[llvm] r248419 - [InstCombine] Preserve metadata when merging loads that are phi
Akira Hatanaka via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 23 11:40:58 PDT 2015
Author: ahatanak
Date: Wed Sep 23 13:40:57 2015
New Revision: 248419
URL: http://llvm.org/viewvc/llvm-project?rev=248419&view=rev
Log:
[InstCombine] Preserve metadata when merging loads that are phi
arguments.
Make sure InstCombiner::FoldPHIArgLoadIntoPHI doesn't drop the following
metadata:
MD_tbaa
MD_alias_scope
MD_noalias
MD_invariant_load
MD_nonnull
MD_range
rdar://problem/17617709
Differential Revision: http://reviews.llvm.org/D12710
Added:
llvm/trunk/test/Transforms/InstCombine/fold-phi-load-metadata.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp?rev=248419&r1=248418&r2=248419&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombinePHI.cpp Wed Sep 23 13:40:57 2015
@@ -15,6 +15,7 @@
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
#define DEBUG_TYPE "instcombine"
@@ -349,24 +350,37 @@ Instruction *InstCombiner::FoldPHIArgLoa
Value *InVal = FirstLI->getOperand(0);
NewPN->addIncoming(InVal, PN.getIncomingBlock(0));
+ LoadInst *NewLI = new LoadInst(NewPN, "", isVolatile, LoadAlignment);
- // Add all operands to the new PHI.
+ unsigned KnownIDs[] = {
+ LLVMContext::MD_tbaa,
+ LLVMContext::MD_range,
+ LLVMContext::MD_invariant_load,
+ LLVMContext::MD_alias_scope,
+ LLVMContext::MD_noalias,
+ LLVMContext::MD_nonnull
+ };
+
+ for (unsigned ID : KnownIDs)
+ NewLI->setMetadata(ID, FirstLI->getMetadata(ID));
+
+ // Add all operands to the new PHI and combine TBAA metadata.
for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) {
- Value *NewInVal = cast<LoadInst>(PN.getIncomingValue(i))->getOperand(0);
+ LoadInst *LI = cast<LoadInst>(PN.getIncomingValue(i));
+ combineMetadata(NewLI, LI, KnownIDs);
+ Value *NewInVal = LI->getOperand(0);
if (NewInVal != InVal)
InVal = nullptr;
NewPN->addIncoming(NewInVal, PN.getIncomingBlock(i));
}
- Value *PhiVal;
if (InVal) {
// The new PHI unions all of the same values together. This is really
// common, so we handle it intelligently here for compile-time speed.
- PhiVal = InVal;
+ NewLI->setOperand(0, InVal);
delete NewPN;
} else {
InsertNewInstBefore(NewPN, PN);
- PhiVal = NewPN;
}
// If this was a volatile load that we are merging, make sure to loop through
@@ -376,7 +390,6 @@ Instruction *InstCombiner::FoldPHIArgLoa
for (Value *IncValue : PN.incoming_values())
cast<LoadInst>(IncValue)->setVolatile(false);
- LoadInst *NewLI = new LoadInst(PhiVal, "", isVolatile, LoadAlignment);
NewLI->setDebugLoc(FirstLI->getDebugLoc());
return NewLI;
}
Added: llvm/trunk/test/Transforms/InstCombine/fold-phi-load-metadata.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fold-phi-load-metadata.ll?rev=248419&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fold-phi-load-metadata.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/fold-phi-load-metadata.ll Wed Sep 23 13:40:57 2015
@@ -0,0 +1,69 @@
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+ at g1 = common global i32* null, align 8
+
+%struct.S1 = type { i32, float }
+%struct.S2 = type { float, i32 }
+
+; Check that instcombine preserves metadata when it merges two loads.
+;
+; CHECK: return:
+; CHECK: load i32*, i32** %{{[a-z0-9.]+}}, align 8, !nonnull ![[EMPTYNODE:[0-9]+]]
+; CHECK: load i32, i32* %{{[a-z0-9.]+}}, align 4, !tbaa ![[TBAA:[0-9]+]], !range ![[RANGE:[0-9]+]], !invariant.load ![[EMPTYNODE:[0-9]+]], !alias.scope ![[ALIAS_SCOPE:[0-9]+]], !noalias ![[NOALIAS:[0-9]+]]
+
+; Function Attrs: nounwind ssp uwtable
+define i32 @phi_load_metadata(%struct.S1* %s1, %struct.S2* %s2, i32 %c, i32** %x0, i32 **%x1) #0 {
+entry:
+ %tobool = icmp eq i32 %c, 0
+ br i1 %tobool, label %if.end, label %if.then
+
+if.then: ; preds = %entry
+ %i = getelementptr inbounds %struct.S2, %struct.S2* %s2, i64 0, i32 1
+ %val = load i32, i32* %i, align 4, !tbaa !0, !alias.scope !13, !noalias !14, !invariant.load !17, !range !18
+ %p0 = load i32*, i32** %x0, align 8, !nonnull !17
+ br label %return
+
+if.end: ; preds = %entry
+ %i2 = getelementptr inbounds %struct.S1, %struct.S1* %s1, i64 0, i32 0
+ %val2 = load i32, i32* %i2, align 4, !tbaa !2, !alias.scope !15, !noalias !16, !invariant.load !17, !range !19
+ %p1 = load i32*, i32** %x1, align 8, !nonnull !17
+ br label %return
+
+return: ; preds = %if.end, %if.then
+ %retval = phi i32 [ %val, %if.then ], [ %val2, %if.end ]
+ %pval = phi i32* [ %p0, %if.then ], [ %p1, %if.end ]
+ store i32* %pval, i32** @g1, align 8
+ ret i32 %retval
+}
+
+; CHECK: ![[EMPTYNODE]] = !{}
+; CHECK: ![[TBAA]] = !{![[TAG1:[0-9]+]], ![[TAG1]], i64 0}
+; CHECK: ![[TAG1]] = !{!"int", !{{[0-9]+}}, i64 0}
+; CHECK: ![[RANGE]] = !{i32 10, i32 25}
+; CHECK: ![[ALIAS_SCOPE]] = !{![[SCOPE0:[0-9]+]], ![[SCOPE1:[0-9]+]], ![[SCOPE2:[0-9]+]]}
+; CHECK: ![[SCOPE0]] = distinct !{![[SCOPE0]], !{{[0-9]+}}, !"scope0"}
+; CHECK: ![[SCOPE1]] = distinct !{![[SCOPE1]], !{{[0-9]+}}, !"scope1"}
+; CHECK: ![[SCOPE2]] = distinct !{![[SCOPE2]], !{{[0-9]+}}, !"scope2"}
+; CHECK: ![[NOALIAS]] = !{![[SCOPE3:[0-9]+]]}
+; CHECK: ![[SCOPE3]] = distinct !{![[SCOPE3]], !{{[0-9]+}}, !"scope3"}
+
+!0 = !{!1, !4, i64 4}
+!1 = !{!"", !7, i64 0, !4, i64 4}
+!2 = !{!3, !4, i64 0}
+!3 = !{!"", !4, i64 0, !7, i64 4}
+!4 = !{!"int", !5, i64 0}
+!5 = !{!"omnipotent char", !6, i64 0}
+!6 = !{!"Simple C/C++ TBAA"}
+!7 = !{!"float", !5, i64 0}
+!8 = !{!8, !"some domain"}
+!9 = !{!9, !8, !"scope0"}
+!10 = !{!10, !8, !"scope1"}
+!11 = !{!11, !8, !"scope2"}
+!12 = !{!12, !8, !"scope3"}
+!13 = !{!9, !10}
+!14 = !{!11, !12}
+!15 = !{!9, !11}
+!16 = !{!10, !12}
+!17 = !{}
+!18 = !{i32 10, i32 20}
+!19 = !{i32 15, i32 25}
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