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| author | Andrew Pinski <quic_apinski@quicinc.com> | 2024-01-30 00:50:56 -0800 |
|---|---|---|
| committer | Andrew Pinski <quic_apinski@quicinc.com> | 2024-01-31 16:18:41 -0800 |
| commit | dbf847d2c8d1c910948ba34c9338939c67323273 (patch) | |
| tree | 5756ff7125cdf0c1e75732608d6b794a497e2164 /gcc/config | |
| parent | cc7aebff74d8967563fd9af5cb958dfcc8c111e8 (diff) | |
| download | gcc-dbf847d2c8d1c910948ba34c9338939c67323273.zip gcc-dbf847d2c8d1c910948ba34c9338939c67323273.tar.gz gcc-dbf847d2c8d1c910948ba34c9338939c67323273.tar.bz2 | |
aarch64: -mstrict-align vs __arm_data512_t [PR113657]
After r14-1187-gd6b756447cd58b, simplify_gen_subreg can return
NULL for "unaligned" memory subreg. Since V8DI has an alignment of 8 bytes,
using TImode causes simplify_gen_subreg to return NULL.
This fixes the issue by using DImode instead for the loop. And then we will have
later on the STP/LDP pass combine it back into STP/LDP if needed.
Since strict align is less important (usually used for firmware and early boot only),
not doing LDP/STP here is ok.
Built and tested for aarch64-linux-gnu with no regressions.
PR target/113657
gcc/ChangeLog:
* config/aarch64/aarch64-simd.md (split for movv8di):
For strict aligned mode, use DImode instead of TImode.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/acle/ls64_strict_align.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
Diffstat (limited to 'gcc/config')
| -rw-r--r-- | gcc/config/aarch64/aarch64-simd.md | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md index f036f6c..f8bb973 100644 --- a/gcc/config/aarch64/aarch64-simd.md +++ b/gcc/config/aarch64/aarch64-simd.md @@ -8221,14 +8221,17 @@ || (memory_operand (operands[0], V8DImode) && register_operand (operands[1], V8DImode))) { + /* V8DI only guarantees 8-byte alignment, whereas TImode requires 16. */ + auto mode = STRICT_ALIGNMENT ? DImode : TImode; + int increment = GET_MODE_SIZE (mode); std::pair<rtx, rtx> last_pair = {}; - for (int offset = 0; offset < 64; offset += 16) + for (int offset = 0; offset < 64; offset += increment) { std::pair<rtx, rtx> pair = { - simplify_gen_subreg (TImode, operands[0], V8DImode, offset), - simplify_gen_subreg (TImode, operands[1], V8DImode, offset) + simplify_gen_subreg (mode, operands[0], V8DImode, offset), + simplify_gen_subreg (mode, operands[1], V8DImode, offset) }; - if (register_operand (pair.first, TImode) + if (register_operand (pair.first, mode) && reg_overlap_mentioned_p (pair.first, pair.second)) last_pair = pair; else |