diff options
Diffstat (limited to 'vendor/github.com/twitchyliquid64/golang-asm/obj/arm64/obj7.go')
-rw-r--r-- | vendor/github.com/twitchyliquid64/golang-asm/obj/arm64/obj7.go | 998 |
1 files changed, 998 insertions, 0 deletions
diff --git a/vendor/github.com/twitchyliquid64/golang-asm/obj/arm64/obj7.go b/vendor/github.com/twitchyliquid64/golang-asm/obj/arm64/obj7.go new file mode 100644 index 000000000..d2d935bd4 --- /dev/null +++ b/vendor/github.com/twitchyliquid64/golang-asm/obj/arm64/obj7.go @@ -0,0 +1,998 @@ +// 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 ( + "github.com/twitchyliquid64/golang-asm/obj" + "github.com/twitchyliquid64/golang-asm/objabi" + "github.com/twitchyliquid64/golang-asm/src" + "github.com/twitchyliquid64/golang-asm/sys" + "math" +) + +var complements = []obj.As{ + AADD: ASUB, + AADDW: ASUBW, + ASUB: AADD, + ASUBW: AADDW, + ACMP: ACMN, + ACMPW: ACMNW, + ACMN: ACMP, + ACMNW: ACMPW, +} + +func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog { + // MOV g_stackguard(g), R1 + 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 = REG_R1 + + // 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 + // MOV SP, R2 + // CMP stackguard, R2 + p = obj.Appendp(p, c.newprog) + + p.As = AMOVD + p.From.Type = obj.TYPE_REG + p.From.Reg = REGSP + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R2 + + p = obj.Appendp(p, c.newprog) + p.As = ACMP + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R1 + p.Reg = REG_R2 + } else if framesize <= objabi.StackBig { + // large stack: SP-framesize < stackguard-StackSmall + // SUB $(framesize-StackSmall), SP, R2 + // CMP stackguard, R2 + 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 = REG_R2 + + p = obj.Appendp(p, c.newprog) + p.As = ACMP + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R1 + p.Reg = REG_R2 + } else { + // Such a large stack we need to protect against wraparound + // if SP is close to zero. + // SP-stackguard+StackGuard < framesize + (StackGuard-StackSmall) + // The +StackGuard on both sides is required to keep the left side positive: + // SP is allowed to be slightly below stackguard. See stack.h. + // CMP $StackPreempt, R1 + // BEQ label_of_call_to_morestack + // ADD $StackGuard, SP, R2 + // SUB R1, R2 + // MOV $(framesize+(StackGuard-StackSmall)), R3 + // CMP R3, R2 + p = obj.Appendp(p, c.newprog) + + p.As = ACMP + p.From.Type = obj.TYPE_CONST + p.From.Offset = objabi.StackPreempt + p.Reg = REG_R1 + + p = obj.Appendp(p, c.newprog) + q = p + p.As = ABEQ + p.To.Type = obj.TYPE_BRANCH + + p = obj.Appendp(p, c.newprog) + p.As = AADD + p.From.Type = obj.TYPE_CONST + p.From.Offset = int64(objabi.StackGuard) + p.Reg = REGSP + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R2 + + p = obj.Appendp(p, c.newprog) + p.As = ASUB + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R1 + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R2 + + p = obj.Appendp(p, c.newprog) + p.As = AMOVD + p.From.Type = obj.TYPE_CONST + p.From.Offset = int64(framesize) + (int64(objabi.StackGuard) - objabi.StackSmall) + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R3 + + p = obj.Appendp(p, c.newprog) + p.As = ACMP + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R3 + p.Reg = REG_R2 + } + + // 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) + + // MOV LR, R3 + movlr := obj.Appendp(pcdata, 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 + if q != nil { + q.To.SetTarget(movlr) + } + bls.To.SetTarget(movlr) + + 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) + + pcdata = c.ctxt.EndUnsafePoint(call, c.newprog, -1) + + // B start + jmp := obj.Appendp(pcdata, c.newprog) + jmp.As = AB + jmp.To.Type = obj.TYPE_BRANCH + jmp.To.SetTarget(c.cursym.Func.Text.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 { + 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] + } + } + + // For 32-bit logical instruction with constant, + // rewrite the high 32-bit to be a repetition of + // the low 32-bit, so that the BITCON test can be + // shared for both 32-bit and 64-bit. 32-bit ops + // will zero the high 32-bit of the destination + // register anyway. + if isANDWop(p.As) && p.From.Type == obj.TYPE_CONST { + v := p.From.Offset & 0xffffffff + p.From.Offset = v | v<<32 + } + + 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.Lookup("runtime.duffzero") + } else { + sym = c.ctxt.Lookup("runtime.duffcopy") + } + 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.From.Sym.NoSplit() { + p = c.stacksplit(p, c.autosize) // emit split check + } + + var prologueEnd *obj.Prog + + aoffset := c.autosize + if aoffset > 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 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(q, c.newprog) + + q = obj.Appendp(q, c.newprog) + q.Pos = p.Pos + q.As = ASUB + q.From.Type = obj.TYPE_CONST + q.From.Offset = int64(c.autosize) + q.Reg = REGSP + q.To.Type = obj.TYPE_REG + q.To.Reg = REGTMP + + prologueEnd = q + + q = obj.Appendp(q, c.newprog) + q.Pos = p.Pos + q.As = AMOVD + q.From.Type = obj.TYPE_REG + q.From.Reg = REGLINK + q.To.Type = obj.TYPE_MEM + q.To.Reg = REGTMP + + q1 = obj.Appendp(q, c.newprog) + q1.Pos = p.Pos + q1.As = AMOVD + q1.From.Type = obj.TYPE_REG + q1.From.Reg = REGTMP + q1.To.Type = obj.TYPE_REG + q1.To.Reg = REGSP + q1.Spadj = c.autosize + + if c.ctxt.Headtype == objabi.Hdarwin { + // 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 LR after decrementing SP. + q1 = obj.Appendp(q1, c.newprog) + q1.Pos = p.Pos + q1.As = AMOVD + q1.From.Type = obj.TYPE_REG + q1.From.Reg = REGLINK + q1.To.Type = obj.TYPE_MEM + q1.To.Reg = REGSP + } + + q1 = c.ctxt.EndUnsafePoint(q1, c.newprog, -1) + } else { + // small frame, update SP and save LR in a single MOVD.W instruction + 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 + } + + prologueEnd.Pos = prologueEnd.Pos.WithXlogue(src.PosPrologueEnd) + + if objabi.Framepointer_enabled { + 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 + + 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), R1 + // CBNZ checkargp + // end: + // NOP + // ... function body ... + // checkargp: + // MOV panic_argp(R1), R2 + // ADD $(autosize+8), RSP, R3 + // CMP R2, R3 + // BNE end + // ADD $8, RSP, R4 + // MOVD R4, panic_argp(R1) + // 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), R1 + 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_R1 + + // CBNZ R1, checkargp + cbnz := obj.Appendp(q, c.newprog) + cbnz.As = ACBNZ + cbnz.From.Type = obj.TYPE_REG + cbnz.From.Reg = REG_R1 + 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(R1), R2 + mov := obj.Appendp(last, c.newprog) + mov.As = AMOVD + mov.From.Type = obj.TYPE_MEM + mov.From.Reg = REG_R1 + mov.From.Offset = 0 // Panic.argp + mov.To.Type = obj.TYPE_REG + mov.To.Reg = REG_R2 + + // CBNZ branches to the MOV above + cbnz.To.SetTarget(mov) + + // ADD $(autosize+8), SP, R3 + 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_R3 + + // CMP R2, R3 + q = obj.Appendp(q, c.newprog) + q.As = ACMP + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R2 + q.Reg = REG_R3 + + // BNE end + q = obj.Appendp(q, c.newprog) + q.As = ABNE + q.To.Type = obj.TYPE_BRANCH + q.To.SetTarget(end) + + // ADD $8, SP, R4 + 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_R4 + + // MOV R4, panic_argp(R1) + q = obj.Appendp(q, c.newprog) + q.As = AMOVD + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R4 + q.To.Type = obj.TYPE_MEM + q.To.Reg = REG_R1 + 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 + + if objabi.Framepointer_enabled { + 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 { + /* want write-back pre-indexed SP+autosize -> SP, loading REGLINK*/ + + if objabi.Framepointer_enabled { + 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 + p = obj.Appendp(p, c.newprog) + } + + aoffset := c.autosize + + if aoffset <= 0xF0 { + p.As = AMOVD + p.From.Type = obj.TYPE_MEM + p.Scond = C_XPOST + p.From.Offset = int64(aoffset) + p.From.Reg = REGSP + p.To.Type = obj.TYPE_REG + p.To.Reg = REGLINK + p.Spadj = -aoffset + } else { + p.As = AMOVD + p.From.Type = obj.TYPE_MEM + p.From.Offset = 0 + p.From.Reg = REGSP + p.To.Type = obj.TYPE_REG + p.To.Reg = REGLINK + + 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.Link = p.Link + q.Spadj = int32(-q.From.Offset) + q.Pos = p.Pos + p.Link = q + p = q + } + } + + 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: + if objabi.Framepointer_enabled { + // 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 + + // maintaine 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: + if objabi.Framepointer_enabled { + // 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 + + // maintaine 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 + } + } + } +} + +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, +} |