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| author | Cherry Zhang <cherryyz@google.com> | 2020-08-17 19:06:19 -0400 |
|---|---|---|
| committer | Dmitri Shuralyov <dmitshur@golang.org> | 2020-09-03 14:49:02 +0000 |
| commit | f50cde9a704542faf6c499e1a69c6bdd6e451f30 (patch) | |
| tree | 99fda76fb8537a7dd470ad69ebba432d74e25920 /src/cmd/compile/internal/ssa/opGen.go | |
| parent | b616f745ef6eb14daeb1d7d9b41a2908835bc3fd (diff) | |
| download | go-f50cde9a704542faf6c499e1a69c6bdd6e451f30.tar.gz go-f50cde9a704542faf6c499e1a69c6bdd6e451f30.zip | |
[release-branch.go1.15] cmd/compile, runtime: mark R12 clobbered for write barrier call on PPC64
When external linking, for large binaries, the external linker
may insert a trampoline for the write barrier call, which looks
0000000005a98cc8 <__long_branch_runtime.gcWriteBarrier>:
5a98cc8: 86 01 82 3d addis r12,r2,390
5a98ccc: d8 bd 8c e9 ld r12,-16936(r12)
5a98cd0: a6 03 89 7d mtctr r12
5a98cd4: 20 04 80 4e bctr
It clobbers R12 (and CTR, which is never live across a call).
As at compile time we don't know whether the binary is big and
what link mode will be used, I think we need to mark R12 as
clobbered for write barrier call. For extra safety (future-proof)
we mark caller-saved register that cannot be used for function
arguments, which includes R11, as potentially clobbered as well.
Updates #40851.
Fixes #40868.
Change-Id: Iedd901c5072f1127cc59b0a48cfeb4aaec81b519
Reviewed-on: https://go-review.googlesource.com/c/go/+/248917
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
(cherry picked from commit b58d29741650c7bf10b17f455666e2727e1cdd2e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/249019
Diffstat (limited to 'src/cmd/compile/internal/ssa/opGen.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/opGen.go | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go index 9efa1bfcc4..8a27c4bb2e 100644 --- a/src/cmd/compile/internal/ssa/opGen.go +++ b/src/cmd/compile/internal/ssa/opGen.go @@ -26885,7 +26885,7 @@ var opcodeTable = [...]opInfo{ {0, 1048576}, // R20 {1, 2097152}, // R21 }, - clobbers: 576460746931503104, // R16 R17 R18 R19 R22 R23 R24 R25 R26 R27 R28 R29 R31 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 + clobbers: 576460746931312640, // R11 R12 R18 R19 R22 R23 R24 R25 R26 R27 R28 R29 R31 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15 F16 F17 F18 F19 F20 F21 F22 F23 F24 F25 F26 }, }, { |