[llvm] r304235 - [LV] Reapply r303763 with fix for PR33193
Matthew Simpson via llvm-commits
llvm-commits at lists.llvm.org
Tue May 30 12:55:57 PDT 2017
Author: mssimpso
Date: Tue May 30 14:55:57 2017
New Revision: 304235
URL: http://llvm.org/viewvc/llvm-project?rev=304235&view=rev
Log:
[LV] Reapply r303763 with fix for PR33193
r303763 caused build failures in some out-of-tree tests due to an assertion in
TTI. The original patch updated cost estimates for induction variable update
instructions marked for scalarization. However, it didn't consider that the
incoming value of an induction variable phi node could be a cast instruction.
This caused queries for cast instruction costs with a mix of vector and scalar
types. This patch includes a fix for cast instructions and the test case from
PR33193.
The fix was suggested by Jonas Paulsson <paulsson at linux.vnet.ibm.com>.
Reference: https://bugs.llvm.org/show_bug.cgi?id=33193
Original Differential Revision: https://reviews.llvm.org/D33457
Added:
llvm/trunk/test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll
Modified:
llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=304235&r1=304234&r2=304235&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Tue May 30 14:55:57 2017
@@ -7170,10 +7170,8 @@ LoopVectorizationCostModel::getInstructi
Type *VectorTy;
unsigned C = getInstructionCost(I, VF, VectorTy);
- // Note: Even if all instructions are scalarized, return true if any memory
- // accesses appear in the loop to get benefits from address folding etc.
bool TypeNotScalarized =
- VF > 1 && !VectorTy->isVoidTy() && TTI.getNumberOfParts(VectorTy) < VF;
+ VF > 1 && VectorTy->isVectorTy() && TTI.getNumberOfParts(VectorTy) < VF;
return VectorizationCostTy(C, TypeNotScalarized);
}
@@ -7312,7 +7310,7 @@ unsigned LoopVectorizationCostModel::get
Type *RetTy = I->getType();
if (canTruncateToMinimalBitwidth(I, VF))
RetTy = IntegerType::get(RetTy->getContext(), MinBWs[I]);
- VectorTy = ToVectorTy(RetTy, VF);
+ VectorTy = isScalarAfterVectorization(I, VF) ? RetTy : ToVectorTy(RetTy, VF);
auto SE = PSE.getSE();
// TODO: We need to estimate the cost of intrinsic calls.
@@ -7445,9 +7443,10 @@ unsigned LoopVectorizationCostModel::get
} else if (Legal->isUniform(Op2)) {
Op2VK = TargetTransformInfo::OK_UniformValue;
}
- SmallVector<const Value *, 4> Operands(I->operand_values());
- return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK,
- Op2VK, Op1VP, Op2VP, Operands);
+ SmallVector<const Value *, 4> Operands(I->operand_values());
+ unsigned N = isScalarAfterVectorization(I, VF) ? VF : 1;
+ return N * TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK,
+ Op2VK, Op1VP, Op2VP, Operands);
}
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
@@ -7470,7 +7469,15 @@ unsigned LoopVectorizationCostModel::get
}
case Instruction::Store:
case Instruction::Load: {
- VectorTy = ToVectorTy(getMemInstValueType(I), VF);
+ unsigned Width = VF;
+ if (Width > 1) {
+ InstWidening Decision = getWideningDecision(I, Width);
+ assert(Decision != CM_Unknown &&
+ "CM decision should be taken at this point");
+ if (Decision == CM_Scalarize)
+ Width = 1;
+ }
+ VectorTy = ToVectorTy(getMemInstValueType(I), Width);
return getMemoryInstructionCost(I, VF);
}
case Instruction::ZExt:
@@ -7495,7 +7502,8 @@ unsigned LoopVectorizationCostModel::get
}
Type *SrcScalarTy = I->getOperand(0)->getType();
- Type *SrcVecTy = ToVectorTy(SrcScalarTy, VF);
+ Type *SrcVecTy =
+ VectorTy->isVectorTy() ? ToVectorTy(SrcScalarTy, VF) : SrcScalarTy;
if (canTruncateToMinimalBitwidth(I, VF)) {
// This cast is going to be shrunk. This may remove the cast or it might
// turn it into slightly different cast. For example, if MinBW == 16,
@@ -7515,7 +7523,8 @@ unsigned LoopVectorizationCostModel::get
}
}
- return TTI.getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy, I);
+ unsigned N = isScalarAfterVectorization(I, VF) ? VF : 1;
+ return N * TTI.getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy, I);
}
case Instruction::Call: {
bool NeedToScalarize;
Added: llvm/trunk/test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll?rev=304235&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll (added)
+++ llvm/trunk/test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll Tue May 30 14:55:57 2017
@@ -0,0 +1,49 @@
+; REQUIRES: asserts
+; RUN: opt < %s -loop-vectorize -force-vector-interleave=1 -S -debug-only=loop-vectorize 2>&1 | FileCheck %s
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64--linux-gnu"
+
+; CHECK-LABEL: all_scalar
+; CHECK: LV: Found scalar instruction: %i.next = add nuw nsw i64 %i, 2
+; CHECK: LV: Found an estimated cost of 2 for VF 2 For instruction: %i.next = add nuw nsw i64 %i, 2
+; CHECK: LV: Not considering vector loop of width 2 because it will not generate any vector instructions
+;
+define void @all_scalar(i64* %a, i64 %n) {
+entry:
+ br label %for.body
+
+for.body:
+ %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
+ %tmp0 = getelementptr i64, i64* %a, i64 %i
+ store i64 0, i64* %tmp0, align 1
+ %i.next = add nuw nsw i64 %i, 2
+ %cond = icmp eq i64 %i.next, %n
+ br i1 %cond, label %for.end, label %for.body
+
+for.end:
+ ret void
+}
+
+; CHECK-LABEL: PR33193
+; CHECK: LV: Found scalar instruction: %i.next = zext i32 %j.next to i64
+; CHECK: LV: Found an estimated cost of 0 for VF 8 For instruction: %i.next = zext i32 %j.next to i64
+; CHECK: LV: Not considering vector loop of width 8 because it will not generate any vector instructions
+%struct.a = type { i32, i8 }
+define void @PR33193(%struct.a* %a, i64 %n) {
+entry:
+ br label %for.body
+
+for.body:
+ %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
+ %j = phi i32 [ 0, %entry ], [ %j.next, %for.body ]
+ %tmp0 = getelementptr inbounds %struct.a, %struct.a* %a, i64 %i, i32 1
+ store i8 0, i8* %tmp0, align 4
+ %j.next = add i32 %j, 1
+ %i.next = zext i32 %j.next to i64
+ %cond = icmp ugt i64 %n, %i.next
+ br i1 %cond, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
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