diff -r 2f2f54ed12ce -r 6af0a709d52b src/os_cpu/solaris_sparc/vm/vm_version_solaris_sparc.cpp
--- a/src/os_cpu/solaris_sparc/vm/vm_version_solaris_sparc.cpp	Tue Mar 10 08:52:16 2009 -0700
+++ b/src/os_cpu/solaris_sparc/vm/vm_version_solaris_sparc.cpp	Wed Mar 11 14:16:13 2009 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2006-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,58 +25,106 @@
 # include "incls/_precompiled.incl"
 # include "incls/_vm_version_solaris_sparc.cpp.incl"
 
+# include <sys/auxv.h>
+# include <sys/auxv_SPARC.h>
 # include <sys/systeminfo.h>
 
+// We need to keep these here as long as we have to build on Solaris
+// versions before 10.
+#ifndef SI_ARCHITECTURE_32
+#define SI_ARCHITECTURE_32      516     /* basic 32-bit SI_ARCHITECTURE */
+#endif
+
+#ifndef SI_ARCHITECTURE_64
+#define SI_ARCHITECTURE_64      517     /* basic 64-bit SI_ARCHITECTURE */
+#endif
+
+static void do_sysinfo(int si, const char* string, int* features, int mask) {
+  char   tmp;
+  size_t bufsize = sysinfo(si, &tmp, 1);
+
+  // All SI defines used below must be supported.
+  guarantee(bufsize != -1, "must be supported");
+
+  char* buf = (char*) malloc(bufsize);
+
+  if (buf == NULL)
+    return;
+
+  if (sysinfo(si, buf, bufsize) == bufsize) {
+    // Compare the string.
+    if (strcmp(buf, string) == 0) {
+      *features |= mask;
+    }
+  }
+
+  free(buf);
+}
+
 int VM_Version::platform_features(int features) {
-  // We determine what sort of hardware we have via sysinfo(SI_ISALIST, ...).
-  // This isn't the best of all possible ways because there's not enough
-  // detail in the isa list it returns, but it's a bit less arcane than
-  // generating assembly code and an illegal instruction handler.  We used
-  // to generate a getpsr trap, but that's even more arcane.
-  //
-  // Another possibility would be to use sysinfo(SI_PLATFORM, ...), but
-  // that would require more knowledge here than is wise.
+  // getisax(2), SI_ARCHITECTURE_32, and SI_ARCHITECTURE_64 are
+  // supported on Solaris 10 and later.
+  if (os::Solaris::supports_getisax()) {
+#ifndef PRODUCT
+    if (PrintMiscellaneous && Verbose)
+      tty->print_cr("getisax(2) supported.");
+#endif
 
-  // isalist spec via 'man isalist' as of 01-Aug-2001
+    // Check 32-bit architecture.
+    do_sysinfo(SI_ARCHITECTURE_32, "sparc", &features, v8_instructions_m);
 
-  char   tmp;
-  size_t bufsize  = sysinfo(SI_ISALIST, &tmp, 1);
-  char*  buf      = (char*)malloc(bufsize);
+    // Check 64-bit architecture.
+    do_sysinfo(SI_ARCHITECTURE_64, "sparcv9", &features, generic_v9_m);
 
-  if (buf != NULL) {
-    if (sysinfo(SI_ISALIST, buf, bufsize) == bufsize) {
-      // Figure out what kind of sparc we have
-      char *sparc_string = strstr(buf, "sparc");
-      if (sparc_string != NULL) {            features |= v8_instructions_m;
-        if (sparc_string[5] == 'v') {
-          if (sparc_string[6] == '8') {
-            if (sparc_string[7] == '-')      features |= hardware_int_muldiv_m;
-            else if (sparc_string[7] == 'p') features |= generic_v9_m;
-            else                      features |= generic_v8_m;
-          } else if (sparc_string[6] == '9') features |= generic_v9_m;
+    // Extract valid instruction set extensions.
+    uint_t av;
+    uint_t avn = os::Solaris::getisax(&av, 1);
+    assert(avn == 1, "should only return one av");
+
+    if (av & AV_SPARC_MUL32)  features |= hardware_mul32_m;
+    if (av & AV_SPARC_DIV32)  features |= hardware_div32_m;
+    if (av & AV_SPARC_FSMULD) features |= hardware_fsmuld_m;
+    if (av & AV_SPARC_V8PLUS) features |= v9_instructions_m;
+    if (av & AV_SPARC_VIS)    features |= vis1_instructions_m;
+    if (av & AV_SPARC_VIS2)   features |= vis2_instructions_m;
+  } else {
+    // getisax(2) failed, use the old legacy code.
+#ifndef PRODUCT
+    if (PrintMiscellaneous && Verbose)
+      tty->print_cr("getisax(2) not supported.");
+#endif
+
+    char   tmp;
+    size_t bufsize = sysinfo(SI_ISALIST, &tmp, 1);
+    char*  buf     = (char*) malloc(bufsize);
+
+    if (buf != NULL) {
+      if (sysinfo(SI_ISALIST, buf, bufsize) == bufsize) {
+        // Figure out what kind of sparc we have
+        char *sparc_string = strstr(buf, "sparc");
+        if (sparc_string != NULL) {              features |= v8_instructions_m;
+          if (sparc_string[5] == 'v') {
+            if (sparc_string[6] == '8') {
+              if (sparc_string[7] == '-') {      features |= hardware_mul32_m;
+                                                 features |= hardware_div32_m;
+              } else if (sparc_string[7] == 'p') features |= generic_v9_m;
+              else                               features |= generic_v8_m;
+            } else if (sparc_string[6] == '9')   features |= generic_v9_m;
+          }
+        }
+
+        // Check for visualization instructions
+        char *vis = strstr(buf, "vis");
+        if (vis != NULL) {                       features |= vis1_instructions_m;
+          if (vis[3] == '2')                     features |= vis2_instructions_m;
         }
       }
-
-      // Check for visualization instructions
-      char *vis = strstr(buf, "vis");
-      if (vis != NULL) {              features |= vis1_instructions_m;
-        if (vis[3] == '2')            features |= vis2_instructions_m;
-      }
+      free(buf);
     }
-    free(buf);
   }
 
-  bufsize = sysinfo(SI_MACHINE, &tmp, 1);
-  buf     = (char*)malloc(bufsize);
-
-  if (buf != NULL) {
-    if (sysinfo(SI_MACHINE, buf, bufsize) == bufsize) {
-      if (strstr(buf, "sun4v") != NULL) {
-        features |= sun4v_m;
-      }
-    }
-    free(buf);
-  }
+  // Determine the machine type.
+  do_sysinfo(SI_MACHINE, "sun4v", &features, sun4v_m);
 
   return features;
 }