base/dispatch.c, etc.: Replace inline assembler for the `rdrand' fix.

[catacomb] / base / dispatch.c

diff --git a/base/dispatch.c b/base/dispatch.c
index 459302f..65ea2d2 100644 (file)
--- a/base/dispatch.c
+++ b/base/dispatch.c
@@ -54,6 +54,7 @@
 struct cpuid { unsigned a, b, c, d; };
 extern int dispatch_x86ish_cpuid(struct cpuid *, unsigned a, unsigned c);
 extern int dispatch_x86ish_xmmregisters_p(void);
+extern int dispatch_x86ish_rdrand(unsigned *);
 
 static void cpuid(struct cpuid *cc, unsigned a, unsigned c)
 {
@@ -110,25 +111,6 @@ static int xmm_registers_available_p(void)
  *             that it's already been verified to be safe to issue.
  */
 
-#ifdef __GNUC__
-static int rdrand(unsigned *x)
-{
-  int i, rc;
-  unsigned _t;
-
-  i = 16;
-  __asm__ ("" : "=g" (_t));
-  __asm__ ("0: rdrand %2; jc 1f; decl %1; jnz 0b\n"
-          "mov $-1, %0; jmp 9f\n"
-          "1: movl %2, (%3); xorl %0, %0\n"
-          "9:"
-          : "=r" (rc), "+r" (i), "+r" (_t)
-          : "r" (x)
-          : "cc");
-  return (rc);
-}
-#endif
-
 static int rdrand_works_p(void)
 {
   unsigned ref, x, i;
@@ -137,9 +119,9 @@ static int rdrand_works_p(void)
    * will fail with probability %$2^{-128}$% with a truly random generator,
    * which seems fair enough.
    */
-  if (rdrand(&ref)) goto fail;
+  if (dispatch_x86ish_rdrand(&ref)) goto fail;
   for (i = 0; i < 4; i++) {
-    if (rdrand(&x)) goto fail;
+    if (dispatch_x86ish_rdrand(&x)) goto fail;
     if (x != ref) goto not_stuck;
   }
   dispatch_debug("RDRAND always returns 0x%08x!", ref);