diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/riscv/riscv.cc | 57 |
1 files changed, 37 insertions, 20 deletions
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc index 0f62b295b96..24d1ead3902 100644 --- a/gcc/config/riscv/riscv.cc +++ b/gcc/config/riscv/riscv.cc @@ -8874,26 +8874,43 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn *curr) extract_base_offset_in_addr (SET_DEST (prev_set), &base_prev, &offset_prev); extract_base_offset_in_addr (SET_DEST (curr_set), &base_curr, &offset_curr); - /* The two stores must be contained within opposite halves of the same - 16 byte aligned block of memory. We know that the stack pointer and - the frame pointer have suitable alignment. So we just need to check - the offsets of the two stores for suitable alignment. - - Originally the thought was to check MEM_ALIGN, but that was reporting - incorrect alignments, even for SP/FP accesses, so we gave up on that - approach. */ - if (base_prev != NULL_RTX - && base_curr != NULL_RTX - && REG_P (base_prev) - && REG_P (base_curr) - && REGNO (base_prev) == REGNO (base_curr) - && (REGNO (base_prev) == STACK_POINTER_REGNUM - || REGNO (base_prev) == HARD_FRAME_POINTER_REGNUM) - && ((INTVAL (offset_prev) == INTVAL (offset_curr) + 8 - && (INTVAL (offset_prev) % 16) == 0) - || ((INTVAL (offset_curr) == INTVAL (offset_prev) + 8) - && (INTVAL (offset_curr) % 16) == 0))) - return true; + /* Fail if we did not find both bases. */ + if (base_prev == NULL_RTX || base_curr == NULL_RTX) + return false; + + /* Fail if either base is not a register. */ + if (!REG_P (base_prev) || !REG_P (base_curr)) + return false; + + /* Fail if the bases are not the same register. */ + if (REGNO (base_prev) != REGNO (base_curr)) + return false; + + /* Originally the thought was to check MEM_ALIGN, but that was + reporting incorrect alignments, even for SP/FP accesses, so we + gave up on that approach. Instead just check for stack/hfp + which we know are aligned. */ + if (REGNO (base_prev) != STACK_POINTER_REGNUM + && REGNO (base_prev) != HARD_FRAME_POINTER_REGNUM) + return false; + + /* The two stores must be contained within opposite halves of the + same 16 byte aligned block of memory. We know that the stack + pointer and the frame pointer have suitable alignment. So we + just need to check the offsets of the two stores for suitable + alignment. */ + /* Get the smaller offset into OFFSET_PREV. */ + if (INTVAL (offset_prev) > INTVAL (offset_curr)) + std::swap (offset_prev, offset_curr); + + /* If the smaller offset (OFFSET_PREV) is not 16 byte aligned, + then fail. */ + if ((INTVAL (offset_prev) % 16) != 0) + return false; + + /* The higher offset must be 8 bytes more than the lower + offset. */ + return (INTVAL (offset_prev) + 8 == INTVAL (offset_curr)); } } |