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| author | Cherry Zhang <cherryyz@google.com> | 2020-02-25 20:30:37 -0500 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2020-02-26 01:52:42 +0000 |
| commit | c46ffdd2eca339918ed30b6ba9d4715ba769d35d (patch) | |
| tree | 02888c9df18e9afafd0a59ad94b63761a2a01ba8 /src/runtime/mkpreempt.go | |
| parent | 089e482b3dd2026178c8ee5b90d9aadb6bf81239 (diff) | |
| download | go-c46ffdd2eca339918ed30b6ba9d4715ba769d35d.tar.gz go-c46ffdd2eca339918ed30b6ba9d4715ba769d35d.zip | |
runtime: guard VZEROUPPER on CPU feature
In CL 219131 we inserted a VZEROUPPER instruction on darwin/amd64.
The instruction is not available on pre-AVX machines. Guard it
with CPU feature.
Fixes #37459.
Change-Id: I9a064df277d091be4ee594eda5c7fd8ee323102b
Reviewed-on: https://go-review.googlesource.com/c/go/+/221057
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime/mkpreempt.go')
| -rw-r--r-- | src/runtime/mkpreempt.go | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/runtime/mkpreempt.go b/src/runtime/mkpreempt.go index 31b6f5cbac..c26406e55f 100644 --- a/src/runtime/mkpreempt.go +++ b/src/runtime/mkpreempt.go @@ -244,23 +244,26 @@ func genAMD64() { // TODO: MXCSR register? + p("PUSHQ BP") + p("MOVQ SP, BP") + p("// Save flags before clobbering them") + p("PUSHFQ") + p("// obj doesn't understand ADD/SUB on SP, but does understand ADJSP") + p("ADJSP $%d", l.stack) + p("// But vet doesn't know ADJSP, so suppress vet stack checking") + p("NOP SP") + // Apparently, the signal handling code path in darwin kernel leaves // the upper bits of Y registers in a dirty state, which causes // many SSE operations (128-bit and narrower) become much slower. // Clear the upper bits to get to a clean state. See issue #37174. // It is safe here as Go code don't use the upper bits of Y registers. p("#ifdef GOOS_darwin") + p("CMPB internal∕cpu·X86+const_offsetX86HasAVX(SB), $0") + p("JE 2(PC)") p("VZEROUPPER") p("#endif") - p("PUSHQ BP") - p("MOVQ SP, BP") - p("// Save flags before clobbering them") - p("PUSHFQ") - p("// obj doesn't understand ADD/SUB on SP, but does understand ADJSP") - p("ADJSP $%d", l.stack) - p("// But vet doesn't know ADJSP, so suppress vet stack checking") - p("NOP SP") l.save() p("CALL ·asyncPreempt2(SB)") l.restore() |