Module Name: src
Committed By: jakllsch
Date: Wed Sep 9 14:49:27 UTC 2020
Modified Files:
src/common/lib/libc/arch/aarch64/string: strlen.S
Log Message:
Re-do previous aarch64eb strlen fix more simply and correctly.
To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/common/lib/libc/arch/aarch64/string/strlen.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/common/lib/libc/arch/aarch64/string/strlen.S
diff -u src/common/lib/libc/arch/aarch64/string/strlen.S:1.4 src/common/lib/libc/arch/aarch64/string/strlen.S:1.5
--- src/common/lib/libc/arch/aarch64/string/strlen.S:1.4 Sat Sep 5 20:24:43 2020
+++ src/common/lib/libc/arch/aarch64/string/strlen.S Wed Sep 9 14:49:27 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: strlen.S,v 1.4 2020/09/05 20:24:43 jakllsch Exp $ */
+/* $NetBSD: strlen.S,v 1.5 2020/09/09 14:49:27 jakllsch Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
#include <machine/asm.h>
-RCSID("$NetBSD: strlen.S,v 1.4 2020/09/05 20:24:43 jakllsch Exp $")
+RCSID("$NetBSD: strlen.S,v 1.5 2020/09/09 14:49:27 jakllsch Exp $")
#ifdef STRNLEN
#define FUNCNAME strnlen
@@ -66,12 +66,11 @@ ENTRY(FUNCNAME)
*/
add x4, x4, x0 /* make dword aligned */
ldr x7, [x4], #8 /* load dword */
- lsl x3, x3, #3 /* convert bytes to bits */
#ifdef __AARCH64EB__
- lsr x5, x11, x3 /* make mask for BE */
-#else
- lsl x5, x11, x3 /* make mask for LE */
+ rev x7, x7 /* convert to LE */
#endif
+ lsl x3, x3, #3 /* convert bytes to bits */
+ lsl x5, x11, x3 /* make mask for LE */
eor x5, x5, x11 /* invert mask */
orr x7, x7, x5 /* prevent NULs */
b .Lstrlen_dword_loop_noload
@@ -82,6 +81,9 @@ ENTRY(FUNCNAME)
b.hs .Lstrlen_done
#endif
ldr x7, [x4], #8 /* load dword */
+#ifdef __AARCH64EB__
+ rev x7, x7 /* convert to LE */
+#endif
.Lstrlen_dword_loop_noload:
/*
* Use the formula (X - 1) & ~(X | 0x7f) to find NUL bytes.
@@ -96,14 +98,6 @@ ENTRY(FUNCNAME)
/*
* We know there is a NUL in this dword. Use clz to find it.
*/
-#ifdef __AARCH64EB__
- /* avoid BE problem due to carry propagation if last non-NUL is \x01 */
- ldr x7, [x4, #-8] /* reload dword */
- rev x7, x7 /* byte swap */
- sub x6, x7, x11 /* a = X - 1 */
- orr x7, x7, #MASK8_0x7f /* b = X | 0x7f */
- bic x6, x6, x7 /* a & ~b */
-#endif
rev x6, x6 /* convert to BE */
clz x6, x6 /* find null byte */
add x0, x0, x6, lsr #3 /* add offset to the length */
