llvm.org GIT mirror llvm / 38fa705
[BasicBlockUtils] Use getFirstNonPHIOrDbg to set debugloc for instructions created in SplitBlockPredecessors Summary: When setting debugloc for instructions created in SplitBlockPredecessors, current implementation copies debugloc from the first-non-phi instruction of the original basic block. However, if the first-non-phi instruction is a call for @llvm.dbg.value, the debugloc of the instruction may point the location outside of the block itself. For the example code of ``` 1 typedef struct _node_t { 2 struct _node_t *next; 3 } node_t; 4 5 extern node_t *root; 6 7 int foo() { 8 node_t *node, *tmp; 9 int ret = 0; 10 11 node = tmp = root->next; 12 while (node != root) { 13 while (node) { 14 tmp = node; 15 node = node->next; 16 ret++; 17 } 18 } 19 20 return ret; 21 } ``` , below is the basicblock corresponding to line 12 after Reassociate expressions pass: ``` while.cond: ; preds = %while.cond2, %entry %node.0 = phi %struct._node_t* [ %1, %entry ], [ null, %while.cond2 ] %ret.0 = phi i32 [ 0, %entry ], [ %ret.1, %while.cond2 ] tail call void @llvm.dbg.value(metadata i32 %ret.0, i64 0, metadata !19, metadata !20), !dbg !21 tail call void @llvm.dbg.value(metadata %struct._node_t* %node.0, i64 0, metadata !11, metadata !20), !dbg !31 %cmp = icmp eq %struct._node_t* %node.0, %0, !dbg !33 br i1 %cmp, label %while.end5, label %while.cond2, !dbg !35 ``` As you can see, the first-non-phi instruction is a call for @llvm.dbg.value, and the debugloc is ``` !21 = !DILocation(line: 9, column: 7, scope: !6) ``` , which is a definition of 'ret' variable and outside of the scope of the basicblock itself. However, current implementation picks up this debugloc for the instructions created in SplitBlockPredecessors. This patch addresses this problem by picking up debugloc from the first-non-phi-non-dbg instruction. Reviewers: dblaikie, samsonov, eugenis Reviewed By: eugenis Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D29867 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295106 91177308-0d34-0410-b5e6-96231b3b80d8 Taewook Oh 2 years ago
2 changed file(s) with 8 addition(s) and 1 deletion(s). Raw diff Collapse all Expand all
437437
438438 // The new block unconditionally branches to the old block.
439439 BranchInst *BI = BranchInst::Create(BB, NewBB);
440 BI->setDebugLoc(BB->getFirstNonPHI()->getDebugLoc());
440 BI->setDebugLoc(BB->getFirstNonPHIOrDbg()->getDebugLoc());
441441
442442 // Move the edges from Preds to point to NewBB instead of BB.
443443 for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
2222
2323 for.body: ; preds = %entry, %length.exit
2424 %begin.sink5 = phi %"Length"* [ %incdec.ptr, %length.exit ], [ %begin, %entry ]
25 tail call void @llvm.dbg.value(metadata %"Length"* %begin.sink5, i64 0, metadata !15, metadata !16), !dbg !17
2526 %m_type.i.i.i = getelementptr inbounds %"Length", %"Length"* %begin.sink5, i64 0, i32 2, !dbg !9
2627 %0 = load i8, i8* %m_type.i.i.i, align 1, !dbg !9
2728 %cmp.i.i = icmp eq i8 %0, 9, !dbg !7
6768 resume { i8*, i32 } undef, !dbg !13
6869 }
6970
71 ; Function Attrs: nounwind readnone
72 declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
73
7074 ; CHECK-DAG: [[PREHEADER_LOC]] = !DILocation(line: 73, column: 27, scope: !{{[0-9]+}})
7175 ; CHECK-DAG: [[LOOPEXIT_LOC]] = !DILocation(line: 75, column: 9, scope: !{{[0-9]+}})
7276 ; CHECK-DAG: [[LPAD_PREHEADER_LOC]] = !DILocation(line: 85, column: 1, scope: !{{[0-9]+}})
9296 file: !5,
9397 isOptimized: true, flags: "-O2",
9498 splitDebugFilename: "abc.debug", emissionKind: 2)
99 !15 = !DILocalVariable(name: "begin", arg: 1, scope: !6, file: !5, line: 71)
100 !16 = !DIExpression()
101 !17 = !DILocation(line: 71, column: 32, scope: !6)