diff options
| author | Andre McCurdy <armccurdy@gmail.com> | 2019-09-13 11:44:31 -0700 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2020-01-16 15:44:26 -0500 |
| commit | 91e662d1d941215eb024787db5e910dbfb5b169f (patch) | |
| tree | d3b2506ee656488fd55cdae9923373c2e354a8dd | |
| parent | 0ff18be20833928064f6eff88e590cea9625f602 (diff) | |
| download | musl-91e662d1d941215eb024787db5e910dbfb5b169f.tar.gz | |
add thumb2 support to arm assembler memcpy
For Thumb2 compatibility, replace two instances of a single
instruction "orr with a variable shift" with the two instruction
equivalent. Neither of the replacements are in a performance critical
loop.
| -rw-r--r-- | src/string/arm/memcpy.c | 2 | ||||
| -rw-r--r-- | src/string/arm/memcpy_le.S | 13 |
2 files changed, 9 insertions, 6 deletions
diff --git a/src/string/arm/memcpy.c b/src/string/arm/memcpy.c index f703c9bd..041614f4 100644 --- a/src/string/arm/memcpy.c +++ b/src/string/arm/memcpy.c @@ -1,3 +1,3 @@ -#if __ARMEB__ || __thumb__ +#if __ARMEB__ #include "../memcpy.c" #endif diff --git a/src/string/arm/memcpy_le.S b/src/string/arm/memcpy_le.S index 9cfbcb2a..7b35d305 100644 --- a/src/string/arm/memcpy_le.S +++ b/src/string/arm/memcpy_le.S @@ -1,4 +1,4 @@ -#if !__ARMEB__ && !__thumb__ +#if !__ARMEB__ /* * Copyright (C) 2008 The Android Open Source Project @@ -40,8 +40,9 @@ * This file has been modified from the original for use in musl libc. * The main changes are: addition of .type memcpy,%function to make the * code safely callable from thumb mode, adjusting the return - * instructions to be compatible with pre-thumb ARM cpus, and removal - * of prefetch code that is not compatible with older cpus. + * instructions to be compatible with pre-thumb ARM cpus, removal of + * prefetch code that is not compatible with older cpus and support for + * building as thumb 2. */ .syntax unified @@ -241,7 +242,8 @@ non_congruent: beq 2f ldr r5, [r1], #4 sub r2, r2, #4 - orr r4, r3, r5, lsl lr + mov r4, r5, lsl lr + orr r4, r4, r3 mov r3, r5, lsr r12 str r4, [r0], #4 cmp r2, #4 @@ -348,7 +350,8 @@ less_than_thirtytwo: 1: ldr r5, [r1], #4 sub r2, r2, #4 - orr r4, r3, r5, lsl lr + mov r4, r5, lsl lr + orr r4, r4, r3 mov r3, r5, lsr r12 str r4, [r0], #4 cmp r2, #4 |