This patch enables the overlap-by-pieces feature of the by-pieces infrastructure for inlining builtins in case the target has set riscv_slow_unaligned_access_p to false.
To demonstrate the effect for targets with fast unaligned access, the following code sequences are generated for a 15-byte memset-zero. Without overlap_op_by_pieces we get: 8e: 00053023 sd zero,0(a0) 92: 00052423 sw zero,8(a0) 96: 00051623 sh zero,12(a0) 9a: 00050723 sb zero,14(a0) With overlap_op_by_pieces we get: 7e: 00053023 sd zero,0(a0) 82: 000533a3 sd zero,7(a0) gcc/ChangeLog: * config/riscv/riscv.c (riscv_overlap_op_by_pieces): New function. (TARGET_OVERLAP_OP_BY_PIECES_P): Connect to riscv_overlap_op_by_pieces. Signed-off-by: Christoph Muellner <cmuell...@gcc.gnu.org> --- gcc/config/riscv/riscv.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c index 576960bb37c..98c76ba657a 100644 --- a/gcc/config/riscv/riscv.c +++ b/gcc/config/riscv/riscv.c @@ -5201,6 +5201,14 @@ riscv_slow_unaligned_access (machine_mode, unsigned int) return riscv_slow_unaligned_access_p; } +/* Implement TARGET_OVERLAP_OP_BY_PIECES_P. */ + +static bool +riscv_overlap_op_by_pieces (void) +{ + return !riscv_slow_unaligned_access_p; +} + /* Implement TARGET_CAN_CHANGE_MODE_CLASS. */ static bool @@ -5525,6 +5533,9 @@ riscv_asan_shadow_offset (void) #undef TARGET_SLOW_UNALIGNED_ACCESS #define TARGET_SLOW_UNALIGNED_ACCESS riscv_slow_unaligned_access +#undef TARGET_OVERLAP_OP_BY_PIECES_P +#define TARGET_OVERLAP_OP_BY_PIECES_P riscv_overlap_op_by_pieces + #undef TARGET_SECONDARY_MEMORY_NEEDED #define TARGET_SECONDARY_MEMORY_NEEDED riscv_secondary_memory_needed -- 2.31.1