[llvm] r293372 - [InstCombine] Merge DebugLoc when speculatively hoisting store instruction
Taewook Oh via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 27 23:05:43 PST 2017
Author: twoh
Date: Sat Jan 28 01:05:43 2017
New Revision: 293372
URL: http://llvm.org/viewvc/llvm-project?rev=293372&view=rev
Log:
[InstCombine] Merge DebugLoc when speculatively hoisting store instruction
Summary: Along with https://reviews.llvm.org/D27804, debug locations need to be merged when hoisting store instructions as well. Not sure if just dropping debug locations would make more sense for this case, but as the branch instruction will have at least different discriminator with the hoisted store instruction, I think there will be no difference in practice.
Reviewers: aprantl, andreadb, danielcdh
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29062
Added:
llvm/trunk/test/Transforms/SimplifyCFG/remove-debug-2.ll
Modified:
llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=293372&r1=293371&r2=293372&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Sat Jan 28 01:05:43 2017
@@ -1280,7 +1280,7 @@ static bool HoistThenElseCodeToIf(Branch
if (!isa<CallInst>(I1))
I1->setDebugLoc(
DILocation::getMergedLocation(I1->getDebugLoc(), I2->getDebugLoc()));
-
+
I2->eraseFromParent();
Changed = true;
@@ -1546,7 +1546,7 @@ static bool sinkLastInstruction(ArrayRef
}))
return false;
}
-
+
// We don't need to do any more checking here; canSinkLastInstruction should
// have done it all for us.
SmallVector<Value*, 4> NewOperands;
@@ -1653,7 +1653,7 @@ namespace {
bool isValid() const {
return !Fail;
}
-
+
void operator -- () {
if (Fail)
return;
@@ -1737,7 +1737,7 @@ static bool SinkThenElseCodeToEnd(Branch
}
if (UnconditionalPreds.size() < 2)
return false;
-
+
bool Changed = false;
// We take a two-step approach to tail sinking. First we scan from the end of
// each block upwards in lockstep. If the n'th instruction from the end of each
@@ -1767,7 +1767,7 @@ static bool SinkThenElseCodeToEnd(Branch
unsigned NumPHIInsts = NumPHIdValues / UnconditionalPreds.size();
if ((NumPHIdValues % UnconditionalPreds.size()) != 0)
NumPHIInsts++;
-
+
return NumPHIInsts <= 1;
};
@@ -1790,7 +1790,7 @@ static bool SinkThenElseCodeToEnd(Branch
}
if (!Profitable)
return false;
-
+
DEBUG(dbgs() << "SINK: Splitting edge\n");
// We have a conditional edge and we're going to sink some instructions.
// Insert a new block postdominating all blocks we're going to sink from.
@@ -1800,7 +1800,7 @@ static bool SinkThenElseCodeToEnd(Branch
return false;
Changed = true;
}
-
+
// Now that we've analyzed all potential sinking candidates, perform the
// actual sink. We iteratively sink the last non-terminator of the source
// blocks into their common successor unless doing so would require too
@@ -1826,7 +1826,7 @@ static bool SinkThenElseCodeToEnd(Branch
DEBUG(dbgs() << "SINK: stopping here, too many PHIs would be created!\n");
break;
}
-
+
if (!sinkLastInstruction(UnconditionalPreds))
return Changed;
NumSinkCommons++;
@@ -2078,6 +2078,9 @@ static bool SpeculativelyExecuteBB(Branc
Value *S = Builder.CreateSelect(
BrCond, TrueV, FalseV, TrueV->getName() + "." + FalseV->getName(), BI);
SpeculatedStore->setOperand(0, S);
+ SpeculatedStore->setDebugLoc(
+ DILocation::getMergedLocation(
+ BI->getDebugLoc(), SpeculatedStore->getDebugLoc()));
}
// Metadata can be dependent on the condition we are hoisting above.
Added: llvm/trunk/test/Transforms/SimplifyCFG/remove-debug-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/remove-debug-2.ll?rev=293372&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/remove-debug-2.ll (added)
+++ llvm/trunk/test/Transforms/SimplifyCFG/remove-debug-2.ll Sat Jan 28 01:05:43 2017
@@ -0,0 +1,68 @@
+; RUN: opt < %s -simplifycfg -S | FileCheck %s
+
+; Check if the debug info for hoisted store for "ret = 0" is removed
+;
+; int foo(int x) {
+; int ret = 1;
+; if (x)
+; ret = 0;
+; return ret;
+; }
+;
+; CHECK: store i32 1,{{.+}}!dbg ![[DLOC1:[0-9]+]]
+; CHECK: icmp ne {{.+}}!dbg ![[DLOC2:[0-9]+]]
+; CHECK: [[VREG:%[^ ]+]] = select
+; CHECK: store i32 [[VREG]]
+; CHECK-NOT: !dbg
+; CHECK-SAME: {{$}}
+; CHECK: ret {{.+}}!dbg ![[DLOC3:[0-9]+]]
+; CHECK: ![[DLOC1]] = !DILocation(line: 2
+; CHECK: ![[DLOC2]] = !DILocation(line: 3
+; CHECK: ![[DLOC3]] = !DILocation(line: 5
+
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline nounwind uwtable
+define i32 @foo(i32) !dbg !6 {
+ %2 = alloca i32, align 4
+ %3 = alloca i32, align 4
+ store i32 %0, i32* %2, align 4
+ store i32 1, i32* %3, align 4, !dbg !14
+ %4 = load i32, i32* %2, align 4, !dbg !15
+ %5 = icmp ne i32 %4, 0, !dbg !15
+ br i1 %5, label %6, label %7, !dbg !17
+
+; <label>:6: ; preds = %1
+ store i32 0, i32* %3, align 4, !dbg !18
+ br label %7, !dbg !19
+
+; <label>:7: ; preds = %6, %1
+ %8 = load i32, i32* %3, align 4, !dbg !20
+ ret i32 %8, !dbg !21
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1)
+!1 = !DIFile(filename: "foo.c", directory: "b/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{}
+!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !9}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DILocalVariable(name: "x", arg: 1, scope: !6, file: !1, line: 1, type: !9)
+!11 = !DIExpression()
+!12 = !DILocation(line: 1, column: 13, scope: !6)
+!13 = !DILocalVariable(name: "ret", scope: !6, file: !1, line: 2, type: !9)
+!14 = !DILocation(line: 2, column: 7, scope: !6)
+!15 = !DILocation(line: 3, column: 7, scope: !16)
+!16 = distinct !DILexicalBlock(scope: !6, file: !1, line: 3, column: 7)
+!17 = !DILocation(line: 3, column: 7, scope: !6)
+!18 = !DILocation(line: 4, column: 9, scope: !16)
+!19 = !DILocation(line: 4, column: 5, scope: !16)
+!20 = !DILocation(line: 5, column: 10, scope: !6)
+!21 = !DILocation(line: 5, column: 3, scope: !6)
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