diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/GVN.cpp | 14 | ||||
| -rw-r--r-- | llvm/test/Transforms/GVN/PRE/phi-translate.ll | 13 |
2 files changed, 18 insertions, 9 deletions
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp index 9485bfd7c29..0137378b828 100644 --- a/llvm/lib/Transforms/Scalar/GVN.cpp +++ b/llvm/lib/Transforms/Scalar/GVN.cpp @@ -1572,6 +1572,13 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, // Assign value numbers to the new instructions. for (Instruction *I : NewInsts) { + // Instructions that have been inserted in predecessor(s) to materialize + // the load address do not retain their original debug locations. Doing + // so could lead to confusing (but correct) source attributions. + // FIXME: How do we retain source locations without causing poor debugging + // behavior? + I->setDebugLoc(DebugLoc()); + // FIXME: We really _ought_ to insert these value numbers into their // parent's availability map. However, in doing so, we risk getting into // ordering issues. If a block hasn't been processed yet, we would be @@ -1601,8 +1608,11 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, if (auto *RangeMD = LI->getMetadata(LLVMContext::MD_range)) NewLoad->setMetadata(LLVMContext::MD_range, RangeMD); - // Transfer DebugLoc. - NewLoad->setDebugLoc(LI->getDebugLoc()); + // We do not propagate the old load's debug location, because the new + // load now lives in a different BB, and we want to avoid a jumpy line + // table. + // FIXME: How do we retain source locations without causing poor debugging + // behavior? // Add the newly created load. ValuesPerBlock.push_back(AvailableValueInBlock::get(UnavailablePred, diff --git a/llvm/test/Transforms/GVN/PRE/phi-translate.ll b/llvm/test/Transforms/GVN/PRE/phi-translate.ll index 42335486910..1f6c7c8d33e 100644 --- a/llvm/test/Transforms/GVN/PRE/phi-translate.ll +++ b/llvm/test/Transforms/GVN/PRE/phi-translate.ll @@ -4,18 +4,17 @@ target datalayout = "e-p:64:64:64" ; CHECK-LABEL: @foo( ; CHECK: entry.end_crit_edge: -; CHECK: %j.phi.trans.insert = sext i32 %x to i64, !dbg [[J_LOC:![0-9]+]] -; CHECK: %q.phi.trans.insert = getelementptr {{.*}}, !dbg [[Q_LOC:![0-9]+]] -; CHECK: %n.pre = load i32, i32* %q.phi.trans.insert, !dbg [[N_LOC:![0-9]+]] +; CHECK: %[[INDEX:[a-z0-9.]+]] = sext i32 %x to i64{{$}} +; CHECK: %[[ADDRESS:[a-z0-9.]+]] = getelementptr [100 x i32], [100 x i32]* @G, i64 0, i64 %[[INDEX]]{{$}} +; CHECK: %n.pre = load i32, i32* %[[ADDRESS]]{{$}} +; CHECK: br label %end ; CHECK: then: ; CHECK: store i32 %z ; CHECK: end: -; CHECK: %n = phi i32 [ %n.pre, %entry.end_crit_edge ], [ %z, %then ], !dbg [[N_LOC]] +; CHECK: %n = phi i32 [ %n.pre, %entry.end_crit_edge ], [ %z, %then ], !dbg [[N_LOC:![0-9]+]] ; CHECK: ret i32 %n -; CHECK-DAG: [[J_LOC]] = !DILocation(line: 45, column: 1, scope: !{{.*}}) -; CHECK-DAG: [[Q_LOC]] = !DILocation(line: 46, column: 1, scope: !{{.*}}) -; CHECK-DAG: [[N_LOC]] = !DILocation(line: 47, column: 1, scope: !{{.*}}) +; CHECK: [[N_LOC]] = !DILocation(line: 47, column: 1, scope: !{{.*}}) @G = external global [100 x i32] define i32 @foo(i32 %x, i32 %z) !dbg !6 { |
