diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineInternal.h | 4 | ||||
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp | 18 | ||||
| -rw-r--r-- | llvm/test/DebugInfo/Generic/instcombine-phi.ll | 70 |
3 files changed, 91 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h index e6b9bca1289..d13b94cb6c9 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h +++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h @@ -553,6 +553,10 @@ private: Instruction *FoldPHIArgLoadIntoPHI(PHINode &PN); Instruction *FoldPHIArgZextsIntoPHI(PHINode &PN); + /// Helper function for FoldPHIArgXIntoPHI() to get debug location for the + /// folded operation. + DebugLoc PHIArgMergedDebugLoc(PHINode &PN); + Instruction *foldGEPICmp(GEPOperator *GEPLHS, Value *RHS, ICmpInst::Predicate Cond, Instruction &I); Instruction *foldAllocaCmp(ICmpInst &ICI, const AllocaInst *Alloca, diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp index 675a5d17ad9..91bfe6c5c82 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp @@ -18,11 +18,27 @@ #include "llvm/Analysis/ValueTracking.h" #include "llvm/IR/PatternMatch.h" #include "llvm/Transforms/Utils/Local.h" +#include "llvm/IR/DebugInfo.h" using namespace llvm; using namespace llvm::PatternMatch; #define DEBUG_TYPE "instcombine" +/// The PHI arguments will be folded into a single operation with a PHI node +/// as input. The debug location of the single operation will be the merged +/// locations of the original PHI node arguments. +DebugLoc InstCombiner::PHIArgMergedDebugLoc(PHINode &PN) { + auto *FirstInst = cast<Instruction>(PN.getIncomingValue(0)); + DILocation *Loc = FirstInst->getDebugLoc(); + + for (unsigned i = 1; i != PN.getNumIncomingValues(); ++i) { + auto *I = cast<Instruction>(PN.getIncomingValue(i)); + Loc = DILocation::getMergedLocation(Loc, I->getDebugLoc()); + } + + return Loc; +} + /// If we have something like phi [add (a,b), add(a,c)] and if a/b/c and the /// adds all have a single use, turn this into a phi and a single binop. Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { @@ -114,7 +130,7 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) NewBinOp->andIRFlags(PN.getIncomingValue(i)); - NewBinOp->setDebugLoc(FirstInst->getDebugLoc()); + NewBinOp->setDebugLoc(PHIArgMergedDebugLoc(PN)); return NewBinOp; } diff --git a/llvm/test/DebugInfo/Generic/instcombine-phi.ll b/llvm/test/DebugInfo/Generic/instcombine-phi.ll new file mode 100644 index 00000000000..8d8e1cd3c06 --- /dev/null +++ b/llvm/test/DebugInfo/Generic/instcombine-phi.ll @@ -0,0 +1,70 @@ +; RUN: opt -instcombine -S < %s | FileCheck %s + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +; If all the operands to a phi node are of the same operation, instcombine +; will try to pull them through the phi node, combining them into a single +; operation. Check that when it does this the combined operation does not +; have a debug location set. + +; Test folding of a binary operation. Generated from source: + +; extern int foo(void); +; extern int bar(void); +; +; int binop(int a, int b) { +; if(a) +; b -= foo(); +; else +; b -= bar(); +; return b; +; } + +; CHECK: define i32 @binop +; CHECK-LABEL: if.end: +; CHECK: %[[PHI:.*]] = phi i32 [ %call, %if.then ], [ %call1, %if.else ] +; CHECK: sub nsw i32 %b, %[[PHI]] +; CHECK-NOT: !dbg +; CHECK: ret i32 + +define i32 @binop(i32 %a, i32 %b) !dbg !6 { +entry: + %tobool = icmp ne i32 %a, 0, !dbg !8 + br i1 %tobool, label %if.then, label %if.else, !dbg !8 + +if.then: ; preds = %entry + %call = call i32 @foo(), !dbg !9 + %sub = sub nsw i32 %b, %call, !dbg !10 + br label %if.end, !dbg !11 + +if.else: ; preds = %entry + %call1 = call i32 @bar(), !dbg !12 + %sub2 = sub nsw i32 %b, %call1, !dbg !13 + br label %if.end + +if.end: ; preds = %if.else, %if.then + %b.addr.0 = phi i32 [ %sub, %if.then ], [ %sub2, %if.else ] + ret i32 %b.addr.0, !dbg !14 +} + +declare i32 @foo() +declare i32 @bar() + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "", isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2) +!1 = !DIFile(filename: "test.c", directory: "") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!6 = distinct !DISubprogram(name: "binop", scope: !1, file: !1, line: 8, type: !7, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2) +!7 = !DISubroutineType(types: !2) +!8 = !DILocation(line: 9, column: 6, scope: !6) +!9 = !DILocation(line: 10, column: 10, scope: !6) +!10 = !DILocation(line: 10, column: 7, scope: !6) +!11 = !DILocation(line: 10, column: 5, scope: !6) +!12 = !DILocation(line: 12, column: 10, scope: !6) +!13 = !DILocation(line: 12, column: 7, scope: !6) +!14 = !DILocation(line: 13, column: 3, scope: !6) |
