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| author | Cherry Zhang <cherryyz@google.com> | 2016-07-13 09:22:48 -0600 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2016-07-15 18:20:29 +0000 |
| commit | 6adb97bde72b97310f9a75a4e286cd2ef236b271 (patch) | |
| tree | 5c560ce11f10e97ced0a9a138b65385426a1bf16 /src | |
| parent | 7bd88a651d0d9f8b314989475b337a0edf225bd1 (diff) | |
| download | go-6adb97bde72b97310f9a75a4e286cd2ef236b271.tar.xz | |
[dev.ssa] cmd/compile: fix argument size of runtime call in SSA for ARM
The argument size for runtime call was incorrectly includes the size
of LR (FixedFrameSize in general). This makes the stack frame
sometimes unnecessarily 4 bytes larger on ARM.
For example,
func f(b []byte) byte { return b[0] }
compiles to
0x0000 00000 (h.go:6) TEXT "".f(SB), $4-16 // <-- framesize = 4
0x0000 00000 (h.go:6) MOVW 8(g), R1
0x0004 00004 (h.go:6) CMP R1, R13
0x0008 00008 (h.go:6) BLS 52
0x000c 00012 (h.go:6) MOVW.W R14, -8(R13)
0x0010 00016 (h.go:6) FUNCDATA $0, gclocals·8355ad952265fec823c17fcf739bd009(SB)
0x0010 00016 (h.go:6) FUNCDATA $1, gclocals·69c1753bd5f81501d95132d08af04464(SB)
0x0010 00016 (h.go:6) MOVW "".b+4(FP), R0
0x0014 00020 (h.go:6) CMP $0, R0
0x0018 00024 (h.go:6) BLS 44
0x001c 00028 (h.go:6) MOVW "".b(FP), R0
0x0020 00032 (h.go:6) MOVBU (R0), R0
0x0024 00036 (h.go:6) MOVB R0, "".~r1+12(FP)
0x0028 00040 (h.go:6) MOVW.P 8(R13), R15
0x002c 00044 (h.go:6) PCDATA $0, $1
0x002c 00044 (h.go:6) CALL runtime.panicindex(SB)
0x0030 00048 (h.go:6) UNDEF
0x0034 00052 (h.go:6) NOP
0x0034 00052 (h.go:6) MOVW R14, R3
0x0038 00056 (h.go:6) CALL runtime.morestack_noctxt(SB)
0x003c 00060 (h.go:6) JMP 0
Note that the frame size is 4, but there is actually no local. It
incorrectly thinks call to runtime.panicindex needs 4 bytes space
for argument.
This CL fixes it.
Updates #15365.
Change-Id: Ic65d55283a6aa8a7861d7a3fbc7b63c35785eeec
Reviewed-on: https://go-review.googlesource.com/24909
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/gc/ssa.go | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go index ed6a755439..088018f6c0 100644 --- a/src/cmd/compile/internal/gc/ssa.go +++ b/src/cmd/compile/internal/gc/ssa.go @@ -3013,7 +3013,7 @@ func (s *state) rtcall(fn *Node, returns bool, results []*Type, args ...*ssa.Val if !returns { b.Kind = ssa.BlockExit b.SetControl(call) - call.AuxInt = off + call.AuxInt = off - Ctxt.FixedFrameSize() if len(results) > 0 { Fatalf("panic call can't have results") } |