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- commit b050f87d13b5dc7ed82feb9a90f4529de58bdf25
- Author: Felix Fietkau <nbd@openwrt.org>
- Date: Wed Feb 19 19:20:10 2014 +0000
-
- gcc: prevent the use of LDRD/STRD on ARMv5TE
-
- These instructions are for 64-bit load/store. On ARMv5TE, the CPU
- requires addresses to be aligned to 64-bit. When misaligned, behavior is
- undefined (effectively either loads the same word twice on LDRD, or
- corrupts surrounding memory on STRD).
-
- On ARMv6 and newer, unaligned access is safe.
-
- Removing these instructions for ARMv5TE is necessary, because GCC
- ignores alignment information in pointers and does unsafe optimizations
- that have shown up as bugs in various places.
-
- Signed-off-by: Felix Fietkau <nbd@openwrt.org>
-
- SVN-Revision: 39638
-
- --- a/gcc/config/arm/arm.h
- +++ b/gcc/config/arm/arm.h
- @@ -150,7 +150,7 @@ extern tree arm_fp16_type_node;
- /* Thumb-1 only. */
- #define TARGET_THUMB1_ONLY (TARGET_THUMB1 && !arm_arch_notm)
-
- -#define TARGET_LDRD (arm_arch5e && ARM_DOUBLEWORD_ALIGN \
- +#define TARGET_LDRD (arm_arch6 && ARM_DOUBLEWORD_ALIGN \
- && !TARGET_THUMB1)
-
- #define TARGET_CRC32 (arm_arch_crc)
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