diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/MergeICmps.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/Transforms/MergeICmps/X86/two-complex-bb.ll | 58 |
2 files changed, 62 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Scalar/MergeICmps.cpp b/llvm/lib/Transforms/Scalar/MergeICmps.cpp index f045b62a922..745d29d14dd 100644 --- a/llvm/lib/Transforms/Scalar/MergeICmps.cpp +++ b/llvm/lib/Transforms/Scalar/MergeICmps.cpp @@ -278,7 +278,8 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi) assert(!Blocks.empty() && "a chain should have at least one block"); // Now look inside blocks to check for BCE comparisons. std::vector<BCECmpBlock> Comparisons; - for (BasicBlock *Block : Blocks) { + for (size_t BlockIdx = 0; BlockIdx < Blocks.size(); ++BlockIdx) { + BasicBlock *const Block = Blocks[BlockIdx]; assert(Block && "invalid block"); BCECmpBlock Comparison = visitCmpBlock(Phi.getIncomingValueForBlock(Block), Block, Phi.getParent()); @@ -289,7 +290,7 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi) } if (Comparison.doesOtherWork()) { DEBUG(dbgs() << "block does extra work besides compare\n"); - if (Comparisons.empty()) { // First block. + if (BlockIdx == 0) { // First block. // TODO(courbet): The first block can do other things, and we should // split them apart in a separate block before the comparison chain. // Right now we just discard it and make the chain shorter. @@ -330,7 +331,7 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi) DEBUG(dbgs() << "\n"); Comparisons.push_back(Comparison); } - assert(!Comparisons.empty() && "chain with a single complex basic block"); + assert(!Comparisons.empty() && "chain with no BCE basic blocks"); EntryBlock_ = Comparisons[0].BB; Comparisons_ = std::move(Comparisons); #ifdef MERGEICMPS_DOT_ON diff --git a/llvm/test/Transforms/MergeICmps/X86/two-complex-bb.ll b/llvm/test/Transforms/MergeICmps/X86/two-complex-bb.ll new file mode 100644 index 00000000000..945a2d076f6 --- /dev/null +++ b/llvm/test/Transforms/MergeICmps/X86/two-complex-bb.ll @@ -0,0 +1,58 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -mergeicmps -mtriple=x86_64-unknown-unknown -S | FileCheck %s --check-prefix=X86 + +%"struct.std::pair" = type { i32, i32 } + +; This tests a function with two complex basic blocks. +define zeroext i1 @twocomplexblocks( +; X86-LABEL: @twocomplexblocks( +; X86-NEXT: entry: +; X86-NEXT: [[FIRST_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[A:%.*]], i64 0, i32 0 +; X86-NEXT: [[TMP0:%.*]] = load i32, i32* [[FIRST_I]], align 4 +; X86-NEXT: [[FIRST1_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[B:%.*]], i64 0, i32 0 +; X86-NEXT: [[TMP1:%.*]] = load i32, i32* [[FIRST1_I]], align 4 +; X86-NEXT: [[EXTRAWORK:%.*]] = add i32 [[TMP0]], [[TMP1]] +; X86-NEXT: [[CMP_I:%.*]] = icmp eq i32 [[TMP0]], [[TMP1]] +; X86-NEXT: br i1 [[CMP_I]], label [[LAND_RHS_I:%.*]], label [[OPEQ1_EXIT:%.*]] +; X86: land.rhs.i: +; X86-NEXT: [[SECOND_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[A]], i64 0, i32 1 +; X86-NEXT: [[TMP2:%.*]] = load i32, i32* [[SECOND_I]], align 4 +; X86-NEXT: [[SECOND2_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[B]], i64 0, i32 1 +; X86-NEXT: [[TMP3:%.*]] = load i32, i32* [[SECOND2_I]], align 4 +; X86-NEXT: [[EXTRAWORK2:%.*]] = add i32 [[TMP2]], [[TMP3]] +; X86-NEXT: [[CMP3_I:%.*]] = icmp eq i32 [[TMP2]], [[TMP3]] +; X86-NEXT: br label [[OPEQ1_EXIT]] +; X86: opeq1.exit: +; X86-NEXT: [[TMP4:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[CMP3_I]], [[LAND_RHS_I]] ] +; X86-NEXT: ret i1 [[TMP4]] +; + %"struct.std::pair"* nocapture readonly dereferenceable(8) %a, + %"struct.std::pair"* nocapture readonly dereferenceable(8) %b) local_unnamed_addr #0 { +entry: + ; This is a complex BCE Basic Block. + %first.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 0 + %0 = load i32, i32* %first.i, align 4 + %first1.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 0 + %1 = load i32, i32* %first1.i, align 4 + %extrawork = add i32 %0, %1 + %cmp.i = icmp eq i32 %0, %1 + br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit + +land.rhs.i: + ; This is a complex BCE Basic Block. + %second.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 1 + %2 = load i32, i32* %second.i, align 4 + %second2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 1 + %3 = load i32, i32* %second2.i, align 4 + %extrawork2 = add i32 %2, %3 + %cmp3.i = icmp eq i32 %2, %3 + br label %opeq1.exit + +opeq1.exit: + %4 = phi i1 [ false, %entry ], [ %cmp3.i, %land.rhs.i ] + ret i1 %4 +} + + + + |
