https://gcc.gnu.org/g:58896353b55ca7c4ff7e0029cd4c65bc57519726
commit 58896353b55ca7c4ff7e0029cd4c65bc57519726 Author: Michael Meissner <[email protected]> Date: Mon Sep 8 15:19:20 2025 -0400 PR target/117251: Improve vector and to vector or fusion See the following post for a complete explanation of what the patches for PR target/117251: * https://gcc.gnu.org/pipermail/gcc-patches/2025-June/686474.html This is patch #12 of 45 to generate the 'XXEVAL' instruction on power10 and power11 instead of using the Altivec 'VAND' instruction feeding into 'VOR'. The 'XXEVAL' instruction can use all 64 vector registers, instead of the 32 registers that traditional Altivec vector instructions use. By allowing all of the vector registers to be used, it reduces the amount of spilling that a large benchmark generated. Currently the following code: vector int a, b, c, d; a = (c & d) | b; Generates: vand t,c,d vor a,t,b Now in addition with this patch, if the arguments or result is allocated to a traditional FPR register, the GCC compiler will now generate the following code instead of adding vector move instructions: xxeval a,b,c,31 Since fusion using 2 Altivec instructions is slightly faster than using the 'XXEVAL' instruction we prefer to generate the Altivec instructions if we can. In addition, because 'XXEVAL' is a prefixed instruction, it possibly might generate an extra NOP instruction to align the 'XXEVAL' instruction. I have tested these patches on both big endian and little endian PowerPC servers, with no regressions. Can I check these patchs into the trunk? 2025-09-08 Michael Meissner <[email protected]> gcc/ PR target/117251 * config/rs6000/fusion.md: Regenerate. * config/rs6000/genfusion.pl (gen_logical_addsubf): Add support to generate vector and => or fusion if XXEVAL is supported. Diff: --- gcc/config/rs6000/fusion.md | 15 +++++++++------ gcc/config/rs6000/genfusion.pl | 1 + 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/gcc/config/rs6000/fusion.md b/gcc/config/rs6000/fusion.md index 789a4d592419..fccea39d0aae 100644 --- a/gcc/config/rs6000/fusion.md +++ b/gcc/config/rs6000/fusion.md @@ -2621,20 +2621,23 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vand -> vor (define_insn "*fuse_vand_vor" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (and:VM (match_operand:VM 0 "altivec_register_operand" "v,v,v,v") - (match_operand:VM 1 "altivec_register_operand" "v,v,v,v")) - (match_operand:VM 2 "altivec_register_operand" "v,v,v,v"))) - (clobber (match_scratch:VM 4 "=X,X,X,&v"))] + [(set (match_operand:VM 3 "vector_fusion_operand" "=&0,&1,&v,wa,v") + (ior:VM (and:VM (match_operand:VM 0 "vector_fusion_operand" "v,v,v,wa,v") + (match_operand:VM 1 "vector_fusion_operand" "v,v,v,wa,v")) + (match_operand:VM 2 "vector_fusion_operand" "v,v,v,wa,v"))) + (clobber (match_scratch:VM 4 "=X,X,X,X,&v"))] "(TARGET_P10_FUSION)" "@ vand %3,%1,%0\;vor %3,%3,%2 vand %3,%1,%0\;vor %3,%3,%2 vand %3,%1,%0\;vor %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,31 vand %4,%1,%0\;vor %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") - (set_attr "length" "8")]) + (set_attr "length" "8") + (set_attr "prefixed" "*,*,*,yes,*") + (set_attr "isa" "*,*,*,xxeval,*")]) ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vandc -> vor diff --git a/gcc/config/rs6000/genfusion.pl b/gcc/config/rs6000/genfusion.pl index e6d44d430b3a..ab714b10f622 100755 --- a/gcc/config/rs6000/genfusion.pl +++ b/gcc/config/rs6000/genfusion.pl @@ -226,6 +226,7 @@ sub gen_logical_addsubf "vnand_vand" => 14, "vnand_vnor" => 16, "vand_vxor" => 30, + "vand_vor" => 31, ); KIND: foreach $kind ('scalar','vector') {
