Module Name: src
Committed By: christos
Date: Thu Sep 29 22:45:21 UTC 2011
Modified Files:
src/lib/libc/arch/x86_64/gen: flt_rounds.S
Log Message:
add a simpler version.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/lib/libc/arch/x86_64/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/x86_64/gen/flt_rounds.S
diff -u src/lib/libc/arch/x86_64/gen/flt_rounds.S:1.3 src/lib/libc/arch/x86_64/gen/flt_rounds.S:1.4
--- src/lib/libc/arch/x86_64/gen/flt_rounds.S:1.3 Wed Sep 28 11:11:42 2011
+++ src/lib/libc/arch/x86_64/gen/flt_rounds.S Thu Sep 29 18:45:20 2011
@@ -1,29 +1,20 @@
-/* $NetBSD: flt_rounds.S,v 1.3 2011/09/28 15:11:42 christos Exp $ */
-
-/*
- * Written by J.T. Conklin, Apr 4, 1995
- * Public domain.
- */
+/* $NetBSD: flt_rounds.S,v 1.4 2011/09/29 22:45:20 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)
- fnstcw -4(%rsp)
- movl -4(%rsp),%eax
- shrl $10,%eax
- andl $3,%eax
-#ifdef PIC
- leaq _map(%rip),%rcx
- movb (%rcx,%rax,1),%al
-#else
- movb _map(,%rax,1),%al
-#endif
+ fnstcw -4(%rsp)
+ movl -4(%rsp), %ecx
+ shrl $9, %ecx
+ andl $6, %ecx
+ xorl $1, %eax /* map 0,1,2,3 -> 1,0,3,2 */
+ andl $3, %eax
ret
