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Avoid cpuid instructions in cache info discovery.

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When multiarch is enabled we have this information stored.  Use it.
This commit is contained in:
Ulrich Drepper 2009-07-23 14:03:53 -07:00
parent 3e9099b4f6
commit b2509a1e38
2 changed files with 35 additions and 19 deletions
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4
ChangeLog
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@ -1,5 +1,9 @@
2009-07-23 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/cacheinfo.c [USE_MULTIARCH]: Rearrange code to
avoid additional cpuid instructions. Most of the information is
stored somewhere.
* sysdeps/unix/sysv/linux/i386/sysconf.c (intel_02_known): Add more
cache descriptors.
* sysdeps/x86_64/cacheinfo.c (intel_02_known): Likewise.

50
sysdeps/x86_64/cacheinfo.c
View File

@ -25,6 +25,17 @@
#ifdef USE_MULTIARCH
# include "multiarch/init-arch.h"
# define is_intel __cpu_features.kind == arch_kind_intel
# define is_amd __cpu_features.kind == arch_kind_amd
# define max_cpuid __cpu_features.max_cpuid
#else
/* This spells out "GenuineIntel". */
# define is_intel \
ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69
/* This spells out "AuthenticAMD". */
# define is_amd \
ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65
#endif
static const struct intel_02_cache_info
@ -155,6 +166,12 @@ intel_check_word (int name, unsigned int value, bool *has_level_2,
/* Intel reused this value. For family 15, model 6 it
specifies the 3rd level cache. Otherwise the 2nd
level cache. */
unsigned int family;
unsigned int model;
#ifdef USE_MULTIARCH
family = __cpu_features.family;
model = __cpu_features.model;
#else
unsigned int eax;
unsigned int ebx;
unsigned int ecx;
@ -163,9 +180,10 @@ intel_check_word (int name, unsigned int value, bool *has_level_2,
: "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx)
: "0" (1));
unsigned int family = ((eax >> 20) & 0xff) + ((eax >> 8) & 0xf);
unsigned int model = ((((eax >>16) & 0xf) << 4)
+ ((eax >> 4) & 0xf));
family = ((eax >> 20) & 0xff) + ((eax >> 8) & 0xf);
model = (((eax >>16) & 0xf) << 4) + ((eax >> 4) & 0xf);
#endif
if (family == 15 && model == 6)
{
/* The level 3 cache is encoded for this model like
@ -397,21 +415,24 @@ long int
attribute_hidden
__cache_sysconf (int name)
{
#ifdef USE_MULTIARCH
if (__cpu_features.kind == arch_kind_unknown)
__init_cpu_features ();
#else
/* Find out what brand of processor. */
unsigned int eax;
unsigned int max_cpuid;
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
asm volatile ("cpuid"
: "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx)
: "=a" (max_cpuid), "=b" (ebx), "=c" (ecx), "=d" (edx)
: "0" (0));
#endif
/* This spells out "GenuineIntel". */
if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
return handle_intel (name, eax);
if (is_intel)
return handle_intel (name, max_cpuid);
/* This spells out "AuthenticAMD". */
if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
if (is_amd)
return handle_amd (name);
// XXX Fill in more vendors.
@ -460,20 +481,11 @@ init_cacheinfo (void)
#ifdef USE_MULTIARCH
if (__cpu_features.kind == arch_kind_unknown)
__init_cpu_features ();
# define is_intel __cpu_features.kind == arch_kind_intel
# define is_amd __cpu_features.kind == arch_kind_amd
# define max_cpuid __cpu_features.max_cpuid
#else
int max_cpuid;
asm volatile ("cpuid"
: "=a" (max_cpuid), "=b" (ebx), "=c" (ecx), "=d" (edx)
: "0" (0));
/* This spells out "GenuineIntel". */
# define is_intel \
ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69
/* This spells out "AuthenticAMD". */
# define is_amd \
ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65
#endif
if (is_intel)