[llvm] 8d830f8 - [LV] Replace fixed-order cost model with a SK_Splice shuffle
David Green via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 24 05:00:48 PDT 2022
Author: David Green
Date: 2022-08-24T13:00:32+01:00
New Revision: 8d830f8d68d19e9b654ec61a20bf43302068e43a
URL: https://github.com/llvm/llvm-project/commit/8d830f8d68d19e9b654ec61a20bf43302068e43a
DIFF: https://github.com/llvm/llvm-project/commit/8d830f8d68d19e9b654ec61a20bf43302068e43a.diff
LOG: [LV] Replace fixed-order cost model with a SK_Splice shuffle
The existing cost model for fixed-order recurrences models the phi as an
extract shuffle of a v1 vector. The shuffle produced should be a splice,
as they take two vectors inputs are extracting from a subset of the
lanes. On certain architectures the existing cost model can drastically
under-estimate the correct cost for the shuffle, so this changes it to a
SK_Splice and passes a correct Mask through to the getShuffleCost call.
I believe this might be the first use of a SK_Splice shuffle cost model
outside of scalable vectors, and some targets may require additions to
the cost-model to correctly account for them. In tree targets appear to
all have been updated where needed.
Differential Revision: https://reviews.llvm.org/D132308
Added:
Modified:
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/test/Transforms/LoopVectorize/ARM/mve-recurrence.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 39783e90d43dc..581e4d2b39c1d 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -7035,12 +7035,13 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, ElementCount VF,
auto *Phi = cast<PHINode>(I);
// First-order recurrences are replaced by vector shuffles inside the loop.
- // NOTE: Don't use ToVectorTy as SK_ExtractSubvector expects a vector type.
- if (VF.isVector() && Legal->isFixedOrderRecurrence(Phi))
- return TTI.getShuffleCost(TargetTransformInfo::SK_ExtractSubvector,
- cast<VectorType>(VectorTy), None, CostKind,
- VF.getKnownMinValue() - 1,
- FixedVectorType::get(RetTy, 1));
+ if (VF.isVector() && Legal->isFixedOrderRecurrence(Phi)) {
+ SmallVector<int> Mask(VF.getKnownMinValue());
+ std::iota(Mask.begin(), Mask.end(), VF.getKnownMinValue() - 1);
+ return TTI.getShuffleCost(TargetTransformInfo::SK_Splice,
+ cast<VectorType>(VectorTy), Mask, CostKind,
+ VF.getKnownMinValue() - 1);
+ }
// Phi nodes in non-header blocks (not inductions, reductions, etc.) are
// converted into select instructions. We require N - 1 selects per phi
diff --git a/llvm/test/Transforms/LoopVectorize/ARM/mve-recurrence.ll b/llvm/test/Transforms/LoopVectorize/ARM/mve-recurrence.ll
index 23f81c21cdb6b..2e4ff928e32f2 100644
--- a/llvm/test/Transforms/LoopVectorize/ARM/mve-recurrence.ll
+++ b/llvm/test/Transforms/LoopVectorize/ARM/mve-recurrence.ll
@@ -15,55 +15,22 @@ define void @firstorderrec(ptr nocapture noundef readonly %x, ptr noalias nocapt
; CHECK: for.body.preheader:
; CHECK-NEXT: [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[N]] to i64
; CHECK-NEXT: [[DOTPRE:%.*]] = load i8, ptr [[X:%.*]], align 1
-; CHECK-NEXT: [[TMP0:%.*]] = add nsw i64 [[WIDE_TRIP_COUNT]], -1
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP0]], 16
-; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
-; CHECK: vector.ph:
-; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[TMP0]], 16
-; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF]]
-; CHECK-NEXT: [[IND_END:%.*]] = add i64 1, [[N_VEC]]
-; CHECK-NEXT: [[VECTOR_RECUR_INIT:%.*]] = insertelement <16 x i8> poison, i8 [[DOTPRE]], i32 15
-; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
-; CHECK: vector.body:
-; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[VECTOR_RECUR:%.*]] = phi <16 x i8> [ [[VECTOR_RECUR_INIT]], [[VECTOR_PH]] ], [ [[WIDE_LOAD:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[OFFSET_IDX:%.*]] = add i64 1, [[INDEX]]
-; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[OFFSET_IDX]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = getelementptr inbounds i8, ptr [[X]], i64 [[TMP1]]
-; CHECK-NEXT: [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[TMP2]], i32 0
-; CHECK-NEXT: [[WIDE_LOAD]] = load <16 x i8>, ptr [[TMP3]], align 1
-; CHECK-NEXT: [[TMP4:%.*]] = shufflevector <16 x i8> [[VECTOR_RECUR]], <16 x i8> [[WIDE_LOAD]], <16 x i32> <i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30>
-; CHECK-NEXT: [[TMP5:%.*]] = add <16 x i8> [[WIDE_LOAD]], [[TMP4]]
-; CHECK-NEXT: [[TMP6:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 [[TMP1]]
-; CHECK-NEXT: [[TMP7:%.*]] = getelementptr inbounds i8, ptr [[TMP6]], i32 0
-; CHECK-NEXT: store <16 x i8> [[TMP5]], ptr [[TMP7]], align 1
-; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
-; CHECK-NEXT: [[TMP8:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP8]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
-; CHECK: middle.block:
-; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[TMP0]], [[N_VEC]]
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <16 x i8> [[WIDE_LOAD]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT_FOR_PHI:%.*]] = extractelement <16 x i8> [[WIDE_LOAD]], i32 14
-; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]], label [[SCALAR_PH]]
-; CHECK: scalar.ph:
-; CHECK-NEXT: [[SCALAR_RECUR_INIT:%.*]] = phi i8 [ [[DOTPRE]], [[FOR_BODY_PREHEADER]] ], [ [[VECTOR_RECUR_EXTRACT]], [[MIDDLE_BLOCK]] ]
-; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ 1, [[FOR_BODY_PREHEADER]] ]
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.cond.cleanup.loopexit:
; CHECK-NEXT: br label [[FOR_COND_CLEANUP]]
; CHECK: for.cond.cleanup:
; CHECK-NEXT: ret void
; CHECK: for.body:
-; CHECK-NEXT: [[SCALAR_RECUR:%.*]] = phi i8 [ [[SCALAR_RECUR_INIT]], [[SCALAR_PH]] ], [ [[TMP9:%.*]], [[FOR_BODY]] ]
-; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = phi i8 [ [[DOTPRE]], [[FOR_BODY_PREHEADER]] ], [ [[TMP1:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ 1, [[FOR_BODY_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT: [[ARRAYIDX4:%.*]] = getelementptr inbounds i8, ptr [[X]], i64 [[INDVARS_IV]]
-; CHECK-NEXT: [[TMP9]] = load i8, ptr [[ARRAYIDX4]], align 1
-; CHECK-NEXT: [[ADD7:%.*]] = add i8 [[TMP9]], [[SCALAR_RECUR]]
-; CHECK-NEXT: [[ARRAYIDX10:%.*]] = getelementptr inbounds i8, ptr [[Y]], i64 [[INDVARS_IV]]
+; CHECK-NEXT: [[TMP1]] = load i8, ptr [[ARRAYIDX4]], align 1
+; CHECK-NEXT: [[ADD7:%.*]] = add i8 [[TMP1]], [[TMP0]]
+; CHECK-NEXT: [[ARRAYIDX10:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 [[INDVARS_IV]]
; CHECK-NEXT: store i8 [[ADD7]], ptr [[ARRAYIDX10]], align 1
; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT]], [[WIDE_TRIP_COUNT]]
-; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP_LOOPEXIT]], label [[FOR_BODY]], !llvm.loop [[LOOP2:![0-9]+]]
+; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]], label [[FOR_BODY]]
;
entry:
%cmp18 = icmp sgt i32 %n, 1
@@ -102,73 +69,26 @@ define void @thirdorderrec(ptr nocapture noundef readonly %x, ptr noalias nocapt
; CHECK-NEXT: [[DOTPRE44:%.*]] = load i8, ptr [[ARRAYIDX5_PHI_TRANS_INSERT]], align 1
; CHECK-NEXT: [[ARRAYIDX12_PHI_TRANS_INSERT:%.*]] = getelementptr inbounds i8, ptr [[X]], i64 2
; CHECK-NEXT: [[DOTPRE45:%.*]] = load i8, ptr [[ARRAYIDX12_PHI_TRANS_INSERT]], align 1
-; CHECK-NEXT: [[TMP0:%.*]] = add nsw i64 [[WIDE_TRIP_COUNT]], -3
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP0]], 16
-; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
-; CHECK: vector.ph:
-; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[TMP0]], 16
-; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF]]
-; CHECK-NEXT: [[IND_END:%.*]] = add i64 3, [[N_VEC]]
-; CHECK-NEXT: [[VECTOR_RECUR_INIT:%.*]] = insertelement <16 x i8> poison, i8 [[DOTPRE45]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_INIT1:%.*]] = insertelement <16 x i8> poison, i8 [[DOTPRE44]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_INIT3:%.*]] = insertelement <16 x i8> poison, i8 [[DOTPRE]], i32 15
-; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
-; CHECK: vector.body:
-; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[VECTOR_RECUR:%.*]] = phi <16 x i8> [ [[VECTOR_RECUR_INIT]], [[VECTOR_PH]] ], [ [[WIDE_LOAD:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[VECTOR_RECUR2:%.*]] = phi <16 x i8> [ [[VECTOR_RECUR_INIT1]], [[VECTOR_PH]] ], [ [[TMP4:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[VECTOR_RECUR4:%.*]] = phi <16 x i8> [ [[VECTOR_RECUR_INIT3]], [[VECTOR_PH]] ], [ [[TMP5:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[OFFSET_IDX:%.*]] = add i64 3, [[INDEX]]
-; CHECK-NEXT: [[TMP1:%.*]] = add i64 [[OFFSET_IDX]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = getelementptr inbounds i8, ptr [[X]], i64 [[TMP1]]
-; CHECK-NEXT: [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[TMP2]], i32 0
-; CHECK-NEXT: [[WIDE_LOAD]] = load <16 x i8>, ptr [[TMP3]], align 1
-; CHECK-NEXT: [[TMP4]] = shufflevector <16 x i8> [[VECTOR_RECUR]], <16 x i8> [[WIDE_LOAD]], <16 x i32> <i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30>
-; CHECK-NEXT: [[TMP5]] = shufflevector <16 x i8> [[VECTOR_RECUR2]], <16 x i8> [[TMP4]], <16 x i32> <i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30>
-; CHECK-NEXT: [[TMP6:%.*]] = shufflevector <16 x i8> [[VECTOR_RECUR4]], <16 x i8> [[TMP5]], <16 x i32> <i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30>
-; CHECK-NEXT: [[TMP7:%.*]] = add <16 x i8> [[TMP5]], [[TMP6]]
-; CHECK-NEXT: [[TMP8:%.*]] = add <16 x i8> [[TMP7]], [[TMP4]]
-; CHECK-NEXT: [[TMP9:%.*]] = add <16 x i8> [[TMP8]], [[WIDE_LOAD]]
-; CHECK-NEXT: [[TMP10:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 [[TMP1]]
-; CHECK-NEXT: [[TMP11:%.*]] = getelementptr inbounds i8, ptr [[TMP10]], i32 0
-; CHECK-NEXT: store <16 x i8> [[TMP9]], ptr [[TMP11]], align 1
-; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
-; CHECK-NEXT: [[TMP12:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP12]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
-; CHECK: middle.block:
-; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[TMP0]], [[N_VEC]]
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <16 x i8> [[WIDE_LOAD]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT_FOR_PHI:%.*]] = extractelement <16 x i8> [[WIDE_LOAD]], i32 14
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT5:%.*]] = extractelement <16 x i8> [[TMP4]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT_FOR_PHI6:%.*]] = extractelement <16 x i8> [[TMP4]], i32 14
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT9:%.*]] = extractelement <16 x i8> [[TMP5]], i32 15
-; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT_FOR_PHI10:%.*]] = extractelement <16 x i8> [[TMP5]], i32 14
-; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]], label [[SCALAR_PH]]
-; CHECK: scalar.ph:
-; CHECK-NEXT: [[SCALAR_RECUR_INIT11:%.*]] = phi i8 [ [[DOTPRE]], [[FOR_BODY_PREHEADER]] ], [ [[VECTOR_RECUR_EXTRACT9]], [[MIDDLE_BLOCK]] ]
-; CHECK-NEXT: [[SCALAR_RECUR_INIT7:%.*]] = phi i8 [ [[DOTPRE44]], [[FOR_BODY_PREHEADER]] ], [ [[VECTOR_RECUR_EXTRACT5]], [[MIDDLE_BLOCK]] ]
-; CHECK-NEXT: [[SCALAR_RECUR_INIT:%.*]] = phi i8 [ [[DOTPRE45]], [[FOR_BODY_PREHEADER]] ], [ [[VECTOR_RECUR_EXTRACT]], [[MIDDLE_BLOCK]] ]
-; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ 3, [[FOR_BODY_PREHEADER]] ]
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.cond.cleanup.loopexit:
; CHECK-NEXT: br label [[FOR_COND_CLEANUP]]
; CHECK: for.cond.cleanup:
; CHECK-NEXT: ret void
; CHECK: for.body:
-; CHECK-NEXT: [[SCALAR_RECUR:%.*]] = phi i8 [ [[SCALAR_RECUR_INIT]], [[SCALAR_PH]] ], [ [[TMP13:%.*]], [[FOR_BODY]] ]
-; CHECK-NEXT: [[SCALAR_RECUR8:%.*]] = phi i8 [ [[SCALAR_RECUR_INIT7]], [[SCALAR_PH]] ], [ [[SCALAR_RECUR]], [[FOR_BODY]] ]
-; CHECK-NEXT: [[SCALAR_RECUR12:%.*]] = phi i8 [ [[SCALAR_RECUR_INIT11]], [[SCALAR_PH]] ], [ [[SCALAR_RECUR8]], [[FOR_BODY]] ]
-; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
-; CHECK-NEXT: [[ADD8:%.*]] = add i8 [[SCALAR_RECUR8]], [[SCALAR_RECUR12]]
-; CHECK-NEXT: [[ADD15:%.*]] = add i8 [[ADD8]], [[SCALAR_RECUR]]
+; CHECK-NEXT: [[TMP0:%.*]] = phi i8 [ [[DOTPRE45]], [[FOR_BODY_PREHEADER]] ], [ [[TMP3:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[TMP1:%.*]] = phi i8 [ [[DOTPRE44]], [[FOR_BODY_PREHEADER]] ], [ [[TMP0]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[TMP2:%.*]] = phi i8 [ [[DOTPRE]], [[FOR_BODY_PREHEADER]] ], [ [[TMP1]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ 3, [[FOR_BODY_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[ADD8:%.*]] = add i8 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[ADD15:%.*]] = add i8 [[ADD8]], [[TMP0]]
; CHECK-NEXT: [[ARRAYIDX18:%.*]] = getelementptr inbounds i8, ptr [[X]], i64 [[INDVARS_IV]]
-; CHECK-NEXT: [[TMP13]] = load i8, ptr [[ARRAYIDX18]], align 1
-; CHECK-NEXT: [[ADD21:%.*]] = add i8 [[ADD15]], [[TMP13]]
-; CHECK-NEXT: [[ARRAYIDX24:%.*]] = getelementptr inbounds i8, ptr [[Y]], i64 [[INDVARS_IV]]
+; CHECK-NEXT: [[TMP3]] = load i8, ptr [[ARRAYIDX18]], align 1
+; CHECK-NEXT: [[ADD21:%.*]] = add i8 [[ADD15]], [[TMP3]]
+; CHECK-NEXT: [[ARRAYIDX24:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 [[INDVARS_IV]]
; CHECK-NEXT: store i8 [[ADD21]], ptr [[ARRAYIDX24]], align 1
; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT]], [[WIDE_TRIP_COUNT]]
-; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP_LOOPEXIT]], label [[FOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
+; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]], label [[FOR_BODY]]
;
entry:
%cmp38 = icmp sgt i32 %n, 3
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