--- a/hotspot/src/cpu/x86/vm/vm_version_x86.cpp Tue May 05 11:02:10 2009 -0700
+++ b/hotspot/src/cpu/x86/vm/vm_version_x86.cpp Wed May 06 00:27:52 2009 -0700
@@ -284,7 +284,7 @@
}
char buf[256];
- jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+ jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
cores_per_cpu(), threads_per_core(),
cpu_family(), _model, _stepping,
(supports_cmov() ? ", cmov" : ""),
@@ -301,6 +301,7 @@
(supports_mmx_ext() ? ", mmxext" : ""),
(supports_3dnow() ? ", 3dnow" : ""),
(supports_3dnow2() ? ", 3dnowext" : ""),
+ (supports_lzcnt() ? ", lzcnt": ""),
(supports_sse4a() ? ", sse4a": ""),
(supports_ht() ? ", ht": ""));
_features_str = strdup(buf);
@@ -364,6 +365,13 @@
UseXmmI2D = false;
}
}
+
+ // Use count leading zeros count instruction if available.
+ if (supports_lzcnt()) {
+ if (FLAG_IS_DEFAULT(UseCountLeadingZerosInstruction)) {
+ UseCountLeadingZerosInstruction = true;
+ }
+ }
}
if( is_intel() ) { // Intel cpus specific settings