diff options
Diffstat (limited to 'src/x86_64/tsc-x86_64.s')
| -rw-r--r-- | src/x86_64/tsc-x86_64.s | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/x86_64/tsc-x86_64.s b/src/x86_64/tsc-x86_64.s index c585719..52f02c2 100644 --- a/src/x86_64/tsc-x86_64.s +++ b/src/x86_64/tsc-x86_64.s @@ -38,3 +38,20 @@ sandglass_get_tsc: movq %rdi, %rbx ret .size sandglass_get_tsc, .-sandglass_get_tsc + +/* + * Return the granularity of the TSC + */ + +/* unsigned int sandglass_tsc_loops(); */ +.globl sandglass_tsc_loops + .type sandglass_tsc_loops, @function +sandglass_tsc_loops: + rdtsc /* Read time stamp counter */ + movl %eax, %ecx +.Lrdtsc: + rdtsc /* Read counter again */ + subl %ecx, %eax + jz .Lrdtsc /* If we got the same value, try again */ + ret + .size sandglass_tsc_loops, .-sandglass_tsc_loops |