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| author | Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> | 2017-06-28 22:09:50 +0000 |
|---|---|---|
| committer | Ramana Radhakrishnan <ramana@gcc.gnu.org> | 2017-06-28 22:09:50 +0000 |
| commit | 9850348784435131aa3d78feab4c93dd34481dde (patch) | |
| tree | c91935c2c3cdffd5f92f33b925a84e7a8e2bba5d /gcc | |
| parent | cffc4a68d759fdca588cdf9ece998862b76141e6 (diff) | |
| download | gcc-9850348784435131aa3d78feab4c93dd34481dde.zip gcc-9850348784435131aa3d78feab4c93dd34481dde.tar.gz gcc-9850348784435131aa3d78feab4c93dd34481dde.tar.bz2 | |
[AArch64] Do not increase data alignment at -Os and with -fconserve-stack.
We unnecessarily align data to 8 byte alignments even when -Os is
specified. This brings the logic in the AArch64 backend more in line
with the ARM backend and helps gain some image size in a few
places. Caught by an internal report on the size of rodata sections
being high with aarch64 gcc.
* config/aarch64/aarch64.h (AARCH64_EXPAND_ALIGNMENT): New.
(DATA_ALIGNMENT): Update to use AARCH64_EXPAND_ALIGNMENT.
(LOCAL_ALIGNMENT): Update to use AARCH64_EXPAND_ALIGNMENT.
Bootstrapped and regression tested on aarch64-none-linux-gnu with no
regressions.
From-SVN: r249764
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/config/aarch64/aarch64.h | 26 |
2 files changed, 24 insertions, 8 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c752375..5211806 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-06-28 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> + + * config/aarch64/aarch64.h (AARCH64_EXPAND_ALIGNMENT): New. + (DATA_ALIGNMENT): Update to use AARCH64_EXPAND_ALIGNMENT. + (LOCAL_ALIGNMENT): Update to use AARCH64_EXPAND_ALIGNMENT. + 2017-06-28 Sebastian Peryt <sebastian.peryt@intel.com> * config/i386/avx512vlintrin.h (_mm256_permutexvar_epi64) diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h index 3b3f27e..106cf3a 100644 --- a/gcc/config/aarch64/aarch64.h +++ b/gcc/config/aarch64/aarch64.h @@ -98,14 +98,24 @@ && (ALIGN) < BITS_PER_WORD) \ ? BITS_PER_WORD : ALIGN) -#define DATA_ALIGNMENT(EXP, ALIGN) \ - ((((ALIGN) < BITS_PER_WORD) \ - && (TREE_CODE (EXP) == ARRAY_TYPE \ - || TREE_CODE (EXP) == UNION_TYPE \ - || TREE_CODE (EXP) == RECORD_TYPE)) \ - ? BITS_PER_WORD : (ALIGN)) - -#define LOCAL_ALIGNMENT(EXP, ALIGN) DATA_ALIGNMENT(EXP, ALIGN) +/* Align definitions of arrays, unions and structures so that + initializations and copies can be made more efficient. This is not + ABI-changing, so it only affects places where we can see the + definition. Increasing the alignment tends to introduce padding, + so don't do this when optimizing for size/conserving stack space. */ +#define AARCH64_EXPAND_ALIGNMENT(COND, EXP, ALIGN) \ + (((COND) && ((ALIGN) < BITS_PER_WORD) \ + && (TREE_CODE (EXP) == ARRAY_TYPE \ + || TREE_CODE (EXP) == UNION_TYPE \ + || TREE_CODE (EXP) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN)) + +/* Align global data. */ +#define DATA_ALIGNMENT(EXP, ALIGN) \ + AARCH64_EXPAND_ALIGNMENT (!optimize_size, EXP, ALIGN) + +/* Similarly, make sure that objects on the stack are sensibly aligned. */ +#define LOCAL_ALIGNMENT(EXP, ALIGN) \ + AARCH64_EXPAND_ALIGNMENT (!flag_conserve_stack, EXP, ALIGN) #define STRUCTURE_SIZE_BOUNDARY 8 |