]>
git.ipfire.org Git - thirdparty/gcc.git/commit
LoongArch: Modify the address calculation logic for obtaining array element values through fp.
Modify address calculation logic from (((a x C) + fp) + offset) to ((fp + offset) + a x C).
Thereby modifying the register dependencies and optimizing the code.
The value of C is 2 4 or 8.
The following is the assembly code before and after a loop modification in spec2006 401.bzip:
old | new
735 .L71: | 735 .L71:
736 slli.d $r12,$r15,2 | 736 slli.d $r12,$r15,2
737 ldx.w $r13,$r22,$r12 | 737 ldx.w $r13,$r22,$r12
738 addi.d $r15,$r15,-1 | 738 addi.d $r15,$r15,-1
739 slli.w $r16,$r15,0 | 739 slli.w $r16,$r15,0
740 addi.w $r13,$r13,-1 | 740 addi.w $r13,$r13,-1
741 slti $r14,$r13,0 | 741 slti $r14,$r13,0
742 add.w $r12,$r26,$r13 | 742 add.w $r12,$r26,$r13
743 maskeqz $r12,$r12,$r14 | 743 maskeqz $r12,$r12,$r14
744 masknez $r14,$r13,$r14 | 744 masknez $r14,$r13,$r14
745 or $r12,$r12,$r14 | 745 or $r12,$r12,$r14
746 ldx.bu $r14,$r30,$r12 | 746 ldx.bu $r14,$r30,$r12
747 lu12i.w $r13,4096>>12 | 747 alsl.d $r14,$r14,$r18,2
748 ori $r13,$r13,432 | 748 ldptr.w $r13,$r14,0
749 add.d $r13,$r13,$r3 | 749 addi.w $r17,$r13,-1
750 alsl.d $r14,$r14,$r13,2 | 750 stptr.w $r17,$r14,0
751 ldptr.w $r13,$r14,-1968 | 751 slli.d $r13,$r13,2
752 addi.w $r17,$r13,-1 | 752 stx.w $r12,$r22,$r13
753 st.w $r17,$r14,-1968 | 753 ldptr.w $r12,$r19,0
754 slli.d $r13,$r13,2 | 754 blt $r12,$r16,.L71
755 stx.w $r12,$r22,$r13 | 755 .align 4
756 ldptr.w $r12,$r18,-2048 | 756
757 blt $r12,$r16,.L71 | 757
758 .align 4 | 758
This patch is ported from riscv's commit r14-3111.
gcc/ChangeLog:
* config/loongarch/loongarch.cc (mem_shadd_or_shadd_rtx_p): New function.
(loongarch_legitimize_address): Add logical transformation code.