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[dev.typeparams] cmd/internal/obj/arm64: use ABI-compatible registers in function prologue

Avoid using R1, R2, etc. in function prologue, which may carry
live argument values.

Change-Id: I80322b3f7e8fda7aaff622aaa99bc76d02e09727
Reviewed-on: https://go-review.googlesource.com/c/go/+/322852
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: David Chase <drchase@google.com>
This commit is contained in:
Cherry Mui 2021-05-25 18:08:36 -04:00
parent 4bb927f82e
commit a4b2a04bc5

View File

@ -52,7 +52,7 @@ var complements = []obj.As{
}
func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
// MOV g_stackguard(g), R1
// MOV g_stackguard(g), RT1
p = obj.Appendp(p, c.newprog)
p.As = AMOVD
@ -63,7 +63,7 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
p.From.Offset = 3 * int64(c.ctxt.Arch.PtrSize) // G.stackguard1
}
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R1
p.To.Reg = REGRT1
// Mark the stack bound check and morestack call async nonpreemptible.
// If we get preempted here, when resumed the preemption request is
@ -74,25 +74,25 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
q := (*obj.Prog)(nil)
if framesize <= objabi.StackSmall {
// small stack: SP < stackguard
// MOV SP, R2
// CMP stackguard, R2
// MOV SP, RT2
// CMP stackguard, RT2
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.To.Reg = REGRT2
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
p.From.Reg = REGRT1
p.Reg = REGRT2
} else if framesize <= objabi.StackBig {
// large stack: SP-framesize < stackguard-StackSmall
// SUB $(framesize-StackSmall), SP, R2
// CMP stackguard, R2
// SUB $(framesize-StackSmall), SP, RT2
// CMP stackguard, RT2
p = obj.Appendp(p, c.newprog)
p.As = ASUB
@ -100,13 +100,13 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
p.From.Offset = int64(framesize) - objabi.StackSmall
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p.To.Reg = REGRT2
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
p.From.Reg = REGRT1
p.Reg = REGRT2
} else {
// Such a large stack we need to protect against underflow.
// The runtime guarantees SP > objabi.StackBig, but
@ -115,10 +115,10 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
// stack guard to incorrectly succeed. We explicitly
// guard against underflow.
//
// SUBS $(framesize-StackSmall), SP, R2
// SUBS $(framesize-StackSmall), SP, RT2
// // On underflow, jump to morestack
// BLO label_of_call_to_morestack
// CMP stackguard, R2
// CMP stackguard, RT2
p = obj.Appendp(p, c.newprog)
p.As = ASUBS
@ -126,7 +126,7 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
p.From.Offset = int64(framesize) - objabi.StackSmall
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p.To.Reg = REGRT2
p = obj.Appendp(p, c.newprog)
q = p
@ -136,8 +136,8 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
p = obj.Appendp(p, c.newprog)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
p.From.Reg = REGRT1
p.Reg = REGRT2
}
// BLS do-morestack
@ -631,38 +631,38 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
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
// MOV g_panic(g), RT1
// CBNZ checkargp
// end:
// NOP
// ... function body ...
// checkargp:
// MOV panic_argp(R1), R2
// ADD $(autosize+8), RSP, R3
// CMP R2, R3
// MOV panic_argp(RT1), RT2
// ADD $(autosize+8), RSP, R20
// CMP RT2, R20
// BNE end
// ADD $8, RSP, R4
// MOVD R4, panic_argp(R1)
// ADD $8, RSP, R20
// MOVD R20, panic_argp(RT1)
// 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
// MOV g_panic(g), RT1
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
q.To.Reg = REGRT1
// CBNZ R1, checkargp
// CBNZ RT1, checkargp
cbnz := obj.Appendp(q, c.newprog)
cbnz.As = ACBNZ
cbnz.From.Type = obj.TYPE_REG
cbnz.From.Reg = REG_R1
cbnz.From.Reg = REGRT1
cbnz.To.Type = obj.TYPE_BRANCH
// Empty branch target at the top of the function body
@ -674,33 +674,33 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
for last = end; last.Link != nil; last = last.Link {
}
// MOV panic_argp(R1), R2
// MOV panic_argp(RT1), RT2
mov := obj.Appendp(last, c.newprog)
mov.As = AMOVD
mov.From.Type = obj.TYPE_MEM
mov.From.Reg = REG_R1
mov.From.Reg = REGRT1
mov.From.Offset = 0 // Panic.argp
mov.To.Type = obj.TYPE_REG
mov.To.Reg = REG_R2
mov.To.Reg = REGRT2
// CBNZ branches to the MOV above
cbnz.To.SetTarget(mov)
// ADD $(autosize+8), SP, R3
// ADD $(autosize+8), SP, R20
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
q.To.Reg = REG_R20
// CMP R2, R3
// CMP RT2, R20
q = obj.Appendp(q, c.newprog)
q.As = ACMP
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R2
q.Reg = REG_R3
q.From.Reg = REGRT2
q.Reg = REG_R20
// BNE end
q = obj.Appendp(q, c.newprog)
@ -708,22 +708,22 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
q.To.Type = obj.TYPE_BRANCH
q.To.SetTarget(end)
// ADD $8, SP, R4
// ADD $8, SP, R20
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
q.To.Reg = REG_R20
// MOV R4, panic_argp(R1)
// MOV R20, panic_argp(RT1)
q = obj.Appendp(q, c.newprog)
q.As = AMOVD
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_R4
q.From.Reg = REG_R20
q.To.Type = obj.TYPE_MEM
q.To.Reg = REG_R1
q.To.Reg = REGRT1
q.To.Offset = 0 // Panic.argp
// B end