Module Name:    src
Committed By:   christos
Date:           Thu Sep 29 22:46:00 UTC 2011

Modified Files:
        src/lib/libc/arch/i386/gen: flt_rounds.S

Log Message:
add a simpler version


To generate a diff of this commit:
cvs rdiff -u -r1.6 -r1.7 src/lib/libc/arch/i386/gen/flt_rounds.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/lib/libc/arch/i386/gen/flt_rounds.S
diff -u src/lib/libc/arch/i386/gen/flt_rounds.S:1.6 src/lib/libc/arch/i386/gen/flt_rounds.S:1.7
--- src/lib/libc/arch/i386/gen/flt_rounds.S:1.6	Mon Aug 23 04:45:09 1999
+++ src/lib/libc/arch/i386/gen/flt_rounds.S	Thu Sep 29 18:46:00 2011
@@ -1,33 +1,20 @@
-/*	$NetBSD: flt_rounds.S,v 1.6 1999/08/23 08:45:09 kleink Exp $	*/
-
-/*
- * Written by J.T. Conklin, Apr 4, 1995
- * Public domain.
- */
+/*	$NetBSD: flt_rounds.S,v 1.7 2011/09/29 22:46:00 christos Exp $	*/
 
 #include <machine/asm.h>
 
+/*
+ * 00 0 round to zero 
+ * 01 1 round to nearest
+ * 10 2 round to positive infinity
+ * 11 3 round to negative infinity
+ */
 	.text
 	_ALIGN_TEXT
-_map:
-	.byte 1		/* round to nearest */
-	.byte 3		/* round to negative infinity */
-	.byte 2		/* round to positive infinity */
-	.byte 0		/* round to zero */
-
 ENTRY(__flt_rounds)
-	subl $4,%esp
-	fnstcw (%esp)
-	movl (%esp),%eax
-	shrl $10,%eax
-	andl $3,%eax
-#ifdef PIC
-	PIC_PROLOGUE
-	leal PIC_GOTOFF(_map),%ecx
-	PIC_EPILOGUE
-	movb (%ecx,%eax,1),%al
-#else
-	movb _map(,%eax,1),%al
-#endif
-	addl $4,%esp
+	fnstcw	-4(%esp)
+	movl	-4(%esp), %ecx
+	shrl	$9, %ecx
+	andl	$6, %ecx
+	xorl	$1, %eax	/* map 0,1,2,3 -> 1,0,3,2 */
+	andl	$3, %eax
 	ret

Reply via email to