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[dev.ssa] cmd/compile: use function calls instead of special ops for panics

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There's no need for special ops for panicindex and panicslice.
Just use regular runtime calls.

Change-Id: I71b9b73f4f1ebce1220fdc1e7b7f65cfcf4b7bae
Reviewed-on: https://go-review.googlesource.com/14726
Reviewed-by: David Chase <drchase@google.com>
This commit is contained in:
Keith Randall 2015-09-17 16:54:15 -07:00
parent 8c5bfcc52b
commit 3a70bf9c0c
6 changed files with 9 additions and 79 deletions
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26
src/cmd/compile/internal/gc/ssa.go
View File

@ -2312,7 +2312,7 @@ func (s *state) boundsCheck(idx, len *ssa.Value) {
// bounds check
cmp := s.newValue2(ssa.OpIsInBounds, Types[TBOOL], idx, len)
s.check(cmp, ssa.OpPanicIndexCheck)
s.check(cmp, Panicindex)
}
// sliceBoundsCheck generates slice bounds checking code. Checks if 0 <= idx <= len, branches to exit if not.
@ -2326,11 +2326,11 @@ func (s *state) sliceBoundsCheck(idx, len *ssa.Value) {
// bounds check
cmp := s.newValue2(ssa.OpIsSliceInBounds, Types[TBOOL], idx, len)
s.check(cmp, ssa.OpPanicSliceCheck)
s.check(cmp, panicslice)
}
// If cmp (a bool) is true, panic using the given op.
func (s *state) check(cmp *ssa.Value, panicOp ssa.Op) {
// If cmp (a bool) is true, panic using the given function.
func (s *state) check(cmp *ssa.Value, fn *Node) {
b := s.endBlock()
b.Kind = ssa.BlockIf
b.Control = cmp
@ -2340,12 +2340,10 @@ func (s *state) check(cmp *ssa.Value, panicOp ssa.Op) {
b.AddEdgeTo(bNext)
b.AddEdgeTo(bPanic)
s.startBlock(bPanic)
// The panic check takes/returns memory to ensure that the right
// The panic call takes/returns memory to ensure that the right
// memory state is observed if the panic happens.
chk := s.newValue1(panicOp, ssa.TypeMem, s.mem())
s.endBlock()
bPanic.Kind = ssa.BlockExit
bPanic.Control = chk
s.rtcall(fn, false, nil)
s.startBlock(bNext)
}
@ -3700,16 +3698,6 @@ func (s *genState) genValue(v *ssa.Value) {
q.From.Reg = x86.REG_AX
q.To.Type = obj.TYPE_MEM
q.To.Reg = r
case ssa.OpAMD64LoweredPanicIndexCheck:
p := Prog(obj.ACALL)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = Linksym(Panicindex.Sym)
case ssa.OpAMD64LoweredPanicSliceCheck:
p := Prog(obj.ACALL)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = Linksym(panicslice.Sym)
case ssa.OpAMD64LoweredGetG:
r := regnum(v)
// See the comments in cmd/internal/obj/x86/obj6.go

2
src/cmd/compile/internal/ssa/gen/AMD64.rules
View File

@ -287,8 +287,6 @@
(IsSliceInBounds idx len) -> (SETBE (CMPQ idx len))
(PanicNilCheck ptr mem) -> (LoweredPanicNilCheck ptr mem)
(PanicIndexCheck mem) -> (LoweredPanicIndexCheck mem)
(PanicSliceCheck mem) -> (LoweredPanicSliceCheck mem)
(GetG) -> (LoweredGetG)
(Move [size] dst src mem) -> (REPMOVSB dst src (MOVQconst <config.Frontend().TypeUInt64()> [size]) mem)

2
src/cmd/compile/internal/ssa/gen/AMD64Ops.go
View File

@ -403,8 +403,6 @@ func init() {
// Pseudo-ops
{name: "LoweredPanicNilCheck", reg: gp10},
{name: "LoweredPanicIndexCheck"},
{name: "LoweredPanicSliceCheck"},
{name: "LoweredGetG", reg: gp01},
}

6
src/cmd/compile/internal/ssa/gen/genericOps.go
View File

@ -325,10 +325,8 @@ var genericOps = []opData{
{name: "IsSliceInBounds", typ: "Bool"}, // 0 <= arg0 <= arg1
// Pseudo-ops
{name: "PanicNilCheck"}, // trigger a dereference fault; arg0=nil ptr, arg1=mem, returns mem
{name: "PanicIndexCheck"}, // trigger a bounds check failure, arg0=mem, returns mem
{name: "PanicSliceCheck"}, // trigger a slice bounds check failure, arg0=mem, returns mem
{name: "GetG"}, // runtime.getg() (read g pointer)
{name: "PanicNilCheck"}, // trigger a dereference fault; arg0=nil ptr, arg1=mem, returns mem
{name: "GetG"}, // runtime.getg() (read g pointer)
// Indexing operations
{name: "ArrayIndex"}, // arg0=array, arg1=index. Returns a[i]

20
src/cmd/compile/internal/ssa/opGen.go
View File

@ -270,8 +270,6 @@ const (
OpAMD64REPMOVSB
OpAMD64InvertFlags
OpAMD64LoweredPanicNilCheck
OpAMD64LoweredPanicIndexCheck
OpAMD64LoweredPanicSliceCheck
OpAMD64LoweredGetG
OpAdd8
@ -513,8 +511,6 @@ const (
OpIsInBounds
OpIsSliceInBounds
OpPanicNilCheck
OpPanicIndexCheck
OpPanicSliceCheck
OpGetG
OpArrayIndex
OpPtrIndex
@ -3115,14 +3111,6 @@ var opcodeTable = [...]opInfo{
},
},
},
{
name: "LoweredPanicIndexCheck",
reg: regInfo{},
},
{
name: "LoweredPanicSliceCheck",
reg: regInfo{},
},
{
name: "LoweredGetG",
reg: regInfo{
@ -4088,14 +4076,6 @@ var opcodeTable = [...]opInfo{
name: "PanicNilCheck",
generic: true,
},
{
name: "PanicIndexCheck",
generic: true,
},
{
name: "PanicSliceCheck",
generic: true,
},
{
name: "GetG",
generic: true,

32
src/cmd/compile/internal/ssa/rewriteAMD64.go
View File

@ -6905,22 +6905,6 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
goto end6f8a8c559a167d1f0a5901d09a1fb248
end6f8a8c559a167d1f0a5901d09a1fb248:
;
case OpPanicIndexCheck:
// match: (PanicIndexCheck mem)
// cond:
// result: (LoweredPanicIndexCheck mem)
{
mem := v.Args[0]
v.Op = OpAMD64LoweredPanicIndexCheck
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AddArg(mem)
return true
}
goto enda5014ba73d3550a5b66424044395c70f
enda5014ba73d3550a5b66424044395c70f:
;
case OpPanicNilCheck:
// match: (PanicNilCheck ptr mem)
// cond:
@ -6939,22 +6923,6 @@ func rewriteValueAMD64(v *Value, config *Config) bool {
goto enda02b1ad5a6f929b782190145f2c8628b
enda02b1ad5a6f929b782190145f2c8628b:
;
case OpPanicSliceCheck:
// match: (PanicSliceCheck mem)
// cond:
// result: (LoweredPanicSliceCheck mem)
{
mem := v.Args[0]
v.Op = OpAMD64LoweredPanicSliceCheck
v.AuxInt = 0
v.Aux = nil
v.resetArgs()
v.AddArg(mem)
return true
}
goto end238ed0074810b55bd2bba7b45cdeed68
end238ed0074810b55bd2bba7b45cdeed68:
;
case OpRsh16Ux16:
// match: (Rsh16Ux16 <t> x y)
// cond: