(uint64(val)&(0xffffffff<<32)) != val { + p.From.Type = obj.TYPE_MEM + p.From.Sym = ctxt.Int64Sym(p.From.Offset) + p.From.Name = obj.NAME_EXTERN + p.From.Offset = 0 + } + } + } + + // Rewrite SUB constants into ADD. + switch p.As { + case ASUBC: + if p.From.Type == obj.TYPE_CONST && isint32(-p.From.Offset) { + p.From.Offset = -p.From.Offset + p.As = AADDC + } + + case ASUB: + if p.From.Type == obj.TYPE_CONST && isint32(-p.From.Offset) { + p.From.Offset = -p.From.Offset + p.As = AADD + } + } + + if c.ctxt.Flag_dynlink { + c.rewriteToUseGot(p) + } +} + +// Rewrite p, if necessary, to access global data via the global offset table. +func (c *ctxtz) rewriteToUseGot(p *obj.Prog) { + // At the moment EXRL instructions are not emitted by the compiler and only reference local symbols in + // assembly code. + if p.As == AEXRL { + return + } + + // 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. + // Rewrites must not clobber flags and therefore cannot use the + // ADD instruction. + 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 or REGTMP2; MOVD $<off>(Rx or REGTMP2), Rx + if p.To.Type != obj.TYPE_REG || p.As != AMOVD { + c.ctxt.Diag("do not know how to handle LEA-type insn to non-register in %v with -dynlink", p) + } + p.From.Type = obj.TYPE_MEM + p.From.Name = obj.NAME_GOTREF + q := p + if p.From.Offset != 0 { + target := p.To.Reg + if target == REG_R0 { + // Cannot use R0 as input to address calculation. + // REGTMP might be used by the assembler. + p.To.Reg = REGTMP2 + } + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_ADDR + q.From.Offset = p.From.Offset + q.From.Reg = p.To.Reg + q.To.Type = obj.TYPE_REG + q.To.Reg = target + 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 + // MOVD sym, Ry becomes MOVD sym@GOT, REGTMP2; MOVD (REGTMP2), Ry + // MOVD Ry, sym becomes MOVD sym@GOT, REGTMP2; MOVD Ry, (REGTMP2) + // 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 = REGTMP2 + + p2.As = p.As + p2.From = p.From + p2.To = p.To + if p.From.Name == obj.NAME_EXTERN { + p2.From.Reg = REGTMP2 + p2.From.Name = obj.NAME_NONE + p2.From.Sym = nil + } else if p.To.Name == obj.NAME_EXTERN { + p2.To.Reg = REGTMP2 + 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) { + // TODO(minux): add morestack short-cuts with small fixed frame-size. + if cursym.Func().Text == nil || cursym.Func().Text.Link == nil { + return + } + + c := ctxtz{ctxt: ctxt, cursym: cursym, newprog: newprog} + + p := c.cursym.Func().Text + textstksiz := p.To.Offset + if textstksiz == -8 { + // Compatibility hack. + p.From.Sym.Set(obj.AttrNoFrame, true) + textstksiz = 0 + } + if textstksiz%8 != 0 { + c.ctxt.Diag("frame size %d not a multiple of 8", 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 + * strip NOPs + * expand RET + */ + + var q *obj.Prog + for p := c.cursym.Func().Text; p != nil; p = p.Link { + switch p.As { + case obj.ATEXT: + q = p + p.Mark |= LEAF + + case ABL, ABCL: + q = p + c.cursym.Func().Text.Mark &^= LEAF + fallthrough + + case ABC, + ABRC, + ABEQ, + ABGE, + ABGT, + ABLE, + ABLT, + ABLEU, + ABLTU, + ABNE, + ABR, + ABVC, + ABVS, + ACRJ, + ACGRJ, + ACLRJ, + ACLGRJ, + ACIJ, + ACGIJ, + ACLIJ, + ACLGIJ, + ACMPBEQ, + ACMPBGE, + ACMPBGT, + ACMPBLE, + ACMPBLT, + ACMPBNE, + ACMPUBEQ, + ACMPUBGE, + ACMPUBGT, + ACMPUBLE, + ACMPUBLT, + ACMPUBNE: + q = p + p.Mark |= BRANCH + + default: + q = p + } + } + + autosize := int32(0) + var pLast *obj.Prog + var pPre *obj.Prog + var pPreempt *obj.Prog + var pCheck *obj.Prog + wasSplit := false + for p := c.cursym.Func().Text; p != nil; p = p.Link { + pLast = p + switch p.As { + 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 p.Mark&LEAF != 0 && 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) + } + + p.To.Offset = int64(autosize) + + q := p + + if !p.From.Sym.NoSplit() { + p, pPreempt, pCheck = c.stacksplitPre(p, autosize) // emit pre part of split check + pPre = p + p = c.ctxt.EndUnsafePoint(p, c.newprog, -1) + wasSplit = true //need post part of split + } + + 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 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. + // 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(p, c.newprog) + + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_LR + q.To.Type = obj.TYPE_MEM + q.To.Reg = REGSP + q.To.Offset = int64(-autosize) + + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_ADDR + q.From.Offset = int64(-autosize) + q.From.Reg = REGSP // not actually needed - REGSP is assumed if no reg is provided + 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, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_LR + q.To.Type = obj.TYPE_MEM + q.To.Reg = REGSP + q.To.Offset = 0 + } else if c.cursym.Func().Text.Mark&LEAF == 0 { + // A very few functions that do not return to their caller + // (e.g. gogo) are not identified as leaves but still have + // no frame. + c.cursym.Func().Text.Mark |= LEAF + } + + if c.cursym.Func().Text.Mark&LEAF != 0 { + c.cursym.Set(obj.AttrLeaf, true) + break + } + + if c.cursym.Func().Text.From.Sym.Wrapper() { + // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame + // + // MOVD g_panic(g), R3 + // CMP R3, $0 + // BEQ end + // MOVD panic_argp(R3), R4 + // ADD $(autosize+8), R1, R5 + // CMP R4, R5 + // BNE end + // ADD $8, R1, R6 + // MOVD R6, panic_argp(R3) + // end: + // NOP + // + // The NOP is needed to give the jumps somewhere to land. + // It is a liblink NOP, not a s390x NOP: it encodes to 0 instruction bytes. + + 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 = REG_R3 + + q = obj.Appendp(q, c.newprog) + q.As = ACMP + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R3 + q.To.Type = obj.TYPE_CONST + q.To.Offset = 0 + + q = obj.Appendp(q, c.newprog) + q.As = ABEQ + q.To.Type = obj.TYPE_BRANCH + p1 := q + + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_MEM + q.From.Reg = REG_R3 + q.From.Offset = 0 // Panic.argp + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R4 + + q = obj.Appendp(q, c.newprog) + q.As = AADD + q.From.Type = obj.TYPE_CONST + q.From.Offset = int64(autosize) + c.ctxt.Arch.FixedFrameSize + q.Reg = REGSP + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R5 + + q = obj.Appendp(q, c.newprog) + q.As = ACMP + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R4 + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R5 + + q = obj.Appendp(q, c.newprog) + q.As = ABNE + q.To.Type = obj.TYPE_BRANCH + p2 := q + + q = obj.Appendp(q, c.newprog) + q.As = AADD + q.From.Type = obj.TYPE_CONST + q.From.Offset = c.ctxt.Arch.FixedFrameSize + q.Reg = REGSP + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R6 + + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R6 + q.To.Type = obj.TYPE_MEM + q.To.Reg = REG_R3 + q.To.Offset = 0 // Panic.argp + + q = obj.Appendp(q, c.newprog) + + q.As = obj.ANOP + p1.To.SetTarget(q) + p2.To.SetTarget(q) + } + + case obj.ARET: + retTarget := p.To.Sym + + if c.cursym.Func().Text.Mark&LEAF != 0 { + if autosize == 0 { + p.As = ABR + p.From = obj.Addr{} + if retTarget == nil { + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_LR + } else { + p.To.Type = obj.TYPE_BRANCH + p.To.Sym = retTarget + } + p.Mark |= BRANCH + break + } + + p.As = AADD + 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 = obj.Appendp(p, c.newprog) + q.As = ABR + q.From = obj.Addr{} + if retTarget == nil { + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_LR + } else { + q.To.Type = obj.TYPE_BRANCH + q.To.Sym = retTarget + } + q.Mark |= BRANCH + q.Spadj = autosize + break + } + + p.As = AMOVD + p.From.Type = obj.TYPE_MEM + p.From.Reg = REGSP + p.From.Offset = 0 + p.To = obj.Addr{ + Type: obj.TYPE_REG, + Reg: REG_LR, + } + + q = p + + if autosize != 0 { + q = obj.Appendp(q, c.newprog) + q.As = AADD + 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 = obj.Appendp(q, c.newprog) + q.As = ABR + q.From = obj.Addr{} + if retTarget == nil { + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_LR + } else { + q.To.Type = obj.TYPE_BRANCH + q.To.Sym = retTarget + } + q.Mark |= BRANCH + q.Spadj = autosize + + case AADD: + 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() { + /* MOVD LR, Rd */ + p.As = AMOVD + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_LR + } else { + /* MOVD (RSP), Rd */ + p.As = AMOVD + 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&objabi.FuncFlag_SPWRITE == 0 { + c.cursym.Func().FuncFlag |= objabi.FuncFlag_SPWRITE + if ctxt.Debugvlog || !ctxt.IsAsm { + ctxt.Logf("auto-SPWRITE: %s\n", c.cursym.Name) + if !ctxt.IsAsm { + ctxt.Diag("invalid auto-SPWRITE in non-assembly") + ctxt.DiagFlush() + log.Fatalf("bad SPWRITE") + } + } + } + } + } + if wasSplit { + c.stacksplitPost(pLast, pPre, pPreempt, pCheck, autosize) // emit post part of split check + } +} + +// stacksplitPre generates the function stack check prologue following +// Prog p (which should be the TEXT Prog). It returns one or two +// branch Progs that must be patched to jump to the morestack epilogue, +// and the Prog that starts the morestack check. +func (c *ctxtz) stacksplitPre(p *obj.Prog, framesize int32) (pPre, pPreempt, pCheck *obj.Prog) { + if c.ctxt.Flag_maymorestack != "" { + // Save LR and REGCTXT + const frameSize = 16 + p = c.ctxt.StartUnsafePoint(p, c.newprog) + // MOVD LR, -16(SP) + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR} + p.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REGSP, Offset: -frameSize} + // MOVD $-16(SP), SP + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_ADDR, Offset: -frameSize, Reg: REGSP} + p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REGSP} + p.Spadj = frameSize + // MOVD REGCTXT, 8(SP) + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REGCTXT} + p.To = obj.Addr{Type: obj.TYPE_MEM, Reg: REGSP, Offset: 8} + + // BL maymorestack + p = obj.Appendp(p, c.newprog) + p.As = ABL + // See ../x86/obj6.go + sym := c.ctxt.LookupABI(c.ctxt.Flag_maymorestack, c.cursym.ABI()) + p.To = obj.Addr{Type: obj.TYPE_BRANCH, Sym: sym} + + // Restore LR and REGCTXT + + // MOVD REGCTXT, 8(SP) + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REGSP, Offset: 8} + p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REGCTXT} + // MOVD (SP), LR + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_MEM, Reg: REGSP, Offset: 0} + p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR} + // MOVD $16(SP), SP + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From = obj.Addr{Type: obj.TYPE_CONST, Reg: REGSP, Offset: frameSize} + p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REGSP} + p.Spadj = -frameSize + + p = c.ctxt.EndUnsafePoint(p, c.newprog, -1) + } + + // MOVD g_stackguard(g), R3 + p = obj.Appendp(p, c.newprog) + // Jump back to here after morestack returns. + pCheck = p + + 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 = REG_R3 + + // 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) + + if framesize <= objabi.StackSmall { + // small stack: SP < stackguard + // CMPUBGE stackguard, SP, label-of-call-to-morestack + + p = obj.Appendp(p, c.newprog) + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R3 + p.Reg = REGSP + p.As = ACMPUBGE + p.To.Type = obj.TYPE_BRANCH + + return p, nil, pCheck + } + + // large stack: SP-framesize < stackguard-StackSmall + + offset := int64(framesize) - objabi.StackSmall + if framesize > objabi.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. + // + // MOVD $(framesize-StackSmall), R4 + // CMPUBLT SP, R4, label-of-call-to-morestack + + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From.Type = obj.TYPE_CONST + p.From.Offset = offset + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R4 + + p = obj.Appendp(p, c.newprog) + pPreempt = p + p.As = ACMPUBLT + p.From.Type = obj.TYPE_REG + p.From.Reg = REGSP + p.Reg = REG_R4 + p.To.Type = obj.TYPE_BRANCH + } + + // Check against the stack guard. We've ensured this won't underflow. + // ADD $-(framesize-StackSmall), SP, R4 + // CMPUBGE stackguard, R4, label-of-call-to-morestack + p = obj.Appendp(p, c.newprog) + p.As = AADD + p.From.Type = obj.TYPE_CONST + p.From.Offset = -offset + p.Reg = REGSP + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R4 + + p = obj.Appendp(p, c.newprog) + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R3 + p.Reg = REG_R4 + p.As = ACMPUBGE + p.To.Type = obj.TYPE_BRANCH + + return p, pPreempt, pCheck +} + +// stacksplitPost generates the function epilogue that calls morestack +// and returns the new last instruction in the function. +// +// p is the last Prog in the function. pPre and pPreempt, if non-nil, +// are the instructions that branch to the epilogue. This will fill in +// their branch targets. pCheck is the Prog that begins the stack check. +func (c *ctxtz) stacksplitPost(p *obj.Prog, pPre, pPreempt, pCheck *obj.Prog, framesize int32) *obj.Prog { + // 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(p, 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) + + // MOVD LR, R5 + p = obj.Appendp(pcdata, c.newprog) + pPre.To.SetTarget(p) + p.As = AMOVD + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_LR + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R5 + if pPreempt != nil { + pPreempt.To.SetTarget(p) + } + + // BL runtime.morestack(SB) + p = obj.Appendp(p, c.newprog) + + p.As = ABL + 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 = c.ctxt.EndUnsafePoint(p, c.newprog, -1) + + // BR pCheck + p = obj.Appendp(p, c.newprog) + + p.As = ABR + p.To.Type = obj.TYPE_BRANCH + p.To.SetTarget(pCheck) + return p +} + +var unaryDst = map[obj.As]bool{ + ASTCK: true, + ASTCKC: true, + ASTCKE: true, + ASTCKF: true, + ANEG: true, + ANEGW: true, + AVONE: true, + AVZERO: true, +} + +var Links390x = obj.LinkArch{ + Arch: sys.ArchS390X, + Init: buildop, + Preprocess: preprocess, + Assemble: spanz, + Progedit: progedit, + UnaryDst: unaryDst, + DWARFRegisters: S390XDWARFRegisters, +} |