[llvm] 036207d - [SLP]Improve splat detection.
Alexey Bataev via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 15 07:51:08 PST 2021
Author: Alexey Bataev
Date: 2021-11-15T07:50:34-08:00
New Revision: 036207d5f261b6d60913cfa705b5432630126f40
URL: https://github.com/llvm/llvm-project/commit/036207d5f261b6d60913cfa705b5432630126f40
DIFF: https://github.com/llvm/llvm-project/commit/036207d5f261b6d60913cfa705b5432630126f40.diff
LOG: [SLP]Improve splat detection.
A bunch of scalars can be treated as a splat not only if all elements
are the same but also if some of them are undefvalues.
Differential Revision: https://reviews.llvm.org/D113774
Added:
Modified:
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 63ceda6d89a8..93be0a3f4190 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -254,12 +254,21 @@ static bool allConstant(ArrayRef<Value *> VL) {
return all_of(VL, isConstant);
}
-/// \returns True if all of the values in \p VL are identical.
+/// \returns True if all of the values in \p VL are identical or some of them
+/// are UndefValue.
static bool isSplat(ArrayRef<Value *> VL) {
- for (unsigned i = 1, e = VL.size(); i < e; ++i)
- if (VL[i] != VL[0])
+ Value *FirstNonUndef = nullptr;
+ for (Value *V : VL) {
+ if (isa<UndefValue>(V))
+ continue;
+ if (!FirstNonUndef) {
+ FirstNonUndef = V;
+ continue;
+ }
+ if (V != FirstNonUndef)
return false;
- return true;
+ }
+ return FirstNonUndef != nullptr;
}
/// \returns True if \p I is commutative, handles CmpInst and BinaryOperator.
diff --git a/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll b/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
index e28362894910..f36d8cbe1f3f 100644
--- a/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
+++ b/llvm/test/Transforms/SLPVectorizer/X86/pr35497.ll
@@ -69,32 +69,27 @@ define void @pr35497() local_unnamed_addr #0 {
; SSE-LABEL: @pr35497(
; SSE-NEXT: entry:
; SSE-NEXT: [[TMP0:%.*]] = load i64, i64* undef, align 1
-; SSE-NEXT: [[AND:%.*]] = shl i64 [[TMP0]], 2
-; SSE-NEXT: [[SHL:%.*]] = and i64 [[AND]], 20
; SSE-NEXT: [[ADD:%.*]] = add i64 undef, undef
; SSE-NEXT: store i64 [[ADD]], i64* undef, align 1
; SSE-NEXT: [[ARRAYIDX2_1:%.*]] = getelementptr inbounds [0 x i64], [0 x i64]* undef, i64 0, i64 5
-; SSE-NEXT: [[AND_1:%.*]] = shl i64 undef, 2
-; SSE-NEXT: [[SHL_1:%.*]] = and i64 [[AND_1]], 20
-; SSE-NEXT: [[SHR_1:%.*]] = lshr i64 undef, 6
-; SSE-NEXT: [[ADD_1:%.*]] = add nuw nsw i64 [[SHL]], [[SHR_1]]
+; SSE-NEXT: [[TMP1:%.*]] = insertelement <2 x i64> <i64 undef, i64 poison>, i64 [[TMP0]], i32 1
+; SSE-NEXT: [[TMP2:%.*]] = shl <2 x i64> [[TMP1]], <i64 2, i64 2>
+; SSE-NEXT: [[TMP3:%.*]] = and <2 x i64> [[TMP2]], <i64 20, i64 20>
; SSE-NEXT: [[ARRAYIDX2_2:%.*]] = getelementptr inbounds [0 x i64], [0 x i64]* undef, i64 0, i64 4
-; SSE-NEXT: [[SHR_2:%.*]] = lshr i64 undef, 6
-; SSE-NEXT: [[ADD_2:%.*]] = add nuw nsw i64 [[SHL_1]], [[SHR_2]]
-; SSE-NEXT: [[AND_4:%.*]] = shl i64 [[ADD]], 2
-; SSE-NEXT: [[SHL_4:%.*]] = and i64 [[AND_4]], 20
+; SSE-NEXT: [[TMP4:%.*]] = add nuw nsw <2 x i64> [[TMP3]], zeroinitializer
; SSE-NEXT: [[ARRAYIDX2_5:%.*]] = getelementptr inbounds [0 x i64], [0 x i64]* undef, i64 0, i64 1
-; SSE-NEXT: store i64 [[ADD_1]], i64* [[ARRAYIDX2_5]], align 1
-; SSE-NEXT: [[AND_5:%.*]] = shl nuw nsw i64 [[ADD_1]], 2
-; SSE-NEXT: [[SHL_5:%.*]] = and i64 [[AND_5]], 20
-; SSE-NEXT: [[SHR_5:%.*]] = lshr i64 [[ADD_1]], 6
-; SSE-NEXT: [[ADD_5:%.*]] = add nuw nsw i64 [[SHL_4]], [[SHR_5]]
-; SSE-NEXT: store i64 [[ADD_5]], i64* [[ARRAYIDX2_1]], align 1
+; SSE-NEXT: [[TMP5:%.*]] = extractelement <2 x i64> [[TMP4]], i32 1
+; SSE-NEXT: [[TMP6:%.*]] = insertelement <2 x i64> poison, i64 [[TMP5]], i32 0
+; SSE-NEXT: [[TMP7:%.*]] = insertelement <2 x i64> [[TMP6]], i64 [[ADD]], i32 1
+; SSE-NEXT: [[TMP8:%.*]] = shl <2 x i64> [[TMP7]], <i64 2, i64 2>
+; SSE-NEXT: [[TMP9:%.*]] = and <2 x i64> [[TMP8]], <i64 20, i64 20>
; SSE-NEXT: [[ARRAYIDX2_6:%.*]] = getelementptr inbounds [0 x i64], [0 x i64]* undef, i64 0, i64 0
-; SSE-NEXT: store i64 [[ADD_2]], i64* [[ARRAYIDX2_6]], align 1
-; SSE-NEXT: [[SHR_6:%.*]] = lshr i64 [[ADD_2]], 6
-; SSE-NEXT: [[ADD_6:%.*]] = add nuw nsw i64 [[SHL_5]], [[SHR_6]]
-; SSE-NEXT: store i64 [[ADD_6]], i64* [[ARRAYIDX2_2]], align 1
+; SSE-NEXT: [[TMP10:%.*]] = bitcast i64* [[ARRAYIDX2_6]] to <2 x i64>*
+; SSE-NEXT: store <2 x i64> [[TMP4]], <2 x i64>* [[TMP10]], align 1
+; SSE-NEXT: [[TMP11:%.*]] = lshr <2 x i64> [[TMP4]], <i64 6, i64 6>
+; SSE-NEXT: [[TMP12:%.*]] = add nuw nsw <2 x i64> [[TMP9]], [[TMP11]]
+; SSE-NEXT: [[TMP13:%.*]] = bitcast i64* [[ARRAYIDX2_2]] to <2 x i64>*
+; SSE-NEXT: store <2 x i64> [[TMP12]], <2 x i64>* [[TMP13]], align 1
; SSE-NEXT: ret void
;
; AVX-LABEL: @pr35497(
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