diff options
Diffstat (limited to 'src/cmd/internal/obj/mips/obj0.go')
-rw-r--r-- | src/cmd/internal/obj/mips/obj0.go | 1522 |
1 files changed, 1522 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/mips/obj0.go b/src/cmd/internal/obj/mips/obj0.go new file mode 100644 index 0000000..b96a28a --- /dev/null +++ b/src/cmd/internal/obj/mips/obj0.go @@ -0,0 +1,1522 @@ +// cmd/9l/noop.c, cmd/9l/pass.c, cmd/9l/span.c from Vita Nuova. +// +// 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 mips + +import ( + "cmd/internal/obj" + "cmd/internal/objabi" + "cmd/internal/sys" + "encoding/binary" + "fmt" + "log" + "math" +) + +func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) { + c := ctxt0{ctxt: ctxt, newprog: newprog} + + p.From.Class = 0 + p.To.Class = 0 + + // 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 && c.ctxt.Arch.Family == sys.MIPS64 { + 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 + } + + // Put >32-bit constants in memory and load them + case AMOVV: + if p.From.Type == obj.TYPE_CONST && p.From.Name == obj.NAME_NONE && p.From.Reg == 0 && int64(int32(p.From.Offset)) != p.From.Offset { + 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 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 + } + } +} + +func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { + // TODO(minux): add morestack short-cuts with small fixed frame-size. + c := ctxt0{ctxt: ctxt, newprog: newprog, cursym: cursym} + + // a switch for enabling/disabling instruction scheduling + nosched := true + + if c.cursym.Func().Text == nil || c.cursym.Func().Text.Link == nil { + return + } + + p := c.cursym.Func().Text + textstksiz := p.To.Offset + if textstksiz == -ctxt.FixedFrameSize() { + // 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 + * expand RET + * expand BECOME pseudo + */ + + for p := c.cursym.Func().Text; p != nil; p = p.Link { + switch p.As { + /* too hard, just leave alone */ + case obj.ATEXT: + p.Mark |= LABEL | LEAF | SYNC + if p.Link != nil { + p.Link.Mark |= LABEL + } + + /* too hard, just leave alone */ + 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 + } + + /* too hard, just leave alone */ + case ASYSCALL, + AWORD, + ATLBWR, + ATLBWI, + ATLBP, + ATLBR: + p.Mark |= LABEL | SYNC + + case ANOR: + if p.To.Type == obj.TYPE_REG { + if p.To.Reg == REGZERO { + p.Mark |= LABEL | SYNC + } + } + + case ABGEZAL, + ABLTZAL, + AJAL, + obj.ADUFFZERO, + obj.ADUFFCOPY: + c.cursym.Func().Text.Mark &^= LEAF + fallthrough + + case AJMP, + ABEQ, + ABGEZ, + ABGTZ, + ABLEZ, + ABLTZ, + ABNE, + ABFPT, ABFPF: + if p.As == ABFPT || p.As == ABFPF { + // We don't treat ABFPT and ABFPF as branches here, + // so that we will always fill nop (0x0) in their + // delay slot during assembly. + // This is to workaround a kernel FPU emulator bug + // where it uses the user stack to simulate the + // instruction in the delay slot if it's not 0x0, + // and somehow that leads to SIGSEGV when the kernel + // jump to the stack. + p.Mark |= SYNC + } else { + 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 + } + } + //else { + // p.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 + if c.ctxt.Arch.Family == sys.MIPS64 { + add = AADDV + mov = AMOVV + } else { + add = AADDU + mov = AMOVW + } + + 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.FixedFrameSize()) + } + + if autosize&4 != 0 && c.ctxt.Arch.Family == sys.MIPS64 { + 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.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) + } + + 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), R1 + // BEQ R1, end + // MOV panic_argp(R1), R2 + // ADD $(autosize+FIXED_FRAME), R29, R3 + // BNE R2, R3, end + // ADD $FIXED_FRAME, R29, R2 + // MOV R2, panic_argp(R1) + // end: + // NOP + // + // The NOP is needed to give the jumps somewhere to land. + // It is a liblink NOP, not an mips 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_R1 + + q = obj.Appendp(q, newprog) + q.As = ABEQ + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R1 + 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_R1 + q.From.Offset = 0 // Panic.argp + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R2 + + q = obj.Appendp(q, newprog) + q.As = add + q.From.Type = obj.TYPE_CONST + q.From.Offset = int64(autosize) + ctxt.FixedFrameSize() + q.Reg = REGSP + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R3 + + q = obj.Appendp(q, newprog) + q.As = ABNE + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R2 + q.Reg = REG_R3 + 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.FixedFrameSize() + q.Reg = REGSP + q.To.Type = obj.TYPE_REG + q.To.Reg = REG_R2 + + q = obj.Appendp(q, newprog) + q.As = mov + q.From.Type = obj.TYPE_REG + q.From.Reg = REG_R2 + q.To.Type = obj.TYPE_MEM + q.To.Reg = REG_R1 + 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.Reg = REGLINK + q.To.Offset = 0 + } + 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&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 c.ctxt.Arch.Family == sys.MIPS { + // rewrite MOVD into two MOVF in 32-bit mode to avoid unaligned memory access + for p = c.cursym.Func().Text; p != nil; p = p1 { + p1 = p.Link + + if p.As != AMOVD { + continue + } + if p.From.Type != obj.TYPE_MEM && p.To.Type != obj.TYPE_MEM { + continue + } + + p.As = AMOVF + q = c.newprog() + *q = *p + q.Link = p.Link + p.Link = q + p1 = q.Link + + var addrOff int64 + if c.ctxt.Arch.ByteOrder == binary.BigEndian { + addrOff = 4 // swap load/save order + } + if p.From.Type == obj.TYPE_MEM { + reg := REG_F0 + (p.To.Reg-REG_F0)&^1 + p.To.Reg = reg + q.To.Reg = reg + 1 + p.From.Offset += addrOff + q.From.Offset += 4 - addrOff + } else if p.To.Type == obj.TYPE_MEM { + reg := REG_F0 + (p.From.Reg-REG_F0)&^1 + p.From.Reg = reg + q.From.Reg = reg + 1 + p.To.Offset += addrOff + q.To.Offset += 4 - addrOff + } + } + } + + if nosched { + // if we don't do instruction scheduling, simply add + // NOP after each branch instruction. + for p = c.cursym.Func().Text; p != nil; p = p.Link { + if p.Mark&BRANCH != 0 { + c.addnop(p) + } + } + return + } + + // instruction scheduling + q = nil // p - 1 + q1 = c.cursym.Func().Text // top of block + o := 0 // count of instructions + for p = c.cursym.Func().Text; p != nil; p = p1 { + p1 = p.Link + o++ + if p.Mark&NOSCHED != 0 { + if q1 != p { + c.sched(q1, q) + } + for ; p != nil; p = p.Link { + if p.Mark&NOSCHED == 0 { + break + } + q = p + } + p1 = p + q1 = p + o = 0 + continue + } + if p.Mark&(LABEL|SYNC) != 0 { + if q1 != p { + c.sched(q1, q) + } + q1 = p + o = 1 + } + if p.Mark&(BRANCH|SYNC) != 0 { + c.sched(q1, p) + q1 = p1 + o = 0 + } + if o >= NSCHED { + c.sched(q1, p) + q1 = p1 + o = 0 + } + q = p + } +} + +func (c *ctxt0) stacksplit(p *obj.Prog, framesize int32) *obj.Prog { + var mov, add obj.As + + if c.ctxt.Arch.Family == sys.MIPS64 { + add = AADDV + mov = AMOVV + } else { + add = AADDU + mov = AMOVW + } + + if c.ctxt.Flag_maymorestack != "" { + // Save LR and REGCTXT. + frameSize := 2 * c.ctxt.Arch.PtrSize + + p = c.ctxt.StartUnsafePoint(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) + + p = c.ctxt.EndUnsafePoint(p, c.newprog, -1) + } + + // Jump back to here after morestack returns. + startPred := p + + // MOV g_stackguard(g), R1 + 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_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) + + var q *obj.Prog + if framesize <= objabi.StackSmall { + // small stack: SP < stackguard + // AGTU SP, stackguard, R1 + p = obj.Appendp(p, c.newprog) + + p.As = ASGTU + p.From.Type = obj.TYPE_REG + p.From.Reg = REGSP + p.Reg = REG_R1 + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R1 + } else { + // 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. + // + // SGTU $(framesize-StackSmall), SP, R2 + // BNE R2, 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_R2 + + p = obj.Appendp(p, c.newprog) + q = p + p.As = ABNE + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R2 + p.To.Type = obj.TYPE_BRANCH + p.Mark |= BRANCH + } + + // Check against the stack guard. We've ensured this won't underflow. + // ADD $-(framesize-StackSmall), SP, R2 + // SGTU R2, stackguard, R1 + 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_R2 + + p = obj.Appendp(p, c.newprog) + p.As = ASGTU + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R2 + p.Reg = REG_R1 + p.To.Type = obj.TYPE_REG + p.To.Reg = REG_R1 + } + + // q1: BNE R1, done + p = obj.Appendp(p, c.newprog) + q1 := p + + p.As = ABNE + p.From.Type = obj.TYPE_REG + p.From.Reg = REG_R1 + p.To.Type = obj.TYPE_BRANCH + p.Mark |= BRANCH + + // MOV LINK, R3 + 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_R3 + if q != nil { + q.To.SetTarget(p) + p.Mark |= LABEL + } + + p = c.ctxt.EmitEntryStackMap(c.cursym, 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.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 +} + +const ( + E_HILO = 1 << 0 + E_FCR = 1 << 1 + E_MCR = 1 << 2 + E_MEM = 1 << 3 + E_MEMSP = 1 << 4 /* uses offset and size */ + E_MEMSB = 1 << 5 /* uses offset and size */ + ANYMEM = E_MEM | E_MEMSP | E_MEMSB + //DELAY = LOAD|BRANCH|FCMP + DELAY = BRANCH /* only schedule branch */ +) + +type Dep struct { + ireg uint32 + freg uint32 + cc uint32 +} + +type Sch struct { + p obj.Prog + set Dep + used Dep + soffset int32 + size uint8 + nop uint8 + comp bool +} + +func (c *ctxt0) sched(p0, pe *obj.Prog) { + var sch [NSCHED]Sch + + /* + * build side structure + */ + s := sch[:] + for p := p0; ; p = p.Link { + s[0].p = *p + c.markregused(&s[0]) + if p == pe { + break + } + s = s[1:] + } + se := s + + for i := cap(sch) - cap(se); i >= 0; i-- { + s = sch[i:] + if s[0].p.Mark&DELAY == 0 { + continue + } + if -cap(s) < -cap(se) { + if !conflict(&s[0], &s[1]) { + continue + } + } + + var t []Sch + var j int + for j = cap(sch) - cap(s) - 1; j >= 0; j-- { + t = sch[j:] + if t[0].comp { + if s[0].p.Mark&BRANCH != 0 { + continue + } + } + if t[0].p.Mark&DELAY != 0 { + if -cap(s) >= -cap(se) || conflict(&t[0], &s[1]) { + continue + } + } + for u := t[1:]; -cap(u) <= -cap(s); u = u[1:] { + if c.depend(&u[0], &t[0]) { + continue + } + } + goto out2 + } + + if s[0].p.Mark&BRANCH != 0 { + s[0].nop = 1 + } + continue + + out2: + // t[0] is the instruction being moved to fill the delay + stmp := t[0] + copy(t[:i-j], t[1:i-j+1]) + s[0] = stmp + + if t[i-j-1].p.Mark&BRANCH != 0 { + // t[i-j] is being put into a branch delay slot + // combine its Spadj with the branch instruction + t[i-j-1].p.Spadj += t[i-j].p.Spadj + t[i-j].p.Spadj = 0 + } + + i-- + } + + /* + * put it all back + */ + var p *obj.Prog + var q *obj.Prog + for s, p = sch[:], p0; -cap(s) <= -cap(se); s, p = s[1:], q { + q = p.Link + if q != s[0].p.Link { + *p = s[0].p + p.Link = q + } + for s[0].nop != 0 { + s[0].nop-- + c.addnop(p) + } + } +} + +func (c *ctxt0) markregused(s *Sch) { + p := &s.p + s.comp = c.compound(p) + s.nop = 0 + if s.comp { + s.set.ireg |= 1 << (REGTMP - REG_R0) + s.used.ireg |= 1 << (REGTMP - REG_R0) + } + + ar := 0 /* dest is really reference */ + ad := 0 /* source/dest is really address */ + ld := 0 /* opcode is load instruction */ + sz := 20 /* size of load/store for overlap computation */ + + /* + * flags based on opcode + */ + switch p.As { + case obj.ATEXT: + c.autosize = int32(p.To.Offset + 8) + ad = 1 + + case AJAL: + r := p.Reg + if r == 0 { + r = REGLINK + } + s.set.ireg |= 1 << uint(r-REG_R0) + ar = 1 + ad = 1 + + case ABGEZAL, + ABLTZAL: + s.set.ireg |= 1 << (REGLINK - REG_R0) + fallthrough + case ABEQ, + ABGEZ, + ABGTZ, + ABLEZ, + ABLTZ, + ABNE: + ar = 1 + ad = 1 + + case ABFPT, + ABFPF: + ad = 1 + s.used.cc |= E_FCR + + case ACMPEQD, + ACMPEQF, + ACMPGED, + ACMPGEF, + ACMPGTD, + ACMPGTF: + ar = 1 + s.set.cc |= E_FCR + p.Mark |= FCMP + + case AJMP: + ar = 1 + ad = 1 + + case AMOVB, + AMOVBU: + sz = 1 + ld = 1 + + case AMOVH, + AMOVHU: + sz = 2 + ld = 1 + + case AMOVF, + AMOVW, + AMOVWL, + AMOVWR: + sz = 4 + ld = 1 + + case AMOVD, + AMOVV, + AMOVVL, + AMOVVR: + sz = 8 + ld = 1 + + case ADIV, + ADIVU, + AMUL, + AMULU, + AREM, + AREMU, + ADIVV, + ADIVVU, + AMULV, + AMULVU, + AREMV, + AREMVU: + s.set.cc = E_HILO + fallthrough + case AADD, + AADDU, + AADDV, + AADDVU, + AAND, + ANOR, + AOR, + ASGT, + ASGTU, + ASLL, + ASRA, + ASRL, + ASLLV, + ASRAV, + ASRLV, + ASUB, + ASUBU, + ASUBV, + ASUBVU, + AXOR, + + AADDD, + AADDF, + AADDW, + ASUBD, + ASUBF, + ASUBW, + AMULF, + AMULD, + AMULW, + ADIVF, + ADIVD, + ADIVW: + if p.Reg == 0 { + if p.To.Type == obj.TYPE_REG { + p.Reg = p.To.Reg + } + //if(p->reg == NREG) + // print("botch %P\n", p); + } + } + + /* + * flags based on 'to' field + */ + cls := int(p.To.Class) + if cls == 0 { + cls = c.aclass(&p.To) + 1 + p.To.Class = int8(cls) + } + cls-- + switch cls { + default: + fmt.Printf("unknown class %d %v\n", cls, p) + + case C_ZCON, + C_SCON, + C_ADD0CON, + C_AND0CON, + C_ADDCON, + C_ANDCON, + C_UCON, + C_LCON, + C_NONE, + C_SBRA, + C_LBRA, + C_ADDR, + C_TEXTSIZE: + break + + case C_HI, + C_LO: + s.set.cc |= E_HILO + + case C_FCREG: + s.set.cc |= E_FCR + + case C_MREG: + s.set.cc |= E_MCR + + case C_ZOREG, + C_SOREG, + C_LOREG: + cls = int(p.To.Reg) + s.used.ireg |= 1 << uint(cls-REG_R0) + if ad != 0 { + break + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.To) + + m := uint32(ANYMEM) + if cls == REGSB { + m = E_MEMSB + } + if cls == REGSP { + m = E_MEMSP + } + + if ar != 0 { + s.used.cc |= m + } else { + s.set.cc |= m + } + + case C_SACON, + C_LACON: + s.used.ireg |= 1 << (REGSP - REG_R0) + + case C_SECON, + C_LECON: + s.used.ireg |= 1 << (REGSB - REG_R0) + + case C_REG: + if ar != 0 { + s.used.ireg |= 1 << uint(p.To.Reg-REG_R0) + } else { + s.set.ireg |= 1 << uint(p.To.Reg-REG_R0) + } + + case C_FREG: + if ar != 0 { + s.used.freg |= 1 << uint(p.To.Reg-REG_F0) + } else { + s.set.freg |= 1 << uint(p.To.Reg-REG_F0) + } + if ld != 0 && p.From.Type == obj.TYPE_REG { + p.Mark |= LOAD + } + + case C_SAUTO, + C_LAUTO: + s.used.ireg |= 1 << (REGSP - REG_R0) + if ad != 0 { + break + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.To) + + if ar != 0 { + s.used.cc |= E_MEMSP + } else { + s.set.cc |= E_MEMSP + } + + case C_SEXT, + C_LEXT: + s.used.ireg |= 1 << (REGSB - REG_R0) + if ad != 0 { + break + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.To) + + if ar != 0 { + s.used.cc |= E_MEMSB + } else { + s.set.cc |= E_MEMSB + } + } + + /* + * flags based on 'from' field + */ + cls = int(p.From.Class) + if cls == 0 { + cls = c.aclass(&p.From) + 1 + p.From.Class = int8(cls) + } + cls-- + switch cls { + default: + fmt.Printf("unknown class %d %v\n", cls, p) + + case C_ZCON, + C_SCON, + C_ADD0CON, + C_AND0CON, + C_ADDCON, + C_ANDCON, + C_UCON, + C_LCON, + C_NONE, + C_SBRA, + C_LBRA, + C_ADDR, + C_TEXTSIZE: + break + + case C_HI, + C_LO: + s.used.cc |= E_HILO + + case C_FCREG: + s.used.cc |= E_FCR + + case C_MREG: + s.used.cc |= E_MCR + + case C_ZOREG, + C_SOREG, + C_LOREG: + cls = int(p.From.Reg) + s.used.ireg |= 1 << uint(cls-REG_R0) + if ld != 0 { + p.Mark |= LOAD + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.From) + + m := uint32(ANYMEM) + if cls == REGSB { + m = E_MEMSB + } + if cls == REGSP { + m = E_MEMSP + } + + s.used.cc |= m + + case C_SACON, + C_LACON: + cls = int(p.From.Reg) + if cls == 0 { + cls = REGSP + } + s.used.ireg |= 1 << uint(cls-REG_R0) + + case C_SECON, + C_LECON: + s.used.ireg |= 1 << (REGSB - REG_R0) + + case C_REG: + s.used.ireg |= 1 << uint(p.From.Reg-REG_R0) + + case C_FREG: + s.used.freg |= 1 << uint(p.From.Reg-REG_F0) + if ld != 0 && p.To.Type == obj.TYPE_REG { + p.Mark |= LOAD + } + + case C_SAUTO, + C_LAUTO: + s.used.ireg |= 1 << (REGSP - REG_R0) + if ld != 0 { + p.Mark |= LOAD + } + if ad != 0 { + break + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.From) + + s.used.cc |= E_MEMSP + + case C_SEXT: + case C_LEXT: + s.used.ireg |= 1 << (REGSB - REG_R0) + if ld != 0 { + p.Mark |= LOAD + } + if ad != 0 { + break + } + s.size = uint8(sz) + s.soffset = c.regoff(&p.From) + + s.used.cc |= E_MEMSB + } + + cls = int(p.Reg) + if cls != 0 { + if REG_F0 <= cls && cls <= REG_F31 { + s.used.freg |= 1 << uint(cls-REG_F0) + } else { + s.used.ireg |= 1 << uint(cls-REG_R0) + } + } + s.set.ireg &^= (1 << (REGZERO - REG_R0)) /* R0 can't be set */ +} + +/* + * test to see if two instructions can be + * interchanged without changing semantics + */ +func (c *ctxt0) depend(sa, sb *Sch) bool { + if sa.set.ireg&(sb.set.ireg|sb.used.ireg) != 0 { + return true + } + if sb.set.ireg&sa.used.ireg != 0 { + return true + } + + if sa.set.freg&(sb.set.freg|sb.used.freg) != 0 { + return true + } + if sb.set.freg&sa.used.freg != 0 { + return true + } + + /* + * special case. + * loads from same address cannot pass. + * this is for hardware fifo's and the like + */ + if sa.used.cc&sb.used.cc&E_MEM != 0 { + if sa.p.Reg == sb.p.Reg { + if c.regoff(&sa.p.From) == c.regoff(&sb.p.From) { + return true + } + } + } + + x := (sa.set.cc & (sb.set.cc | sb.used.cc)) | (sb.set.cc & sa.used.cc) + if x != 0 { + /* + * allow SB and SP to pass each other. + * allow SB to pass SB iff doffsets are ok + * anything else conflicts + */ + if x != E_MEMSP && x != E_MEMSB { + return true + } + x = sa.set.cc | sb.set.cc | sa.used.cc | sb.used.cc + if x&E_MEM != 0 { + return true + } + if offoverlap(sa, sb) { + return true + } + } + + return false +} + +func offoverlap(sa, sb *Sch) bool { + if sa.soffset < sb.soffset { + if sa.soffset+int32(sa.size) > sb.soffset { + return true + } + return false + } + if sb.soffset+int32(sb.size) > sa.soffset { + return true + } + return false +} + +/* + * test 2 adjacent instructions + * and find out if inserted instructions + * are desired to prevent stalls. + */ +func conflict(sa, sb *Sch) bool { + if sa.set.ireg&sb.used.ireg != 0 { + return true + } + if sa.set.freg&sb.used.freg != 0 { + return true + } + if sa.set.cc&sb.used.cc != 0 { + return true + } + return false +} + +func (c *ctxt0) compound(p *obj.Prog) bool { + o := c.oplook(p) + if o.size != 4 { + return true + } + if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSB { + return true + } + return false +} + +var Linkmips64 = obj.LinkArch{ + Arch: sys.ArchMIPS64, + Init: buildop, + Preprocess: preprocess, + Assemble: span0, + Progedit: progedit, + DWARFRegisters: MIPSDWARFRegisters, +} + +var Linkmips64le = obj.LinkArch{ + Arch: sys.ArchMIPS64LE, + Init: buildop, + Preprocess: preprocess, + Assemble: span0, + Progedit: progedit, + DWARFRegisters: MIPSDWARFRegisters, +} + +var Linkmips = obj.LinkArch{ + Arch: sys.ArchMIPS, + Init: buildop, + Preprocess: preprocess, + Assemble: span0, + Progedit: progedit, + DWARFRegisters: MIPSDWARFRegisters, +} + +var Linkmipsle = obj.LinkArch{ + Arch: sys.ArchMIPSLE, + Init: buildop, + Preprocess: preprocess, + Assemble: span0, + Progedit: progedit, + DWARFRegisters: MIPSDWARFRegisters, +} |