diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/pr44552.ll | 59 |
2 files changed, 64 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index ebf9d24eecc..c288a7d8d40 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -1439,9 +1439,12 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { if (PrevSI->isUnordered() && equivalentAddressValues(PrevSI->getOperand(1), SI.getOperand(1))) { ++NumDeadStore; - ++BBI; + // Manually add back the original store to the worklist now, so it will + // be processed after the operands of the removed store, as this may + // expose additional DSE opportunities. + Worklist.Add(&SI); eraseInstFromFunction(*PrevSI); - continue; + return nullptr; } break; } diff --git a/llvm/test/Transforms/InstCombine/pr44552.ll b/llvm/test/Transforms/InstCombine/pr44552.ll new file mode 100644 index 00000000000..adefe829df2 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/pr44552.ll @@ -0,0 +1,59 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -S -instcombine -instcombine-infinite-loop-threshold=2 < %s | FileCheck %s + +; This used to require 10 instcombine iterations to fully optimize. +; The number of iterations grew linearly with the number of DSEd stores, +; resulting in overall quadratic runtime. + +%struct.S3 = type { i64 } + +@csmith_sink_ = dso_local global i64 0, align 1 +@g_302_7 = internal constant i32 0, align 1 +@g_313_0 = internal global i16 0, align 1 +@g_313_1 = internal global i32 0, align 1 +@g_313_2 = internal global i32 0, align 1 +@g_313_3 = internal global i32 0, align 1 +@g_313_4 = internal global i16 0, align 1 +@g_313_5 = internal global i16 0, align 1 +@g_313_6 = internal global i16 0, align 1 +@g_316 = internal global %struct.S3 zeroinitializer, align 1 +@g_316_1_0 = internal global i16 0, align 1 + +define i16 @main() { +; CHECK-LABEL: @main( +; CHECK-NEXT: entry: +; CHECK-NEXT: store i64 0, i64* @csmith_sink_, align 8 +; CHECK-NEXT: ret i16 0 +; +entry: + store i64 0, i64* @csmith_sink_, align 1 + %0 = load i16, i16* @g_313_0, align 1 + %conv2 = sext i16 %0 to i64 + store i64 %conv2, i64* @csmith_sink_, align 1 + %1 = load i32, i32* @g_313_1, align 1 + %conv3 = zext i32 %1 to i64 + store i64 %conv3, i64* @csmith_sink_, align 1 + %2 = load i32, i32* @g_313_2, align 1 + %conv4 = sext i32 %2 to i64 + store i64 %conv4, i64* @csmith_sink_, align 1 + %3 = load i32, i32* @g_313_3, align 1 + %conv5 = zext i32 %3 to i64 + store i64 %conv5, i64* @csmith_sink_, align 1 + %4 = load i16, i16* @g_313_4, align 1 + %conv6 = sext i16 %4 to i64 + store i64 %conv6, i64* @csmith_sink_, align 1 + %5 = load i16, i16* @g_313_5, align 1 + %conv7 = sext i16 %5 to i64 + store i64 %conv7, i64* @csmith_sink_, align 1 + %6 = load i16, i16* @g_313_6, align 1 + %conv8 = sext i16 %6 to i64 + store i64 %conv8, i64* @csmith_sink_, align 1 + %7 = load i64, i64* getelementptr inbounds (%struct.S3, %struct.S3* @g_316, i32 0, i32 0), align 1 + store i64 %7, i64* @csmith_sink_, align 1 + %8 = load i16, i16* @g_316_1_0, align 1 + %conv9 = sext i16 %8 to i64 + store i64 %conv9, i64* @csmith_sink_, align 1 + store i64 0, i64* @csmith_sink_, align 1 + ret i16 0 +} + |
