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| author | Tavian Barnes <tavianator@gmail.com> | 2009-09-21 03:48:30 +0000 |
|---|---|---|
| committer | Tavian Barnes <tavianator@gmail.com> | 2009-09-21 03:48:30 +0000 |
| commit | 9bfbf7832dd379a4a006d236fbeda27be7e13928 (patch) | |
| tree | a7311df043b6f92af247efb9619ffe829e1d7c0e /src/x86_64/tsc-x86_64.s | |
| parent | 5f446ac4c9d98c7819ff836c0666c798f351ae2c (diff) | |
| download | libsandglass-9bfbf7832dd379a4a006d236fbeda27be7e13928.tar.xz | |
Make `cpuid' do the same thing for every sandglass_get_tsc() call.
Diffstat (limited to 'src/x86_64/tsc-x86_64.s')
| -rw-r--r-- | src/x86_64/tsc-x86_64.s | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/x86_64/tsc-x86_64.s b/src/x86_64/tsc-x86_64.s index 52f02c2..e710891 100644 --- a/src/x86_64/tsc-x86_64.s +++ b/src/x86_64/tsc-x86_64.s @@ -28,11 +28,13 @@ .type sandglass_get_tsc, @function sandglass_get_tsc: movq %rbx, %rdi /* Callee-save register, clobbered by cpuid */ + xorl %eax, %eax /* Make cpuid do a consistent operation */ cpuid /* Serialize */ rdtsc /* Read time stamp counter */ shlq $32, %rdx orq %rdx, %rax movq %rax, %rsi + xorl %eax, %eax cpuid /* Serialize again */ movq %rsi, %rax movq %rdi, %rbx |