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 #1 of 45 to generate the 'XXEVAL' instruction on power10 and power11 instead of using the Altivec 'VAND' 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. Currently the following code: vector int a, b, c, d; a = (c & d) & b; Generates: vand t,c,d vand 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,1 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? 2025-06-11 Michael Meissner <meiss...@linux.ibm.com> gcc/ PR target/117251 * config/rs6000/fusion.md: Regenerate. * config/rs6000/genfusion.pl (gen_logical_addsubf): Add support to generate vector/vector and/and fusion if XXEVAL is supported. * config/rs6000/predicates.md (vector_fusion_operand): New predicate. * config/rs6000/rs6000.h (TARGET_XXEVAL): New macro. * config/rs6000/rs6000.md (isa attribute): Add xxeval. (enabled attribute): Add support for XXEVAL support. --- gcc/config/rs6000/fusion.md | 15 +++++---- gcc/config/rs6000/genfusion.pl | 58 ++++++++++++++++++++++++++++++--- gcc/config/rs6000/predicates.md | 12 +++++++ gcc/config/rs6000/rs6000.h | 4 +++ gcc/config/rs6000/rs6000.md | 7 +++- 5 files changed, 85 insertions(+), 11 deletions(-) diff --git a/gcc/config/rs6000/fusion.md b/gcc/config/rs6000/fusion.md index 621b346f9eb..d24837d68d8 100644 --- a/gcc/config/rs6000/fusion.md +++ b/gcc/config/rs6000/fusion.md @@ -1871,20 +1871,23 @@ (define_insn "*fuse_or_rsubf" ;; logical-logical fusion pattern generated by gen_logical_addsubf ;; vector vand -> vand (define_insn "*fuse_vand_vand" - [(set (match_operand:VM 3 "altivec_register_operand" "=&0,&1,&v,v") - (and: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") + (and: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\;vand %3,%3,%2 vand %3,%1,%0\;vand %3,%3,%2 vand %3,%1,%0\;vand %3,%3,%2 + xxeval %x3,%x2,%x1,%x0,1 vand %4,%1,%0\;vand %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 -> vand diff --git a/gcc/config/rs6000/genfusion.pl b/gcc/config/rs6000/genfusion.pl index e5d3b1ee449..351a4d914a4 100755 --- a/gcc/config/rs6000/genfusion.pl +++ b/gcc/config/rs6000/genfusion.pl @@ -211,25 +211,33 @@ sub gen_logical_addsubf $inner_comp, $inner_inv, $inner_rtl, $inner_op, $both_commute, $c4, $bc, $inner_arg0, $inner_arg1, $inner_exp, $outer_arg2, $outer_exp, $ftype, $insn, $is_subf, $is_rsubf, $outer_32, $outer_42,$outer_name, - $fuse_type); - KIND: foreach $kind ('scalar','vector') { + $fuse_type, $xxeval, $c5, $vect_pred, $vect_inner_arg0, $vect_inner_arg1, + $vect_inner_exp, $vect_outer_arg2, $vect_outer_exp); + + my %xxeval_fusions = ( + "vand_vand" => 1, + ); + + KIND: foreach $kind ('scalar','vector') { @outer_ops = @logicals; if ( $kind eq 'vector' ) { $vchr = "v"; $mode = "VM"; $pred = "altivec_register_operand"; + $vect_pred = "vector_fusion_operand"; $constraint = "v"; $fuse_type = "fused_vector"; } else { $vchr = ""; $mode = "GPR"; - $pred = "gpc_reg_operand"; + $vect_pred = $pred = "gpc_reg_operand"; $constraint = "r"; $fuse_type = "fused_arith_logical"; push (@outer_ops, @addsub); push (@outer_ops, ( "rsubf" )); } $c4 = "${constraint},${constraint},${constraint},${constraint}"; + $c5 = "${constraint},${constraint},${constraint},wa,${constraint}"; OUTER: foreach $outer ( @outer_ops ) { $outer_name = "${vchr}${outer}"; $is_subf = ( $outer eq "subf" ); @@ -263,23 +271,33 @@ sub gen_logical_addsubf $bc = ""; if ( $both_commute ) { $bc = "%"; } $inner_arg0 = "(match_operand:${mode} 0 \"${pred}\" \"${c4}\")"; $inner_arg1 = "(match_operand:${mode} 1 \"${pred}\" \"${bc}${c4}\")"; + $vect_inner_arg0 = "(match_operand:${mode} 0 \"${vect_pred}\" \"${c5}\")"; + $vect_inner_arg1 = "(match_operand:${mode} 1 \"${vect_pred}\" \"${bc}${c5}\")"; if ( ($inner_comp & 1) == 1 ) { $inner_arg0 = "(not:${mode} $inner_arg0)"; + $vect_inner_arg0 = "(not:${mode} $vect_inner_arg0)"; } if ( ($inner_comp & 2) == 2 ) { $inner_arg1 = "(not:${mode} $inner_arg1)"; + $vect_inner_arg1 = "(not:${mode} $vect_inner_arg1)"; } $inner_exp = "(${inner_rtl}:${mode} ${inner_arg0} ${inner_arg1})"; + $vect_inner_exp = "(${inner_rtl}:${mode} ${vect_inner_arg0} + ${vect_inner_arg1})"; if ( $inner_inv == 1 ) { $inner_exp = "(not:${mode} $inner_exp)"; + $vect_inner_exp = "(not:${mode} $vect_inner_exp)"; } $outer_arg2 = "(match_operand:${mode} 2 \"${pred}\" \"${c4}\")"; + $vect_outer_arg2 = "(match_operand:${mode} 2 \"${vect_pred}\" \"${c5}\")"; if ( ($outer_comp & 1) == 1 ) { $outer_arg2 = "(not:${mode} $outer_arg2)"; + $vect_outer_arg2 = "(not:${mode} $vect_outer_arg2)"; } if ( ($outer_comp & 2) == 2 ) { $inner_exp = "(not:${mode} $inner_exp)"; + $vect_inner_exp = "(not:${mode} $vect_inner_exp)"; } if ( $is_subf ) { $outer_32 = "%2,%3"; @@ -291,15 +309,23 @@ sub gen_logical_addsubf if ( $is_rsubf == 1 ) { $outer_exp = "(${outer_rtl}:${mode} ${outer_arg2} ${inner_exp})"; + $vect_outer_exp = "(${outer_rtl}:${mode} ${vect_outer_arg2} + ${vect_inner_exp})"; } else { $outer_exp = "(${outer_rtl}:${mode} ${inner_exp} ${outer_arg2})"; + $vect_outer_exp = "(${outer_rtl}:${mode} ${vect_inner_exp} + ${vect_outer_arg2})"; } if ( $outer_inv == 1 ) { $outer_exp = "(not:${mode} $outer_exp)"; + $vect_outer_exp = "(not:${mode} $vect_outer_exp)"; } - $insn = <<"EOF"; + # See if we can use xxeval on vector fusion + $xxeval = $xxeval_fusions{"${inner_op}_${outer_name}"}; + if (!$xxeval) { + $insn = <<"EOF"; ;; $ftype fusion pattern generated by gen_logical_addsubf ;; $kind $inner_op -> $outer_name @@ -318,6 +344,30 @@ sub gen_logical_addsubf (set_attr "length" "8")]) EOF + } else { + $insn = <<"EOF"; + +;; $ftype fusion pattern generated by gen_logical_addsubf +;; $kind $inner_op -> $outer_name +(define_insn "*fuse_${inner_op}_${outer_name}" + [(set (match_operand:${mode} 3 "${vect_pred}" "=&0,&1,&${constraint},wa,${constraint}") + ${vect_outer_exp}) + (clobber (match_scratch:${mode} 4 "=X,X,X,X,&${constraint}"))] + "(TARGET_P10_FUSION)" + "@ + ${inner_op} %3,%1,%0\\;${outer_op} %3,${outer_32} + ${inner_op} %3,%1,%0\\;${outer_op} %3,${outer_32} + ${inner_op} %3,%1,%0\\;${outer_op} %3,${outer_32} + xxeval %x3,%x2,%x1,%x0,${xxeval} + ${inner_op} %4,%1,%0\\;${outer_op} %3,${outer_42}" + [(set_attr "type" "$fuse_type") + (set_attr "cost" "6") + (set_attr "length" "8") + (set_attr "prefixed" "*,*,*,yes,*") + (set_attr "isa" "*,*,*,xxeval,*")]) +EOF + } + print $insn; } } diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md index 647e89afb6a..a6010a8c8a8 100644 --- a/gcc/config/rs6000/predicates.md +++ b/gcc/config/rs6000/predicates.md @@ -119,6 +119,18 @@ (define_predicate "vsx_reg_sfsubreg_ok" return VSX_REGNO_P (REGNO (op)); }) +;; Return 1 if op is a register that can be used for vector fusion. If XXEVAL +;; is supported, return true for all VSX registers, otherwise the fusion is +;; limited to Altivec registers since the machine only fuses Altivec +;; operations. +(define_predicate "vector_fusion_operand" + (match_operand 0 "register_operand") +{ + return (TARGET_XXEVAL + ? vsx_register_operand (op, mode) + : altivec_register_operand (op, mode)); +}) + ;; Return 1 if op is a vector register that operates on floating point vectors ;; (either altivec or VSX). (define_predicate "vfloat_operand" diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h index 9267612fbc9..0430876eea8 100644 --- a/gcc/config/rs6000/rs6000.h +++ b/gcc/config/rs6000/rs6000.h @@ -500,6 +500,10 @@ extern int rs6000_vector_align[]; #define TARGET_MINMAX (TARGET_HARD_FLOAT && TARGET_PPC_GFXOPT \ && (TARGET_P9_MINMAX || !flag_trapping_math)) +/* Enable XXEVAL support if we support prefixed instructions and at least + power10. */ +#define TARGET_XXEVAL (TARGET_POWER10 && TARGET_PREFIXED) + /* In the past we represented the various power cpus (power4, power5, power6, etc.) via ISA bits that highlighted a new instruction or we used an extra option to represent the hardware (i.e. -mpower8-internal or -mpower10). Now diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 4c2bc81caf5..3b876462ec3 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -369,7 +369,7 @@ (define_attr "cpu" (const (symbol_ref "(enum attr_cpu) rs6000_tune"))) ;; The ISA we implement. -(define_attr "isa" "any,p5,p6,p7,p7v,p8,p8v,p9,p9v,p9kf,p9tf,p10" +(define_attr "isa" "any,p5,p6,p7,p7v,p8,p8v,p9,p9v,p9kf,p9tf,p10,xxeval" (const_string "any")) ;; Is this alternative enabled for the current CPU/ISA/etc.? @@ -421,6 +421,11 @@ (define_attr "enabled" "" (and (eq_attr "isa" "p10") (match_test "TARGET_POWER10")) (const_int 1) + + (and (eq_attr "isa" "xxeval") + (match_test "TARGET_PREFIXED && TARGET_XXEVAL")) + (const_int 1) + ] (const_int 0))) ;; If this instruction is microcoded on the CELL processor -- 2.49.0 -- Michael Meissner, IBM PO Box 98, Ayer, Massachusetts, USA, 01432 email: meiss...@linux.ibm.com
