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Merge 1ea6cf68ec into 49cdf0c42e

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Wang Yaduo 2025-06-20 15:37:25 -04:00 committed by GitHub
parent 49cdf0c42e 1ea6cf68ec
commit b6a8e50167
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GPG Key ID: B5690EEEBB952194
1 changed files with 49 additions and 36 deletions
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85
src/cmd/internal/obj/riscv/obj.go
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@ -984,19 +984,20 @@ func stacksplit(ctxt *obj.Link, p *obj.Prog, cursym *obj.LSym, newprog obj.ProgA
// unnecessarily. See issue #35470.
p = ctxt.StartUnsafePoint(p, newprog)
var to_done, to_more *obj.Prog
var to_more *obj.Prog
to_more_big := (*obj.Prog)(nil)
if framesize <= abi.StackSmall {
// small stack
// // if SP > stackguard { goto done }
// BLTU stackguard, SP, done
// // if SP <= stackguard { goto label-of-call-to-morestack }
// BGEU stackguard, SP, label-of-call-to-morestack
p = obj.Appendp(p, newprog)
p.As = ABLTU
p.As = ABGEU
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_X6
p.Reg = REG_SP
p.To.Type = obj.TYPE_BRANCH
to_done = p
to_more = p
} else {
// large stack: SP-framesize < stackguard-StackSmall
offset := int64(framesize) - abi.StackSmall
@ -1024,13 +1025,13 @@ func stacksplit(ctxt *obj.Link, p *obj.Prog, cursym *obj.LSym, newprog obj.ProgA
p.From.Reg = REG_SP
p.Reg = REG_X7
p.To.Type = obj.TYPE_BRANCH
to_more = p
to_more_big = p
}
// Check against the stack guard. We've ensured this won't underflow.
// ADD $-(framesize-StackSmall), SP, X7
// // if X7 > stackguard { goto done }
// BLTU stackguard, X7, done
// // if X7 <= stackguard { goto label-of-call-to-morestack }
// BLTU stackguard, X7, label-of-call-to-morestack
p = obj.Appendp(p, newprog)
p.As = AADDI
p.From.Type = obj.TYPE_CONST
@ -1040,53 +1041,65 @@ func stacksplit(ctxt *obj.Link, p *obj.Prog, cursym *obj.LSym, newprog obj.ProgA
p.To.Reg = REG_X7
p = obj.Appendp(p, newprog)
p.As = ABLTU
p.As = ABGEU
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_X6
p.Reg = REG_X7
p.To.Type = obj.TYPE_BRANCH
to_done = p
to_more = p
}
end := ctxt.EndUnsafePoint(p, newprog, -1)
var last *obj.Prog
for last = 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, newprog)
spfix.As = obj.ANOP
spfix.Spadj = -int32(framesize)
pcdata := ctxt.EmitEntryStackMap(cursym, spfix, newprog)
pcdata = ctxt.StartUnsafePoint(pcdata, newprog)
if to_more_big != nil {
to_more_big.To.SetTarget(pcdata)
}
to_more.To.SetTarget(pcdata)
// Spill the register args that could be clobbered by the
// morestack code
p = ctxt.EmitEntryStackMap(cursym, p, newprog)
p = cursym.Func().SpillRegisterArgs(p, newprog)
spill := cursym.Func().SpillRegisterArgs(pcdata, newprog)
// CALL runtime.morestack(SB)
p = obj.Appendp(p, newprog)
p.As = obj.ACALL
p.To.Type = obj.TYPE_BRANCH
call := obj.Appendp(spill, newprog)
call.As = obj.ACALL
call.To.Type = obj.TYPE_BRANCH
if cursym.CFunc() {
p.To.Sym = ctxt.Lookup("runtime.morestackc")
call.To.Sym = ctxt.Lookup("runtime.morestackc")
} else if !cursym.Func().Text.From.Sym.NeedCtxt() {
p.To.Sym = ctxt.Lookup("runtime.morestack_noctxt")
call.To.Sym = ctxt.Lookup("runtime.morestack_noctxt")
} else {
p.To.Sym = ctxt.Lookup("runtime.morestack")
call.To.Sym = ctxt.Lookup("runtime.morestack")
}
if to_more != nil {
to_more.To.SetTarget(p)
}
jalToSym(ctxt, p, REG_X5)
jalToSym(ctxt, call, REG_X5)
// The instructions which unspill regs should be preemptible.
p = ctxt.EndUnsafePoint(p, newprog, -1)
p = cursym.Func().UnspillRegisterArgs(p, newprog)
pcdata = ctxt.EndUnsafePoint(call, newprog, -1)
unspill := cursym.Func().UnspillRegisterArgs(pcdata, newprog)
// JMP start
p = obj.Appendp(p, newprog)
p.As = AJAL
p.To = obj.Addr{Type: obj.TYPE_BRANCH}
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
p.To.SetTarget(startPred.Link)
jmp := obj.Appendp(unspill, newprog)
jmp.As = AJAL
jmp.To = obj.Addr{Type: obj.TYPE_BRANCH}
jmp.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
jmp.To.SetTarget(startPred.Link)
jmp.Spadj = +int32(framesize)
// placeholder for to_done's jump target
p = obj.Appendp(p, newprog)
p.As = obj.ANOP // zero-width place holder
to_done.To.SetTarget(p)
return p
return end
}
// signExtend sign extends val starting at bit bit.