diff options
Diffstat (limited to 'src/x86_64/tsc-x86_64.s')
| -rw-r--r-- | src/x86_64/tsc-x86_64.s | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/x86_64/tsc-x86_64.s b/src/x86_64/tsc-x86_64.s new file mode 100644 index 0000000..da33191 --- /dev/null +++ b/src/x86_64/tsc-x86_64.s @@ -0,0 +1,40 @@ +/************************************************************************* + * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com> * + * * + * This file is part of The Sandglass Library. * + * * + * The Sandglass Library is free software; you can redistribute it * + * and/or modify it under the terms of the GNU Lesser General Public * + * License as published by the Free Software Foundation; either version * + * 3 of the License, or (at your option) any later version. * + * * + * The Sandglass Library is distributed in the hope that it will be * + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * + * Lesser General Public License for more details. * + * * + * You should have received a copy of the GNU Lesser General Public * + * License along with this program. If not, see * + * <http://www.gnu.org/licenses/>. * + *************************************************************************/ + +/* + * Return the time stamp counter, and serialize the instruction + */ + + .text +/* long sandglass_get_tsc(); */ +.globl sandglass_get_tsc + .type sandglass_get_tsc, @function +ticks: + movq %rbx, %rdi /* Callee-save register, clobbered by cpuid */ + cpuid /* Serialize */ + rdtsc /* Read time stamp counter */ + shlq $32, %rdx + orq %rdx, %rax + movq %rax, %rsi + cpuid /* Serialize again */ + movq %rsi, %rax + movq %rdi, %rbx + ret + .size sandglass_get_tsc, .-sandglass_get_tsc |