Make armv6t2 strlen work in ARM mode too.

diff --git a/ports/ChangeLog.arm b/ports/ChangeLog.arm
index 2a95834..1806b08 100644 (file)
--- a/ports/ChangeLog.arm
+++ b/ports/ChangeLog.arm
@@ -1,3 +1,8 @@
+2013-08-30  Roland McGrath  <roland@hack.frob.com>
+
+       * sysdeps/arm/armv6t2/strlen.S: Include <arm-features.h> first thing.
+       [NO_THUMB]: Adapt code for ARM mode.
+
 2013-08-30  Will Newton  <will.newton@linaro.org>
 
        [BZ #15909]

diff --git a/ports/sysdeps/arm/armv6t2/strlen.S b/ports/sysdeps/arm/armv6t2/strlen.S
index a52e2e7..4652c20 100644 (file)
--- a/ports/sysdeps/arm/armv6t2/strlen.S
+++ b/ports/sysdeps/arm/armv6t2/strlen.S
@@ -21,6 +21,7 @@
 
  */
 
+#include <arm-features.h>               /* This might #define NO_THUMB.  */
 #include <sysdep.h>
 
 #ifdef __ARMEB__
@@ -31,9 +32,24 @@
 #define S2HI           lsl
 #endif
 
-       /* This code requires Thumb.  */
+#ifndef NO_THUMB
+/* This code is best on Thumb.  */
        .thumb
-       .syntax unified
+#else
+/* Using bne.w explicitly is desirable in Thumb mode because it helps
+   align the following label without a nop.  In ARM mode there is no
+   such difference.  */
+.macro bne.w label
+       bne \label
+.endm
+
+/* This clobbers the condition codes, which the real Thumb cbnz instruction
+   does not do.  But it doesn't matter for any of the uses here.  */
+.macro cbnz reg, label
+       cmp \reg, #0
+       bne \label
+.endm
+#endif
 
 /* Parameters and result.  */
 #define srcin          r0
@@ -130,9 +146,16 @@ ENTRY(strlen)
        tst     tmp1, #4
        pld     [src, #64]
        S2HI    tmp2, const_m1, tmp2
+#ifdef NO_THUMB
+       mvn     tmp1, tmp2
+       orr     data1a, data1a, tmp1
+       itt     ne
+       orrne   data1b, data1b, tmp1
+#else
        orn     data1a, data1a, tmp2
        itt     ne
        ornne   data1b, data1b, tmp2
+#endif
        movne   data1a, const_m1
        mov     const_0, #0
        b       .Lstart_realigned