The GODEBUG environment variable can be used to disable usage of
specific processor features of Go programs that use the sys/cpu package.
This is useful for testing and benchmarking different code paths that
are guarded by sys/cpu variable checks.
Use of processor features can not be enabled through GODEBUG.
To disable usage of AVX and SSE41 cpu features on GOARCH amd64 use:
GODEBUG=cpu.avx=off,cpu.sse41=off
The special "all" option can be used to disable all options:
GODEBUG=all=off
This aligns the support of GODEBUG for sys/cpu with existing support
for GODEBUG in the Go standard library package internal/cpu.
Fixesgolang/go#33963
Change-Id: I618b71af397bf06c57a49b2a300d032a16d05664
Reviewed-on: https://go-review.googlesource.com/c/sys/+/245237
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
On Android /proc/self/auxv is not readable, leading to a panic in init.
Instead of panic'ing in this case, introduce the Initialized global bool
to report whether the CPU features were initialized i.e. /proc/self/auxv
was successfullly read.
Fixesgolang/go#30413
Change-Id: Ib520f202990614a76bceb0bf9d19a88eadd13e10
Reviewed-on: https://go-review.googlesource.com/c/164057
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
