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authorH.J. Lu <hjl.tools@gmail.com>2018-10-21 00:37:11 -0700
committerH.J. Lu <hjl.tools@gmail.com>2018-10-21 00:37:29 -0700
commit2dd8e58cc533ee840d37725b11bc0dc0308a5dc0 (patch)
tree09450906254b26f1104371eb9940f50391ec21cd
parentd0a74159792477e5922f53fa2aa6d58eb8265a14 (diff)
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x86: Don't include <x86intrin.h>
Use __builtin_ia32_rdtsc directly since including <x86intrin.h> makes building glibc very slow. On Intel Core i5-6260U, this patch reduces x86-64 build time from 8 minutes 33 seconds to 3 minutes 48 seconds with "make -j4" and GCC 8.2.1. * sysdeps/x86/hp-timing.h: Don't include <x86intrin.h>. (HP_TIMING_NOW): Replace _rdtsc with __builtin_ia32_rdtsc.
-rw-r--r--ChangeLog5
-rw-r--r--sysdeps/x86/hp-timing.h9
2 files changed, 10 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog
index eb1b0dbb1c..c3fbad184e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-10-21 H.J. Lu <hongjiu.lu@intel.com>
+
+ * sysdeps/x86/hp-timing.h: Don't include <x86intrin.h>.
+ (HP_TIMING_NOW): Replace _rdtsc with __builtin_ia32_rdtsc.
+
2018-10-19 Joseph Myers <joseph@codesourcery.com>
[BZ #23794]
diff --git a/sysdeps/x86/hp-timing.h b/sysdeps/x86/hp-timing.h
index 1c20e9d828..77a1360748 100644
--- a/sysdeps/x86/hp-timing.h
+++ b/sysdeps/x86/hp-timing.h
@@ -22,8 +22,6 @@
#include <isa.h>
#if MINIMUM_ISA == 686 || MINIMUM_ISA == 8664
-# include <x86intrin.h>
-
/* We always assume having the timestamp register. */
# define HP_TIMING_AVAIL (1)
# define HP_SMALL_TIMING_AVAIL (1)
@@ -38,8 +36,11 @@ typedef unsigned long long int hp_timing_t;
might not be 100% accurate since there might be some more instructions
running in this moment. This could be changed by using a barrier like
'cpuid' right before the `rdtsc' instruciton. But we are not interested
- in accurate clock cycles here so we don't do this. */
-# define HP_TIMING_NOW(Var) ((Var) = _rdtsc ())
+ in accurate clock cycles here so we don't do this.
+
+ NB: Use __builtin_ia32_rdtsc directly since including <x86intrin.h>
+ makes building glibc very slow. */
+# define HP_TIMING_NOW(Var) ((Var) = __builtin_ia32_rdtsc ())
# include <hp-timing-common.h>
#else