https://gcc.gnu.org/g:0ed93581f1883cf09b1639fb21f3d9fddd46aa32
commit 0ed93581f1883cf09b1639fb21f3d9fddd46aa32 Author: Michael Meissner <[email protected]> Date: Thu Jun 25 05:08:32 2026 -0400 PR target/117251: Improve vector fusion #7 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 #2 of 45 to generate the 'XXEVAL' instruction on power10 and power11 instead of using the Altivec 'VANDC' instruction feeding into 'VAND'. 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. For vectors such as: vector int a, b, c, d; This patch will generate a call to xxeval if any of the registers are allocated to traditional floating point registers: Code: Old: New: ===== ==== ==== a = ~ ((~ (c | d)) & b); vnor t,c,d xxeval a,b,c,d,247 vnand a,t,b a = ~ ((c | d) & b); vor t,c,d xxeval a,b,c,d,248 vnand a,t,b a = ~ ((c ^ d) & b); vxor t,c,d xxeval a,b,c,d,249 vnand a,t,b a = ~ ((c & ~ d) & b); vandc t,c,d xxeval a,b,c,d,253 vnand a,t,b a = ~ ((c & d) & b); vand t,c,d xxeval a,b,c,d,254 vnand a,t,b 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? 2026-06-25 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/vector fusion if XXEVAL is supported. Diff: --- gcc/config/rs6000/fusion.md | 55 +++++++++++++++++++++++------------------- gcc/config/rs6000/genfusion.pl | 5 ++++ 2 files changed, 35 insertions(+), 25 deletions(-) diff --git a/gcc/config/rs6000/fusion.md b/gcc/config/rs6000/fusion.md index 95d7a5ba0c11..d433629c3a0c 100644 --- a/gcc/config/rs6000/fusion.md +++ b/gcc/config/rs6000/fusion.md @@ -2336,16 +2336,17 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vand -> vnand (define_insn "*fuse_vand_vnand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (not: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"))) - (not:VM (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 (not: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"))) + (not:VM (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\;vnand %3,%3,%2 vand %3,%1,%0\;vnand %3,%3,%2 vand %3,%1,%0\;vnand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,254 vand %4,%1,%0\;vnand %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") @@ -2356,16 +2357,17 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vandc -> vnand (define_insn "*fuse_vandc_vnand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (not:VM (and:VM (not:VM (match_operand:VM 0 "altivec_register_operand" "v,v,v,v")) - (match_operand:VM 1 "altivec_register_operand" "v,v,v,v"))) - (not:VM (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 (not:VM (and:VM (not: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"))) + (not:VM (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)" "@ vandc %3,%1,%0\;vnand %3,%3,%2 vandc %3,%1,%0\;vnand %3,%3,%2 vandc %3,%1,%0\;vnand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,253 vandc %4,%1,%0\;vnand %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") @@ -2418,16 +2420,17 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vnor -> vnand (define_insn "*fuse_vnor_vnand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (not:VM (and:VM (not:VM (match_operand:VM 0 "altivec_register_operand" "v,v,v,v")) - (not:VM (match_operand:VM 1 "altivec_register_operand" "v,v,v,v")))) - (not:VM (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 (not:VM (and:VM (not:VM (match_operand:VM 0 "vector_fusion_operand" "v,v,v,wa,v")) + (not:VM (match_operand:VM 1 "vector_fusion_operand" "v,v,v,wa,v")))) + (not:VM (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)" "@ vnor %3,%1,%0\;vnand %3,%3,%2 vnor %3,%1,%0\;vnand %3,%3,%2 vnor %3,%1,%0\;vnand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,247 vnor %4,%1,%0\;vnand %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") @@ -2438,16 +2441,17 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vor -> vnand (define_insn "*fuse_vor_vnand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (not:VM (ior:VM (match_operand:VM 0 "altivec_register_operand" "v,v,v,v") - (match_operand:VM 1 "altivec_register_operand" "v,v,v,v"))) - (not:VM (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 (not:VM (ior: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"))) + (not:VM (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)" "@ vor %3,%1,%0\;vnand %3,%3,%2 vor %3,%1,%0\;vnand %3,%3,%2 vor %3,%1,%0\;vnand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,248 vor %4,%1,%0\;vnand %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") @@ -2479,16 +2483,17 @@ ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vxor -> vnand (define_insn "*fuse_vxor_vnand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (ior:VM (not:VM (xor:VM (match_operand:VM 0 "altivec_register_operand" "v,v,v,v") - (match_operand:VM 1 "altivec_register_operand" "v,v,v,v"))) - (not:VM (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 (not:VM (xor: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"))) + (not:VM (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)" "@ vxor %3,%1,%0\;vnand %3,%3,%2 vxor %3,%1,%0\;vnand %3,%3,%2 vxor %3,%1,%0\;vnand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,249 vxor %4,%1,%0\;vnand %3,%4,%2" [(set_attr "type" "fused_vector") (set_attr "cost" "6") diff --git a/gcc/config/rs6000/genfusion.pl b/gcc/config/rs6000/genfusion.pl index 62d19c0de031..3fc14e6d5eb7 100755 --- a/gcc/config/rs6000/genfusion.pl +++ b/gcc/config/rs6000/genfusion.pl @@ -254,6 +254,11 @@ sub gen_logical_addsubf "vnand_vnand" => 241, "vorc_vnand" => 244, "veqv_vnand" => 246, + "vnor_vnand" => 247, + "vor_vnand" => 248, + "vxor_vnand" => 249, + "vandc_vnand" => 253, + "vand_vnand" => 254, ); KIND: foreach $kind ('scalar','vector') {
