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8005522: use fast-string instructions on x86 for zeroing

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Use 'rep stosb' instead of 'rep stosq' when fast-string operations are available.

Reviewed-by: twisti, roland
This commit is contained in:
Vladimir Kozlov 2013-01-03 15:09:55 -08:00
parent 73d6d417be
commit cfcd28fd9d
10 changed files with 95 additions and 22 deletions
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11
hotspot/src/cpu/x86/vm/vm_version_x86.hpp
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@ -204,7 +204,8 @@ public:
avx2 : 1,
: 2,
bmi2 : 1,
: 23;
erms : 1,
: 22;
} bits;
};
@ -247,7 +248,8 @@ protected:
CPU_TSCINV = (1 << 16),
CPU_AVX = (1 << 17),
CPU_AVX2 = (1 << 18),
CPU_AES = (1 << 19)
CPU_AES = (1 << 19),
CPU_ERMS = (1 << 20) // enhanced 'rep movsb/stosb' instructions
} cpuFeatureFlags;
enum {
@ -425,6 +427,8 @@ protected:
result |= CPU_TSCINV;
if (_cpuid_info.std_cpuid1_ecx.bits.aes != 0)
result |= CPU_AES;
if (_cpuid_info.sef_cpuid7_ebx.bits.erms != 0)
result |= CPU_ERMS;
// AMD features.
if (is_amd()) {
@ -489,7 +493,7 @@ public:
return (_cpuid_info.std_max_function >= 0xB) &&
// eax[4:0] | ebx[0:15] == 0 indicates invalid topology level.
// Some cpus have max cpuid >= 0xB but do not support processor topology.
((_cpuid_info.tpl_cpuidB0_eax & 0x1f | _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus) != 0);
(((_cpuid_info.tpl_cpuidB0_eax & 0x1f) | _cpuid_info.tpl_cpuidB0_ebx.bits.logical_cpus) != 0);
}
static uint cores_per_cpu() {
@ -550,6 +554,7 @@ public:
static bool supports_avx2() { return (_cpuFeatures & CPU_AVX2) != 0; }
static bool supports_tsc() { return (_cpuFeatures & CPU_TSC) != 0; }
static bool supports_aes() { return (_cpuFeatures & CPU_AES) != 0; }
static bool supports_erms() { return (_cpuFeatures & CPU_ERMS) != 0; }
// Intel features
static bool is_intel_family_core() { return is_intel() &&