[llvm] r213452 - [LoopVectorize] Propagate known metadata to vectorized instructions
Hal Finkel
hfinkel at anl.gov
Sat Jul 19 06:33:18 PDT 2014
Author: hfinkel
Date: Sat Jul 19 08:33:16 2014
New Revision: 213452
URL: http://llvm.org/viewvc/llvm-project?rev=213452&view=rev
Log:
[LoopVectorize] Propagate known metadata to vectorized instructions
There are some kinds of metadata that are safe to propagate from the scalar
instructions to the vector instructions (fpmath and tbaa currently).
Regarding TBAA, one might worry about propagating it on if-converted loads and
stores, because the metadata might have had a control dependency on the
condition, and thus actually aliased with some other non-speculated memory
access when the condition was false. However, this would be caught by the
runtime overlap checks.
Added:
llvm/trunk/test/Transforms/LoopVectorize/metadata.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=213452&r1=213451&r2=213452&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Sat Jul 19 08:33:16 2014
@@ -518,6 +518,34 @@ static std::string getDebugLocString(con
}
#endif
+/// \brief Propagate known metadata from one instruction to another.
+static void propagateMetadata(Instruction *To, const Instruction *From) {
+ SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
+ From->getAllMetadataOtherThanDebugLoc(Metadata);
+
+ for (auto M : Metadata) {
+ unsigned Kind = M.first;
+
+ // These are safe to transfer (this is safe for TBAA, even when we
+ // if-convert, because should that metadata have had a control dependency
+ // on the condition, and thus actually aliased with some other
+ // non-speculated memory access when the condition was false, this would be
+ // caught by the runtime overlap checks).
+ if (Kind != LLVMContext::MD_tbaa &&
+ Kind != LLVMContext::MD_fpmath)
+ continue;
+
+ To->setMetadata(Kind, M.second);
+ }
+}
+
+/// \brief Propagate known metadata from one instruction to a vector of others.
+static void propagateMetadata(SmallVectorImpl<Value *> &To, const Instruction *From) {
+ for (Value *V : To)
+ if (Instruction *I = dyn_cast<Instruction>(V))
+ propagateMetadata(I, From);
+}
+
/// LoopVectorizationLegality checks if it is legal to vectorize a loop, and
/// to what vectorization factor.
/// This class does not look at the profitability of vectorization, only the
@@ -1734,7 +1762,9 @@ void InnerLoopVectorizer::vectorizeMemor
Value *VecPtr = Builder.CreateBitCast(PartPtr,
DataTy->getPointerTo(AddressSpace));
- Builder.CreateStore(StoredVal[Part], VecPtr)->setAlignment(Alignment);
+ StoreInst *NewSI = Builder.CreateStore(StoredVal[Part], VecPtr);
+ NewSI->setAlignment(Alignment);
+ propagateMetadata(NewSI, SI);
}
return;
}
@@ -1755,9 +1785,10 @@ void InnerLoopVectorizer::vectorizeMemor
Value *VecPtr = Builder.CreateBitCast(PartPtr,
DataTy->getPointerTo(AddressSpace));
- Value *LI = Builder.CreateLoad(VecPtr, "wide.load");
- cast<LoadInst>(LI)->setAlignment(Alignment);
- Entry[Part] = Reverse ? reverseVector(LI) : LI;
+ LoadInst *NewLI = Builder.CreateLoad(VecPtr, "wide.load");
+ NewLI->setAlignment(Alignment);
+ propagateMetadata(NewLI, LI);
+ Entry[Part] = Reverse ? reverseVector(NewLI) : NewLI;
}
}
@@ -3135,6 +3166,8 @@ void InnerLoopVectorizer::vectorizeBlock
Entry[Part] = V;
}
+
+ propagateMetadata(Entry, it);
break;
}
case Instruction::Select: {
@@ -3162,6 +3195,8 @@ void InnerLoopVectorizer::vectorizeBlock
Op0[Part],
Op1[Part]);
}
+
+ propagateMetadata(Entry, it);
break;
}
@@ -3181,6 +3216,8 @@ void InnerLoopVectorizer::vectorizeBlock
C = Builder.CreateICmp(Cmp->getPredicate(), A[Part], B[Part]);
Entry[Part] = C;
}
+
+ propagateMetadata(Entry, it);
break;
}
@@ -3213,6 +3250,7 @@ void InnerLoopVectorizer::vectorizeBlock
Value *Broadcasted = getBroadcastInstrs(ScalarCast);
for (unsigned Part = 0; Part < UF; ++Part)
Entry[Part] = getConsecutiveVector(Broadcasted, VF * Part, false);
+ propagateMetadata(Entry, it);
break;
}
/// Vectorize casts.
@@ -3222,6 +3260,7 @@ void InnerLoopVectorizer::vectorizeBlock
VectorParts &A = getVectorValue(it->getOperand(0));
for (unsigned Part = 0; Part < UF; ++Part)
Entry[Part] = Builder.CreateCast(CI->getOpcode(), A[Part], DestTy);
+ propagateMetadata(Entry, it);
break;
}
@@ -3259,6 +3298,8 @@ void InnerLoopVectorizer::vectorizeBlock
Function *F = Intrinsic::getDeclaration(M, ID, Tys);
Entry[Part] = Builder.CreateCall(F, Args);
}
+
+ propagateMetadata(Entry, it);
break;
}
break;
Added: llvm/trunk/test/Transforms/LoopVectorize/metadata.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/metadata.ll?rev=213452&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/metadata.ll (added)
+++ llvm/trunk/test/Transforms/LoopVectorize/metadata.ll Sat Jul 19 08:33:16 2014
@@ -0,0 +1,44 @@
+; RUN: opt < %s -loop-vectorize -force-vector-unroll=1 -force-vector-width=4 -S | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: nounwind uwtable
+define i32 @test1(i32* nocapture %a, float* nocapture readonly %b) #0 {
+entry:
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+ %arrayidx = getelementptr inbounds float* %b, i64 %indvars.iv
+ %0 = load float* %arrayidx, align 4, !tbaa !0
+ %conv = fptosi float %0 to i32
+ %arrayidx2 = getelementptr inbounds i32* %a, i64 %indvars.iv
+ store i32 %conv, i32* %arrayidx2, align 4, !tbaa !4
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %exitcond = icmp eq i64 %indvars.iv.next, 1600
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+ ret i32 0
+}
+
+; CHECK-LABEL: @test1
+; CHECK: load <4 x float>* %{{.*}}, align 4, !tbaa ![[TFLT:[0-9]+]]
+; CHECK: store <4 x i32> %{{.*}}, <4 x i32>* %{{.*}}, align 4, !tbaa ![[TINT:[0-9]+]]
+; CHECK: ret i32 0
+
+; CHECK-DAG: ![[TFLT]] = metadata !{metadata ![[TFLT1:[0-9]+]]
+; CHECK-DAG: ![[TFLT1]] = metadata !{metadata !"float"
+
+; CHECK-DAG: ![[TINT]] = metadata !{metadata ![[TINT1:[0-9]+]]
+; CHECK-DAG: ![[TINT1]] = metadata !{metadata !"int"
+
+attributes #0 = { nounwind uwtable }
+
+!0 = metadata !{metadata !1, metadata !1, i64 0}
+!1 = metadata !{metadata !"float", metadata !2, i64 0}
+!2 = metadata !{metadata !"omnipotent char", metadata !3, i64 0}
+!3 = metadata !{metadata !"Simple C/C++ TBAA"}
+!4 = metadata !{metadata !5, metadata !5, i64 0}
+!5 = metadata !{metadata !"int", metadata !2, i64 0}
+
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