X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/dc2adc883524babe0ebec62d8f85372ef18bfd7a..1519ef6617fd7351bd40026b9eeb47c7f7f42234:/rand/rand-x86ish.S

diff --git a/rand/rand-x86ish.S b/rand/rand-x86ish.S
index 70907feb..399ccb1d 100644
--- a/rand/rand-x86ish.S
+++ b/rand/rand-x86ish.S
@@ -54,7 +54,8 @@ FUNC(rand_quick_x86ish_rdrand)
 
 #if CPUFAM_X86
 	mov	edx, [SP + 4]
-	stalloc	28
+	push	ebx
+	stalloc	24
 #endif
 #if CPUFAM_AMD64 && ABI_SYSV
 	stalloc	8
@@ -74,10 +75,40 @@ FUNC(rand_quick_x86ish_rdrand)
 	// Failed.
 	mov	eax, -1
 	jmp	9f
+ENDFUNC
+
+FUNC(rand_quick_x86ish_rdseed)
+	// Enter with a pointer to the random context in the first argument.
+	// Return zero on success, or -1 on error.
+
+#if CPUFAM_X86
+	mov	edx, [SP + 4]
+	push	ebx
+	stalloc	24
+#endif
+#if CPUFAM_AMD64 && ABI_SYSV
+	stalloc	8
+#endif
+#if CPUFAM_AMD64 && ABI_WIN
+	stalloc	40
+#endif
+  endprologue
+
+	// Try to fetch a random number.
+	mov	COUNT, 16
+0:	rdseed	AX
+	jc	1f
+	dec	COUNT
+	jnz	0b
+
+	// Failed.
+	mov	eax, -1
+	jmp	9f
 
 	// Success.
 1:
 #if CPUFAM_X86
+	ldgot	ebx
 	mov	[SP + 16], AX
 	lea	ecx, [SP + 16]
 	mov	dword ptr [SP + 12], 32
@@ -103,7 +134,8 @@ FUNC(rand_quick_x86ish_rdrand)
 	// Done.
 9:
 #if CPUFAM_X86
-	stfree	28
+	stfree	24
+	pop	ebx
 #endif
 #if CPUFAM_AMD64 && ABI_SYSV
 	stfree	8