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| author | Keith Randall <khr@golang.org> | 2023-01-26 17:25:44 -0800 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2023-01-30 14:56:56 +0000 |
| commit | ee5ce77c62483933ae4d5dbdbcbadf6f82dd3f6c (patch) | |
| tree | 6c7c429a14a56a5a6703e701da5b2b5cb5138d39 /src/cmd/internal | |
| parent | 49520907394c0a1060b51dc4a5d5ce1ac470a5f1 (diff) | |
| download | go-ee5ce77c62483933ae4d5dbdbcbadf6f82dd3f6c.tar.xz | |
cmd/asm: reject avx512 .Z instructions without a mask register
Zeroing requires a non-K0 mask register be specified.
(gcc enforces this when assembling.)
The non-K0 restriction is already handled by the Yknot0 restriction.
But if the mask register is missing altogether, we misassemble the
instruction.
Fixes #57952
Not sure if this is really worth mentioning in the release notes,
but just in case I'll mark it.
RELNOTE=yes
Change-Id: I8f05d3155503f1f16d1b5ab9d67686fe5b64dfea
Reviewed-on: https://go-review.googlesource.com/c/go/+/463229
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Илья Токарь <tocarip@gmail.com>
Reviewed-by: Iskander Sharipov <quasilyte@gmail.com>
Diffstat (limited to 'src/cmd/internal')
| -rw-r--r-- | src/cmd/internal/obj/x86/asm6.go | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go index de08b42ab5..b441964492 100644 --- a/src/cmd/internal/obj/x86/asm6.go +++ b/src/cmd/internal/obj/x86/asm6.go @@ -4070,6 +4070,16 @@ func (ab *AsmBuf) asmevex(ctxt *obj.Link, p *obj.Prog, rm, v, r, k *obj.Addr) { if !evex.ZeroingEnabled() { ctxt.Diag("unsupported zeroing: %v", p) } + if k == nil { + // When you request zeroing you must specify a mask register. + // See issue 57952. + ctxt.Diag("mask register must be specified for .Z instructions: %v", p) + } else if k.Reg == REG_K0 { + // The mask register must not be K0. That restriction is already + // handled by the Yknot0 restriction in the opcode tables, so we + // won't ever reach here. But put something sensible here just in case. + ctxt.Diag("mask register must not be K0 for .Z instructions: %v", p) + } evexZ = 1 } switch { |