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| author | Vedant Kumar <vsk@apple.com> | 2018-02-15 22:26:18 +0000 |
|---|---|---|
| committer | Vedant Kumar <vsk@apple.com> | 2018-02-15 22:26:18 +0000 |
| commit | 1df820ecd722add744021dbdb59fa42828f8ca92 (patch) | |
| tree | 06689780ff3e0b2388fd815f5763be3e1ed2aa9f | |
| parent | 9967378eba5fcbbdb3bce4ce5c06af9fdea8f3d1 (diff) | |
| download | bcm5719-llvm-1df820ecd722add744021dbdb59fa42828f8ca92.tar.gz bcm5719-llvm-1df820ecd722add744021dbdb59fa42828f8ca92.zip | |
[DCE] Salvage debug info from dead insts
This results in small increases in the size of the .debug_loc section
and the number of unique source variables in a stage2 build of opt.
llvm-svn: 325301
| -rw-r--r-- | llvm/lib/Transforms/Scalar/DCE.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/DCE/basic.ll | 12 |
2 files changed, 11 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Scalar/DCE.cpp b/llvm/lib/Transforms/Scalar/DCE.cpp index fa4806e884c..d8575b71a3c 100644 --- a/llvm/lib/Transforms/Scalar/DCE.cpp +++ b/llvm/lib/Transforms/Scalar/DCE.cpp @@ -50,6 +50,7 @@ namespace { for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); ) { Instruction *Inst = &*DI++; if (isInstructionTriviallyDead(Inst, TLI)) { + salvageDebugInfo(*Inst); Inst->eraseFromParent(); Changed = true; ++DIEEliminated; @@ -76,6 +77,8 @@ static bool DCEInstruction(Instruction *I, SmallSetVector<Instruction *, 16> &WorkList, const TargetLibraryInfo *TLI) { if (isInstructionTriviallyDead(I, TLI)) { + salvageDebugInfo(*I); + // Null out all of the instruction's operands to see if any operand becomes // dead as we go. for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) { diff --git a/llvm/test/Transforms/DCE/basic.ll b/llvm/test/Transforms/DCE/basic.ll index c2a56594c91..6282ac78e75 100644 --- a/llvm/test/Transforms/DCE/basic.ll +++ b/llvm/test/Transforms/DCE/basic.ll @@ -1,11 +1,15 @@ -; RUN: opt -dce -S < %s | FileCheck %s -; RUN: opt -passes=dce -S < %s | FileCheck %s +; RUN: opt -debugify -dce -S < %s | FileCheck %s +; RUN: opt -passes='module(debugify),function(dce)' -S < %s | FileCheck %s ; CHECK-LABEL: @test define void @test() { -; CHECK-NOT: add %add = add i32 1, 2 -; CHECK-NOT: sub +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 1, metadata [[add:![0-9]+]], metadata !DIExpression(DW_OP_plus_uconst, 2, DW_OP_stack_value)) %sub = sub i32 %add, 1 +; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 1, metadata [[sub:![0-9]+]], metadata !DIExpression(DW_OP_plus_uconst, 2, DW_OP_constu, 1, DW_OP_minus, DW_OP_stack_value)) +; CHECK-NEXT: ret void ret void } + +; CHECK: [[add]] = !DILocalVariable +; CHECK: [[sub]] = !DILocalVariable |
