From b7a2d413a3f710f14accedf185c93bfb63d24fd0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20M=C3=B6hrmann?= Date: Tue, 20 Oct 2020 09:56:14 +0200 Subject: testing: print cpu type as label for benchmarks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Supports 386 and amd64 architectures on all operating systems. Example output: $ go test -bench=.* goos: darwin goarch: amd64 pkg: strconv cpu: Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz BenchmarkAtof64Decimal-4 24431032 46.8 ns/op ... As the displayed CPU information is only used for information purposes it is lazily initialized when needed using the new internal/sysinfo package. This allows internal/cpu to stay without dependencies and avoid initialization costs when the CPU information is not needed as the new code to query the CPU name in internal/cpu can be dead code eliminated if not used. Fixes #39214 Change-Id: I77ae5c5d2fed6b28fa78dd45075f9f0a6a7f1bfd Reviewed-on: https://go-review.googlesource.com/c/go/+/263804 Trust: Martin Möhrmann Reviewed-by: Keith Randall --- src/internal/cpu/cpu_x86.go | 49 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'src/internal/cpu/cpu_x86.go') diff --git a/src/internal/cpu/cpu_x86.go b/src/internal/cpu/cpu_x86.go index da6cf67258..fb414adaf8 100644 --- a/src/internal/cpu/cpu_x86.go +++ b/src/internal/cpu/cpu_x86.go @@ -38,6 +38,8 @@ const ( cpuid_ADX = 1 << 19 ) +var maxExtendedFunctionInformation uint32 + func doinit() { options = []option{ {Name: "adx", Feature: &X86.HasADX}, @@ -65,6 +67,8 @@ func doinit() { return } + maxExtendedFunctionInformation, _, _, _ = cpuid(0x80000000, 0) + _, _, ecx1, edx1 := cpuid(1, 0) X86.HasSSE2 = isSet(edx1, cpuid_SSE2) @@ -103,3 +107,48 @@ func doinit() { func isSet(hwc uint32, value uint32) bool { return hwc&value != 0 } + +// Name returns the CPU name given by the vendor. +// If the CPU name can not be determined an +// empty string is returned. +func Name() string { + if maxExtendedFunctionInformation < 0x80000004 { + return "" + } + + data := make([]byte, 0, 3*4*4) + + var eax, ebx, ecx, edx uint32 + eax, ebx, ecx, edx = cpuid(0x80000002, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + eax, ebx, ecx, edx = cpuid(0x80000003, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + eax, ebx, ecx, edx = cpuid(0x80000004, 0) + data = appendBytes(data, eax, ebx, ecx, edx) + + // Trim leading spaces. + for len(data) > 0 && data[0] == ' ' { + data = data[1:] + } + + // Trim tail after and including the first null byte. + for i, c := range data { + if c == '\x00' { + data = data[:i] + break + } + } + + return string(data) +} + +func appendBytes(b []byte, args ...uint32) []byte { + for _, arg := range args { + b = append(b, + byte((arg >> 0)), + byte((arg >> 8)), + byte((arg >> 16)), + byte((arg >> 24))) + } + return b +} -- cgit v1.2.1