[llvm] r339875 - [InstCombine] move vector compare before same-shuffled ops
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 16 05:52:17 PDT 2018
Author: spatel
Date: Thu Aug 16 05:52:17 2018
New Revision: 339875
URL: http://llvm.org/viewvc/llvm-project?rev=339875&view=rev
Log:
[InstCombine] move vector compare before same-shuffled ops
This is a step towards fixing PR37463:
https://bugs.llvm.org/show_bug.cgi?id=37463
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=339875&r1=339874&r2=339875&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Thu Aug 16 05:52:17 2018
@@ -4598,6 +4598,26 @@ static Instruction *canonicalizeICmpBool
}
}
+static Instruction *foldVectorCmp(CmpInst &Cmp,
+ InstCombiner::BuilderTy &Builder) {
+ // If both arguments of the cmp are shuffles that use the same mask and
+ // shuffle within a single vector, move the shuffle after the cmp.
+ Value *LHS = Cmp.getOperand(0), *RHS = Cmp.getOperand(1);
+ Value *V1, *V2;
+ Constant *M;
+ if (match(LHS, m_ShuffleVector(m_Value(V1), m_Undef(), m_Constant(M))) &&
+ match(RHS, m_ShuffleVector(m_Value(V2), m_Undef(), m_Specific(M))) &&
+ V1->getType() == V2->getType() &&
+ (LHS->hasOneUse() || RHS->hasOneUse())) {
+ // cmp (shuffle V1, M), (shuffle V2, M) --> shuffle (cmp V1, V2), M
+ CmpInst::Predicate P = Cmp.getPredicate();
+ Value *NewCmp = isa<ICmpInst>(Cmp) ? Builder.CreateICmp(P, V1, V2)
+ : Builder.CreateFCmp(P, V1, V2);
+ return new ShuffleVectorInst(NewCmp, UndefValue::get(NewCmp->getType()), M);
+ }
+ return nullptr;
+}
+
Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
bool Changed = false;
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -4867,6 +4887,10 @@ Instruction *InstCombiner::visitICmpInst
return foldICmpAddOpConst(X, Cst, I.getSwappedPredicate());
}
+ if (I.getType()->isVectorTy())
+ if (Instruction *Res = foldVectorCmp(I, Builder))
+ return Res;
+
return Changed ? &I : nullptr;
}
@@ -5301,5 +5325,9 @@ Instruction *InstCombiner::visitFCmpInst
if (LHSExt->getSrcTy() == RHSExt->getSrcTy())
return new FCmpInst(Pred, LHSExt->getOperand(0), RHSExt->getOperand(0));
+ if (I.getType()->isVectorTy())
+ if (Instruction *Res = foldVectorCmp(I, Builder))
+ return Res;
+
return Changed ? &I : nullptr;
}
Modified: llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll?rev=339875&r1=339874&r2=339875&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll Thu Aug 16 05:52:17 2018
@@ -199,14 +199,12 @@ define <2 x i1> @PR27786(<2 x i8> %a) {
ret <2 x i1> %cmp
}
-; FIXME:
; This is similar to a transform for shuffled binops: compare first, shuffle after.
define <4 x i1> @same_shuffle_inputs_icmp(<4 x i8> %x, <4 x i8> %y) {
; CHECK-LABEL: @same_shuffle_inputs_icmp(
-; CHECK-NEXT: [[SHUFX:%.*]] = shufflevector <4 x i8> [[X:%.*]], <4 x i8> undef, <4 x i32> <i32 3, i32 3, i32 2, i32 0>
-; CHECK-NEXT: [[SHUFY:%.*]] = shufflevector <4 x i8> [[Y:%.*]], <4 x i8> undef, <4 x i32> <i32 3, i32 3, i32 2, i32 0>
-; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <4 x i8> [[SHUFX]], [[SHUFY]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt <4 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 3, i32 3, i32 2, i32 0>
; CHECK-NEXT: ret <4 x i1> [[CMP]]
;
%shufx = shufflevector <4 x i8> %x, <4 x i8> undef, <4 x i32> < i32 3, i32 3, i32 2, i32 0 >
@@ -219,9 +217,8 @@ define <4 x i1> @same_shuffle_inputs_icm
define <5 x i1> @same_shuffle_inputs_fcmp(<4 x float> %x, <4 x float> %y) {
; CHECK-LABEL: @same_shuffle_inputs_fcmp(
-; CHECK-NEXT: [[SHUFX:%.*]] = shufflevector <4 x float> [[X:%.*]], <4 x float> undef, <5 x i32> <i32 0, i32 1, i32 3, i32 2, i32 0>
-; CHECK-NEXT: [[SHUFY:%.*]] = shufflevector <4 x float> [[Y:%.*]], <4 x float> undef, <5 x i32> <i32 0, i32 1, i32 3, i32 2, i32 0>
-; CHECK-NEXT: [[CMP:%.*]] = fcmp oeq <5 x float> [[SHUFX]], [[SHUFY]]
+; CHECK-NEXT: [[TMP1:%.*]] = fcmp oeq <4 x float> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <5 x i32> <i32 0, i32 1, i32 3, i32 2, i32 0>
; CHECK-NEXT: ret <5 x i1> [[CMP]]
;
%shufx = shufflevector <4 x float> %x, <4 x float> undef, <5 x i32> < i32 0, i32 1, i32 3, i32 2, i32 0 >
@@ -235,8 +232,8 @@ declare void @use_v4i8(<4 x i8>)
define <4 x i1> @same_shuffle_inputs_icmp_extra_use1(<4 x i8> %x, <4 x i8> %y) {
; CHECK-LABEL: @same_shuffle_inputs_icmp_extra_use1(
; CHECK-NEXT: [[SHUFX:%.*]] = shufflevector <4 x i8> [[X:%.*]], <4 x i8> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
-; CHECK-NEXT: [[SHUFY:%.*]] = shufflevector <4 x i8> [[Y:%.*]], <4 x i8> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
-; CHECK-NEXT: [[CMP:%.*]] = icmp ugt <4 x i8> [[SHUFX]], [[SHUFY]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt <4 x i8> [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
; CHECK-NEXT: call void @use_v4i8(<4 x i8> [[SHUFX]])
; CHECK-NEXT: ret <4 x i1> [[CMP]]
;
@@ -251,9 +248,9 @@ declare void @use_v2i8(<2 x i8>)
define <2 x i1> @same_shuffle_inputs_icmp_extra_use2(<4 x i8> %x, <4 x i8> %y) {
; CHECK-LABEL: @same_shuffle_inputs_icmp_extra_use2(
-; CHECK-NEXT: [[SHUFX:%.*]] = shufflevector <4 x i8> [[X:%.*]], <4 x i8> undef, <2 x i32> <i32 3, i32 2>
; CHECK-NEXT: [[SHUFY:%.*]] = shufflevector <4 x i8> [[Y:%.*]], <4 x i8> undef, <2 x i32> <i32 3, i32 2>
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i8> [[SHUFX]], [[SHUFY]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq <4 x i8> [[X:%.*]], [[Y]]
+; CHECK-NEXT: [[CMP:%.*]] = shufflevector <4 x i1> [[TMP1]], <4 x i1> undef, <2 x i32> <i32 3, i32 2>
; CHECK-NEXT: call void @use_v2i8(<2 x i8> [[SHUFY]])
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
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