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-rw-r--r--include/llvm/Analysis/AliasAnalysis.h6
-rw-r--r--include/llvm/Analysis/MemoryDependenceAnalysis.h15
-rw-r--r--lib/Analysis/MemDepPrinter.cpp23
-rw-r--r--lib/Analysis/MemoryDependenceAnalysis.cpp47
-rw-r--r--lib/Transforms/Scalar/GVN.cpp6
-rw-r--r--test/Transforms/GVN/non-local-offset.ll59
6 files changed, 129 insertions, 27 deletions
diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index 17abae4eb9..302204e41b 100644
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -107,6 +107,12 @@ public:
return Copy;
}
+ Location getWithNewSize(uint64_t NewSize) const {
+ Location Copy(*this);
+ Copy.Size = NewSize;
+ return Copy;
+ }
+
Location getWithoutTBAATag() const {
Location Copy(*this);
Copy.TBAATag = 0;
diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h
index b5c68f6833..c1a1536037 100644
--- a/include/llvm/Analysis/MemoryDependenceAnalysis.h
+++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h
@@ -227,11 +227,14 @@ namespace llvm {
BBSkipFirstBlockPair Pair;
/// NonLocalDeps - The results of the query for each relevant block.
NonLocalDepInfo NonLocalDeps;
+ /// Size - The maximum size of the dereferences of the
+ /// pointer. May be UnknownSize if the sizes are unknown.
+ uint64_t Size;
/// TBAATag - The TBAA tag associated with dereferences of the
/// pointer. May be null if there are no tags or conflicting tags.
- MDNode *TBAATag;
+ const MDNode *TBAATag;
- NonLocalPointerInfo() : TBAATag(0) {}
+ NonLocalPointerInfo() : Size(0), TBAATag(0) {}
};
/// CachedNonLocalPointerInfo - This map stores the cached results of doing
@@ -315,14 +318,6 @@ namespace llvm {
bool isLoad, BasicBlock *BB,
SmallVectorImpl<NonLocalDepResult> &Result);
- /// getNonLocalPointerDependence - A convenience wrapper.
- void getNonLocalPointerDependency(Value *Pointer, bool isLoad,
- BasicBlock *BB,
- SmallVectorImpl<NonLocalDepResult> &Result){
- return getNonLocalPointerDependency(AliasAnalysis::Location(Pointer),
- isLoad, BB, Result);
- }
-
/// removeInstruction - Remove an instruction from the dependence analysis,
/// updating the dependence of instructions that previously depended on it.
void removeInstruction(Instruction *InstToRemove);
diff --git a/lib/Analysis/MemDepPrinter.cpp b/lib/Analysis/MemDepPrinter.cpp
index 597daff8db..90a7c576f0 100644
--- a/lib/Analysis/MemDepPrinter.cpp
+++ b/lib/Analysis/MemDepPrinter.cpp
@@ -11,6 +11,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/CallSite.h"
@@ -40,7 +41,8 @@ namespace {
void print(raw_ostream &OS, const Module * = 0) const;
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<MemoryDependenceAnalysis>();
+ AU.addRequiredTransitive<AliasAnalysis>();
+ AU.addRequiredTransitive<MemoryDependenceAnalysis>();
AU.setPreservesAll();
}
@@ -64,6 +66,7 @@ FunctionPass *llvm::createMemDepPrinter() {
bool MemDepPrinter::runOnFunction(Function &F) {
this->F = &F;
+ AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
MemoryDependenceAnalysis &MDA = getAnalysis<MemoryDependenceAnalysis>();
// All this code uses non-const interfaces because MemDep is not
@@ -99,15 +102,23 @@ bool MemDepPrinter::runOnFunction(Function &F) {
SmallVector<NonLocalDepResult, 4> NLDI;
if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
// FIXME: Volatile is not handled properly here.
- MDA.getNonLocalPointerDependency(LI->getPointerOperand(), !LI->isVolatile(),
+ AliasAnalysis::Location Loc(LI->getPointerOperand(),
+ AA.getTypeStoreSize(LI->getType()),
+ LI->getMetadata(LLVMContext::MD_tbaa));
+ MDA.getNonLocalPointerDependency(Loc, !LI->isVolatile(),
LI->getParent(), NLDI);
} else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
// FIXME: Volatile is not handled properly here.
- MDA.getNonLocalPointerDependency(SI->getPointerOperand(), false,
- SI->getParent(), NLDI);
+ AliasAnalysis::Location Loc(SI->getPointerOperand(),
+ AA.getTypeStoreSize(SI->getValueOperand()
+ ->getType()),
+ SI->getMetadata(LLVMContext::MD_tbaa));
+ MDA.getNonLocalPointerDependency(Loc, false, SI->getParent(), NLDI);
} else if (VAArgInst *VI = dyn_cast<VAArgInst>(Inst)) {
- MDA.getNonLocalPointerDependency(VI->getPointerOperand(), false,
- VI->getParent(), NLDI);
+ AliasAnalysis::Location Loc(SI->getPointerOperand(),
+ AliasAnalysis::UnknownSize,
+ SI->getMetadata(LLVMContext::MD_tbaa));
+ MDA.getNonLocalPointerDependency(Loc, false, VI->getParent(), NLDI);
} else {
llvm_unreachable("Unknown memory instruction!");
}
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index c72cd1e83a..b4c6d09e4c 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -741,16 +741,40 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
// Look up the cached info for Pointer.
ValueIsLoadPair CacheKey(Pointer.getAddr(), isLoad);
- NonLocalPointerInfo *CacheInfo = &NonLocalPointerDeps[CacheKey];
- // If this query's TBAATag is inconsistent with the cached one, discard the
- // tag and restart the query.
- if (CacheInfo->TBAATag != Loc.TBAATag) {
- CacheInfo->TBAATag = 0;
- NonLocalPointerDeps.erase(CacheKey);
- return getNonLocalPointerDepFromBB(Pointer, Loc.getWithoutTBAATag(),
- isLoad, StartBB, Result, Visited,
- SkipFirstBlock);
+ // Set up a temporary NLPI value. If the map doesn't yet have an entry for
+ // CacheKey, this value will be inserted as the associated value. Otherwise,
+ // it'll be ignored, and we'll have to check to see if the cached size and
+ // tbaa tag are consistent with the current query.
+ NonLocalPointerInfo InitialNLPI;
+ InitialNLPI.Size = Loc.Size;
+ InitialNLPI.TBAATag = Loc.TBAATag;
+
+ // Get the NLPI for CacheKey, inserting one into the map if it doesn't
+ // already have one.
+ std::pair<CachedNonLocalPointerInfo::iterator, bool> Pair =
+ NonLocalPointerDeps.insert(std::make_pair(CacheKey, InitialNLPI));
+ NonLocalPointerInfo *CacheInfo = &Pair.first->second;
+
+ if (!Pair.second) {
+ // If this query's Size is inconsistent with the cached one, take the
+ // maximum size and restart the query.
+ if (CacheInfo->Size != Loc.Size) {
+ CacheInfo->Size = std::max(CacheInfo->Size, Loc.Size);
+ return getNonLocalPointerDepFromBB(Pointer,
+ Loc.getWithNewSize(CacheInfo->Size),
+ isLoad, StartBB, Result, Visited,
+ SkipFirstBlock);
+ }
+
+ // If this query's TBAATag is inconsistent with the cached one, discard the
+ // tag and restart the query.
+ if (CacheInfo->TBAATag != Loc.TBAATag) {
+ CacheInfo->TBAATag = 0;
+ return getNonLocalPointerDepFromBB(Pointer, Loc.getWithoutTBAATag(),
+ isLoad, StartBB, Result, Visited,
+ SkipFirstBlock);
+ }
}
NonLocalDepInfo *Cache = &CacheInfo->NonLocalDeps;
@@ -796,6 +820,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
CacheInfo->Pair = BBSkipFirstBlockPair(StartBB, SkipFirstBlock);
else {
CacheInfo->Pair = BBSkipFirstBlockPair();
+ CacheInfo->Size = 0;
CacheInfo->TBAATag = 0;
}
@@ -921,6 +946,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
// cached value to do more work but not miss the phi trans failure.
NonLocalPointerInfo &NLPI = NonLocalPointerDeps[CacheKey];
NLPI.Pair = BBSkipFirstBlockPair();
+ NLPI.Size = 0;
NLPI.TBAATag = 0;
continue;
}
@@ -949,6 +975,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
// specific block queries) but we can't do the fastpath "return all
// results from the set" Clear out the indicator for this.
CacheInfo->Pair = BBSkipFirstBlockPair();
+ CacheInfo->Size = 0;
CacheInfo->TBAATag = 0;
SkipFirstBlock = false;
continue;
@@ -967,6 +994,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer,
// specific block queries) but we can't do the fastpath "return all
// results from the set". Clear out the indicator for this.
CacheInfo->Pair = BBSkipFirstBlockPair();
+ CacheInfo->Size = 0;
CacheInfo->TBAATag = 0;
// If *nothing* works, mark the pointer as being clobbered by the first
@@ -1184,6 +1212,7 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) {
// The cache is not valid for any specific block anymore.
NonLocalPointerDeps[P].Pair = BBSkipFirstBlockPair();
+ NonLocalPointerDeps[P].Size = 0;
NonLocalPointerDeps[P].TBAATag = 0;
// Update any entries for RemInst to use the instruction after it.
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index a2fcca5984..e506d0efd7 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1351,8 +1351,10 @@ bool GVN::processNonLocalLoad(LoadInst *LI,
SmallVectorImpl<Instruction*> &toErase) {
// Find the non-local dependencies of the load.
SmallVector<NonLocalDepResult, 64> Deps;
- MD->getNonLocalPointerDependency(LI->getPointerOperand(), true,
- LI->getParent(),
+ AliasAnalysis::Location Loc(LI->getPointerOperand(),
+ VN.getAliasAnalysis()->getTypeStoreSize(LI->getType()),
+ LI->getMetadata(LLVMContext::MD_tbaa));
+ MD->getNonLocalPointerDependency(Loc, true, LI->getParent(),
Deps);
//DEBUG(dbgs() << "INVESTIGATING NONLOCAL LOAD: "
// << Deps.size() << *LI << '\n');
diff --git a/test/Transforms/GVN/non-local-offset.ll b/test/Transforms/GVN/non-local-offset.ll
new file mode 100644
index 0000000000..8eaa99933a
--- /dev/null
+++ b/test/Transforms/GVN/non-local-offset.ll
@@ -0,0 +1,59 @@
+; RUN: opt -basicaa -gvn -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64"
+
+; GVN should ignore the store to p[1] to see that the load from p[0] is
+; fully redundant.
+
+; CHECK: @yes
+; CHECK: if.then:
+; CHECK-NEXT: store i32 0, i32* %q
+; CHECK-NEXT: ret void
+
+define void @yes(i1 %c, i32* %p, i32* %q) nounwind {
+entry:
+ store i32 0, i32* %p
+ %p1 = getelementptr inbounds i32* %p, i64 1
+ store i32 1, i32* %p1
+ br i1 %c, label %if.else, label %if.then
+
+if.then:
+ %t = load i32* %p
+ store i32 %t, i32* %q
+ ret void
+
+if.else:
+ ret void
+}
+
+; GVN should ignore the store to p[1] to see that the first load from p[0] is
+; fully redundant. However, the second load is larger, so it's not a simple
+; redundancy.
+
+; CHECK: @watch_out_for_size_change
+; CHECK: if.then:
+; CHECK-NEXT: store i32 0, i32* %q
+; CHECK-NEXT: ret void
+; CHECK: if.else:
+; CHECK: load i64* %pc
+; CHECK: store i64
+
+define void @watch_out_for_size_change(i1 %c, i32* %p, i32* %q) nounwind {
+entry:
+ store i32 0, i32* %p
+ %p1 = getelementptr inbounds i32* %p, i64 1
+ store i32 1, i32* %p1
+ br i1 %c, label %if.else, label %if.then
+
+if.then:
+ %t = load i32* %p
+ store i32 %t, i32* %q
+ ret void
+
+if.else:
+ %pc = bitcast i32* %p to i64*
+ %qc = bitcast i32* %q to i64*
+ %t64 = load i64* %pc
+ store i64 %t64, i64* %qc
+ ret void
+}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-05-01 16:56:19 +0000