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_apin...@quicinc.com> --- gcc/config/aarch64/aarch64-simd.md | 11 +++++++---- .../gcc.target/aarch64/acle/ls64_strict_align.c | 7 +++++++ 2 files changed, 14 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/gcc.target/aarch64/acle/ls64_strict_align.c diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md index 7a6b4430112..4023b918882 100644 --- a/gcc/config/aarch64/aarch64-simd.md +++ b/gcc/config/aarch64/aarch64-simd.md @@ -8221,14 +8221,17 @@ (define_split || (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 diff --git a/gcc/testsuite/gcc.target/aarch64/acle/ls64_strict_align.c b/gcc/testsuite/gcc.target/aarch64/acle/ls64_strict_align.c new file mode 100644 index 00000000000..bf49ac76f78 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/acle/ls64_strict_align.c @@ -0,0 +1,7 @@ +/* { dg-do compile } */ +/* { dg-options "-mstrict-align" } */ +/* PR target/113657 */ + +#pragma GCC target "+ls64" +#pragma GCC aarch64 "arm_acle.h" +__arm_data512_t foo(__arm_data512_t* ptr) { return *ptr; } -- 2.39.3