X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/1b07c4f340465551b7d12c3be3bcecd258a3c32d..1519ef6617fd7351bd40026b9eeb47c7f7f42234:/base/dispatch-x86ish.S

diff --git a/base/dispatch-x86ish.S b/base/dispatch-x86ish.S
index b3b6d1cb..57d8d32b 100644
--- a/base/dispatch-x86ish.S
+++ b/base/dispatch-x86ish.S
@@ -158,10 +158,11 @@ ENDFUNC
 /// Checking `rdrand'.
 
 FUNC(dispatch_x86ish_rdrand)
-	// Enter with two arguments: a code OP requesting `rdrand' (0), and a
-	// pointer X_OUT to a 32-bit word.  Try to generate a random word
-	// using the requested instruction.  If successful, set *X_OUT to the
-	// generated word, and return zero; otherwise, return -1.
+	// Enter with two arguments: a code OP requesting either `rdrand' (0)
+	// or `rdseed' (1), and a pointer X_OUT to a 32-bit word.  Try to
+	// generate a random word using the requested instruction'.  If
+	// successful, set *X_OUT to the generated word, and return zero;
+	// otherwise, return -1.
 
 #if CPUFAM_X86
 #  define OP eax
@@ -182,13 +183,22 @@ FUNC(dispatch_x86ish_rdrand)
 #endif
   endprologue
 
+	cmp	OP, 0
 	mov	COUNT, 16		// fairly persistent
+	jne	1f
+
 0:	rdrand	eax
 	jc	9f
 	dec	COUNT
 	jnz	0b
 	jmp	8f
 
+1:	rdseed	eax
+	jc	9f
+	dec	COUNT
+	jnz	1b
+	jmp	8f
+
 	// Failed to come up with a random value.
 8:	mov	eax, -1
 	ret