diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1626,17 +1626,23 @@
// Check for any extra throws between SI and NI that block DSE. This only
// checks extra maythrows (those that arn't MemoryDef's). MemoryDef that may
// throw are handled during the walk from one def to the next.
-bool mayThrowBetween(Instruction *SI, Instruction *NI, const Value *SILocUnd,
- SmallSetVector<const Value *, 16> &InvisibleToCaller,
- SmallPtrSetImpl<BasicBlock *> &ThrowingBlocks) {
+bool mayThrowBetween(
+ Instruction *SI, Instruction *NI, const Value *SILocUnd,
+ SmallSetVector<const Value *, 16> &InvisibleToCaller,
+ DenseMap<BasicBlock *, DenseMap<Instruction *, unsigned>> &ThrowingBlocks) {
// First see if we can ignore it by using the fact that SI is an alloca/alloca
// like object that is not visible to the caller during execution of the
// function.
if (SILocUnd && InvisibleToCaller.count(SILocUnd))
return false;
- if (SI->getParent() == NI->getParent())
- return ThrowingBlocks.find(SI->getParent()) != ThrowingBlocks.end();
+ if (SI->getParent() == NI->getParent()) {
+ auto BlockMap = ThrowingBlocks.find(SI->getParent());
+ if (BlockMap == ThrowingBlocks.end())
+ return false;
+ return BlockMap->second[SI] !=
+ BlockMap->second[&*std::prev(NI->getIterator())];
+ }
return !ThrowingBlocks.empty();
}
@@ -1692,8 +1698,12 @@
// Keep track of all of the objects that are invisible to the caller until the
// function returns.
SmallSetVector<const Value *, 16> InvisibleToCaller;
- // Keep track of blocks with throwing instructions.
- SmallPtrSet<BasicBlock *, 16> ThrowingBlocks;
+ // Keep track of blocks with throwing instructions. For each block with
+ // throwing instructions, we number all instructions in the block, starting
+ // with 0 and incrementing the counter for throwing instructions. If 2
+ // instructions have the same number there are no throwing instructions
+ // between them.
+ DenseMap<BasicBlock *, DenseMap<Instruction *, unsigned>> ThrowingBlocks;
// Post-order numbers for basic blocks in the function.
DenseMap<BasicBlock *, unsigned> PostOrderNumbers;
@@ -1702,9 +1712,13 @@
// post-order numbers for basic blocks.
for (BasicBlock *BB : post_order(&F)) {
PostOrderNumbers[BB] = PO++;
+
+ unsigned ThrowingCnt = 0;
+ DenseMap<Instruction *, unsigned> BlockMap;
for (Instruction &I : *BB) {
if (I.mayThrow())
- ThrowingBlocks.insert(I.getParent());
+ ThrowingCnt++;
+ BlockMap[&I] = ThrowingCnt;
auto *MD = dyn_cast_or_null<MemoryDef>(MSSA.getMemoryAccess(&I));
if (MD && hasAnalyzableMemoryWrite(&I, TLI) && isRemovable(&I))
@@ -1718,6 +1732,10 @@
(isAllocLikeFn(&I, &TLI) && !PointerMayBeCaptured(&I, false, true)))
InvisibleToCaller.insert(&I);
}
+
+ // Only add the mapping for blocks with any throwing instructions.
+ if (ThrowingCnt != 0)
+ ThrowingBlocks[BB] = BlockMap;
}
// Treat byval or inalloca arguments the same as Allocas, stores to them are
// dead at the end of the function.
diff --git a/llvm/test/Transforms/DeadStoreElimination/MSSA/combined-partial-overwrites.ll b/llvm/test/Transforms/DeadStoreElimination/MSSA/combined-partial-overwrites.ll
--- a/llvm/test/Transforms/DeadStoreElimination/MSSA/combined-partial-overwrites.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/MSSA/combined-partial-overwrites.ll
@@ -1,5 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -dse -enable-dse-partial-store-merging=false < %s | FileCheck %s
+; RUN: opt -S -dse -enable-dse-memoryssa -enable-dse-partial-store-merging=false < %s | FileCheck %s
target datalayout = "E-m:e-i64:64-n32:64"
target triple = "powerpc64-bgq-linux"
@@ -252,6 +252,7 @@
; CHECK-NEXT: [[BPTR:%.*]] = bitcast i32* [[PTR:%.*]] to i8*
; CHECK-NEXT: [[BPTR1:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 1
; CHECK-NEXT: [[BPTR2:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 2
+; CHECK-NEXT: [[BPTR3:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 3
; CHECK-NEXT: [[WPTR:%.*]] = bitcast i8* [[BPTR]] to i16*
; CHECK-NEXT: [[WPTR1:%.*]] = bitcast i8* [[BPTR1]] to i16*
; CHECK-NEXT: [[WPTR2:%.*]] = bitcast i8* [[BPTR2]] to i16*
diff --git a/llvm/test/Transforms/DeadStoreElimination/MSSA/simple.ll b/llvm/test/Transforms/DeadStoreElimination/MSSA/simple.ll
--- a/llvm/test/Transforms/DeadStoreElimination/MSSA/simple.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/MSSA/simple.ll
@@ -218,7 +218,7 @@
; it could unwind
define void @test34(i32* noalias %p) {
; CHECK-LABEL: @test34(
-; CHECK-NEXT: store i32 1, i32* [[P]]
+; CHECK-NEXT: store i32 1, i32* [[P:%.*]]
; CHECK-NEXT: call void @unknown_func()
; CHECK-NEXT: store i32 0, i32* [[P]]
; CHECK-NEXT: ret void
@@ -229,12 +229,10 @@
ret void
}
-; TODO
; Remove redundant store even with an unwinding function in the same block
define void @test35(i32* noalias %p) {
; CHECK-LABEL: @test35(
; CHECK-NEXT: call void @unknown_func()
-; CHECK-NEXT: store i32 1, i32* [[P:%.*]]
; CHECK-NEXT: store i32 0, i32* [[P:%.*]]
; CHECK-NEXT: ret void
;
@@ -384,6 +382,14 @@
; NOCHECK-NEXT: call void @unknown_func()
; NOCHECK-NEXT: call void @free(i8* [[P2]])
; NOCHECK-NEXT: ret void
+;
+; CHECK-LABEL: @test41(
+; CHECK-NEXT: [[P2:%.*]] = bitcast i32* [[P:%.*]] to i8*
+; CHECK-NEXT: store i32 1, i32* [[P]]
+; CHECK-NEXT: call void @unknown_func()
+; CHECK-NEXT: store i32 2, i32* [[P]]
+; CHECK-NEXT: call void @free(i8* [[P2]])
+; CHECK-NEXT: ret void
;
%P2 = bitcast i32* %P to i8*
store i32 1, i32* %P
@@ -400,6 +406,13 @@
; NOCHECK-NEXT: store i32 2, i32* [[Q:%.*]]
; NOCHECK-NEXT: store i8 3, i8* [[P2]]
; NOCHECK-NEXT: ret void
+;
+; CHECK-LABEL: @test42(
+; CHECK-NEXT: store i32 1, i32* [[P:%.*]]
+; CHECK-NEXT: [[P2:%.*]] = bitcast i32* [[P]] to i8*
+; CHECK-NEXT: store i32 2, i32* [[Q:%.*]]
+; CHECK-NEXT: store i8 3, i8* [[P2]]
+; CHECK-NEXT: ret void
;
store i32 1, i32* %P
%P2 = bitcast i32* %P to i8*
@@ -415,6 +428,13 @@
; NOCHECK-NEXT: store atomic i32 2, i32* [[Q:%.*]] unordered, align 4
; NOCHECK-NEXT: store atomic i8 3, i8* [[P2]] unordered, align 4
; NOCHECK-NEXT: ret void
+;
+; CHECK-LABEL: @test42a(
+; CHECK-NEXT: store atomic i32 1, i32* [[P:%.*]] unordered, align 4
+; CHECK-NEXT: [[P2:%.*]] = bitcast i32* [[P]] to i8*
+; CHECK-NEXT: store atomic i32 2, i32* [[Q:%.*]] unordered, align 4
+; CHECK-NEXT: store atomic i8 3, i8* [[P2]] unordered, align 4
+; CHECK-NEXT: ret void
;
store atomic i32 1, i32* %P unordered, align 4
%P2 = bitcast i32* %P to i8*