From cecc5431c0852c404cc4ceed112bee511898a49f Mon Sep 17 00:00:00 2001 From: Robert Lougher Date: Thu, 12 Jan 2017 20:34:35 +0000 Subject: [PATCH] [DebugInfo] Handle same locations in DILocation::getMergedLocation Revision 289661 introduced the function DILocation::getMergedLocation for merging of debug locations. At the time is was simply a stub which always returned no location. This patch modifies getMergedLocation to handle the case where the two locations are the same or can't be discriminated. Differential Revision: https://reviews.llvm.org/D28521 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291809 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/IR/DebugInfoMetadata.h | 25 ++++++------ .../Generic/simplifycfg_sink_last_inst.ll | 40 +++++++++++++++++++ 2 files changed, 52 insertions(+), 13 deletions(-) diff --git a/include/llvm/IR/DebugInfoMetadata.h b/include/llvm/IR/DebugInfoMetadata.h index 26f4626ead1..187855225c5 100644 --- a/include/llvm/IR/DebugInfoMetadata.h +++ b/include/llvm/IR/DebugInfoMetadata.h @@ -1295,16 +1295,12 @@ public: /// Check \c this can be discriminated from \c RHS in a linetable entry. /// Scope and inlined-at chains are not recorded in the linetable, so they /// cannot be used to distinguish basic blocks. - /// - /// The current implementation is weaker than it should be, since it just - /// checks filename and line. - /// - /// FIXME: Add a check for getDiscriminator(). - /// FIXME: Add a check for getColumn(). - /// FIXME: Change the getFilename() check to getFile() (or add one for - /// getDirectory()). bool canDiscriminate(const DILocation &RHS) const { - return getFilename() != RHS.getFilename() || getLine() != RHS.getLine(); + return getLine() != RHS.getLine() || + getColumn() != RHS.getColumn() || + getDiscriminator() != RHS.getDiscriminator() || + getFilename() != RHS.getFilename() || + getDirectory() != RHS.getDirectory(); } /// Get the DWARF discriminator. @@ -1327,10 +1323,13 @@ public: /// represented in a single line entry. In this case, no location /// should be set. /// - /// Currently this function is simply a stub, and no location will be - /// used for all cases. - static DILocation *getMergedLocation(const DILocation *LocA, - const DILocation *LocB) { + /// Currently the function does not create a new location. If the locations + /// are the same, or cannot be discriminated, the first location is returned. + /// Otherwise an empty location will be used. + static const DILocation *getMergedLocation(const DILocation *LocA, + const DILocation *LocB) { + if (LocA && LocB && (LocA == LocB || !LocA->canDiscriminate(*LocB))) + return LocA; return nullptr; } diff --git a/test/DebugInfo/Generic/simplifycfg_sink_last_inst.ll b/test/DebugInfo/Generic/simplifycfg_sink_last_inst.ll index a62def35acc..2185fbb845e 100644 --- a/test/DebugInfo/Generic/simplifycfg_sink_last_inst.ll +++ b/test/DebugInfo/Generic/simplifycfg_sink_last_inst.ll @@ -48,6 +48,43 @@ if.end: ; preds = %if.else, %if.then ret i32 %b.addr.0, !dbg !14 } +; When the commoned instructions have the same debug location, this location +; should be used as the location of the common instruction. + +; Generated from source (with -mllvm -no-discriminators and -gno-column-info): + +; int test2(int a, int b) { +; if(a) b -= foo(); else b -= bar(); +; return b; +; } + +; CHECK: define i32 @test2 +; CHECK-LABEL: if.end: +; CHECK: %[[PHI:.*]] = phi i32 [ %call1, %if.else ], [ %call, %if.then ] +; CHECK: sub nsw i32 %b, %[[PHI]], !dbg ![[DBG:.*]] +; CHECK: ret i32 +; CHECK: ![[DBG]] = !DILocation(line: 17, scope: !{{.*}}) + +define i32 @test2(i32 %a, i32 %b) !dbg !15 { +entry: + %tobool = icmp ne i32 %a, 0, !dbg !16 + br i1 %tobool, label %if.then, label %if.else, !dbg !16 + +if.then: ; preds = %entry + %call = call i32 @foo(), !dbg !16 + %sub = sub nsw i32 %b, %call, !dbg !16 + br label %if.end, !dbg !16 + +if.else: ; preds = %entry + %call1 = call i32 @bar(), !dbg !16 + %sub2 = sub nsw i32 %b, %call1, !dbg !16 + 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 !17 +} + declare i32 @foo() declare i32 @bar() @@ -68,3 +105,6 @@ declare i32 @bar() !12 = !DILocation(line: 12, column: 10, scope: !6) !13 = !DILocation(line: 12, column: 7, scope: !6) !14 = !DILocation(line: 13, column: 3, scope: !6) +!15 = distinct !DISubprogram(name: "test2", scope: !1, file: !1, line: 16, type: !7, isLocal: false, isDefinition: true, scopeLine: 16, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2) +!16 = !DILocation(line: 17, scope: !15) +!17 = !DILocation(line: 18, scope: !15) -- 2.40.0