[llvm] r345250 - [DebugInfo][Dexter] Unreachable line stepped onto after SimplifyCFG.

Mikael Holmén via llvm-commits llvm-commits at lists.llvm.org
Mon Jan 28 06:39:57 PST 2019



On 1/28/19 3:35 PM, Carlos Alberto Enciso wrote:
> Hi Mikael,
> 
> That case is a good finding. Great catch. Thanks for the test
> case.
> 
> Your suggested change to drop all DbgInfoIntrinsic instead of
> just DbgVariableIntrinsic, makes perfect sense.
> 
> I have applied that change to my local copy and all the test
> seems to pass.
> 
> Do you want to submit that change or do you prefer if I do it.
> Either way is fine with me.
> 

I'm happy if you do it :)

THe big comment in llvm::hoistAllInstructionsInto mentions dbg.values 
explicitly several times, I suppose it would be good to generalize that 
to talk about dbg intrinsics in general if we generalize the code.

Thanks,
Mikael

> Best regards,
> Carlos
> 
> On Mon, Jan 28, 2019 at 9:12 AM Mikael Holmén 
> <mikael.holmen at ericsson.com <mailto:mikael.holmen at ericsson.com>> wrote:
> 
>     Hi Carlos,
> 
>     I've stumbled on a case where the verifier complains with this change.
>     With
> 
>        opt -S -o - bbi-23595.ll -simplifycfg
> 
>     you get
> 
>     llvm.dbg.label intrinsic requires a !dbg attachment
>         call void @llvm.dbg.label(metadata !1)
>     label %entry
>     i16 ()* @_Z7test_itv
>     in function _Z7test_itv
>     LLVM ERROR: Broken function found, compilation aborted!
> 
>     With -print-after-all:
> 
>     *** IR Dump After Simplify the CFG ***
>     define i16 @_Z7test_itv() {
>     entry:
>         call void @llvm.dbg.label(metadata !1)
>         %retval.0 = select i1 undef, i16 1, i16 0
>         ret i16 0
>     }
> 
>     So simplifycfg has dropped the !dbg from the dbg.label, but kept the
>     instruction itself.
> 
>     Should perhaps
> 
>     +    if (isa<DbgVariableIntrinsic>(I)) {
>     +      // Remove DbgInfo Intrinsics.
>     +      II = I->eraseFromParent();
>     +      continue;
>     +    }
> 
>     in llvm::hoistAllInstructionsInto drop all DbgInfoIntrinsic instead of
>     just DbgVariableIntrinsic ?
> 
>     Regards,
>     Mikael
> 
> 
>     On 10/25/18 11:58 AM, Carlos Alberto Enciso via llvm-commits wrote:
>      > Author: carlos.alberto.enciso
>      > Date: Thu Oct 25 02:58:59 2018
>      > New Revision: 345250
>      >
>      > URL: http://llvm.org/viewvc/llvm-project?rev=345250&view=rev
>      > Log:
>      > [DebugInfo][Dexter] Unreachable line stepped onto after SimplifyCFG.
>      >
>      > When SimplifyCFG changes the PHI node into a select instruction,
>     the debug line records becomes ambiguous. It causes the debugger to
>     display unreachable source lines.
>      >
>      > Differential Revision: https://reviews.llvm.org/D53287
>      >
>      > Added:
>      >      llvm/trunk/test/CodeGen/X86/pr38762.ll
>      >      llvm/trunk/test/CodeGen/X86/pr39243.ll
>      > Modified:
>      >      llvm/trunk/include/llvm/Transforms/Utils/Local.h
>      >      llvm/trunk/lib/Transforms/Utils/Local.cpp
>      >      llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
>      >      llvm/trunk/test/CodeGen/X86/pr38763.ll
>      >
>      > Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=345250&r1=345249&r2=345250&view=diff
>      >
>     ==============================================================================
>      > --- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
>      > +++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Thu Oct 25
>     02:58:59 2018
>      > @@ -446,6 +446,15 @@ void copyRangeMetadata(const DataLayout
>      >   /// Remove the debug intrinsic instructions for the given
>     instruction.
>      >   void dropDebugUsers(Instruction &I);
>      >
>      > +/// Hoist all of the instructions in the \p IfBlock to the
>     dominant block
>      > +/// \p DomBlock, by moving its instructions to the insertion
>     point \p InsertPt.
>      > +///
>      > +/// The moved instructions receive the insertion point debug
>     location values
>      > +/// (DILocations) and their debug intrinsic instructions
>     (dbg.values) are
>      > +/// removed.
>      > +void hoistAllInstructionsInto(BasicBlock *DomBlock, Instruction
>     *InsertPt,
>      > +                              BasicBlock *BB);
>      > +
>      > 
>       //===----------------------------------------------------------------------===//
>      >   //  Intrinsic pattern matching
>      >   //
>      >
>      > Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=345250&r1=345249&r2=345250&view=diff
>      >
>     ==============================================================================
>      > --- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
>      > +++ llvm/trunk/lib/Transforms/Utils/Local.cpp Thu Oct 25 02:58:59
>     2018
>      > @@ -2529,6 +2529,47 @@ void llvm::dropDebugUsers(Instruction &I
>      >       DII->eraseFromParent();
>      >   }
>      >
>      > +void llvm::hoistAllInstructionsInto(BasicBlock *DomBlock,
>     Instruction *InsertPt,
>      > +                                    BasicBlock *BB) {
>      > +  // Since we are moving the instructions out of its basic
>     block, we do not
>      > +  // retain their original debug locations (DILocations) and
>     debug intrinsic
>      > +  // instructions (dbg.values).
>      > +  //
>      > +  // Doing so would degrade the debugging experience and
>     adversely affect the
>      > +  // accuracy of profiling information.
>      > +  //
>      > +  // Currently, when hoisting the instructions, we take the
>     following actions:
>      > +  // - Remove their dbg.values.
>      > +  // - Set their debug locations to the values from the
>     insertion point.
>      > +  //
>      > +  // As per PR39141 (comment #8), the more fundamental reason
>     why the dbg.values
>      > +  // need to be deleted, is because there will not be any
>     instructions with a
>      > +  // DILocation in either branch left after performing the
>     transformation. We
>      > +  // can only insert a dbg.value after the two branches are
>     joined again.
>      > +  //
>      > +  // See PR38762, PR39243 for more details.
>      > +  //
>      > +  // TODO: Extend llvm.dbg.value to take more than one SSA Value
>     (PR39141) to
>      > +  // encode predicated DIExpressions that yield different
>     results on different
>      > +  // code paths.
>      > +  for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II
>     != IE;) {
>      > +    Instruction *I = &*II;
>      > +    I->dropUnknownNonDebugMetadata();
>      > +    if (I->isUsedByMetadata())
>      > +      dropDebugUsers(*I);
>      > +    if (isa<DbgVariableIntrinsic>(I)) {
>      > +      // Remove DbgInfo Intrinsics.
>      > +      II = I->eraseFromParent();
>      > +      continue;
>      > +    }
>      > +    I->setDebugLoc(InsertPt->getDebugLoc());
>      > +    ++II;
>      > +  }
>      > +  DomBlock->getInstList().splice(InsertPt->getIterator(),
>     BB->getInstList(),
>      > +                                 BB->begin(),
>      > +                               
>       BB->getTerminator()->getIterator());
>      > +}
>      > +
>      >   namespace {
>      >
>      >   /// A potential constituent of a bitreverse or bswap
>     expression. See
>      >
>      > Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=345250&r1=345249&r2=345250&view=diff
>      >
>     ==============================================================================
>      > --- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
>      > +++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Thu Oct 25
>     02:58:59 2018
>      > @@ -2375,24 +2375,10 @@ static bool FoldTwoEntryPHINode(PHINode
>      >
>      >     // Move all 'aggressive' instructions, which are defined in the
>      >     // conditional parts of the if's up to the dominating block.
>      > -  if (IfBlock1) {
>      > -    for (auto &I : *IfBlock1) {
>      > -      I.dropUnknownNonDebugMetadata();
>      > -      dropDebugUsers(I);
>      > -    }
>      > -    DomBlock->getInstList().splice(InsertPt->getIterator(),
>      > -                                   IfBlock1->getInstList(),
>     IfBlock1->begin(),
>      > -                                 
>       IfBlock1->getTerminator()->getIterator());
>      > -  }
>      > -  if (IfBlock2) {
>      > -    for (auto &I : *IfBlock2) {
>      > -      I.dropUnknownNonDebugMetadata();
>      > -      dropDebugUsers(I);
>      > -    }
>      > -    DomBlock->getInstList().splice(InsertPt->getIterator(),
>      > -                                   IfBlock2->getInstList(),
>     IfBlock2->begin(),
>      > -                                 
>       IfBlock2->getTerminator()->getIterator());
>      > -  }
>      > +  if (IfBlock1)
>      > +    hoistAllInstructionsInto(DomBlock, InsertPt, IfBlock1);
>      > +  if (IfBlock2)
>      > +    hoistAllInstructionsInto(DomBlock, InsertPt, IfBlock2);
>      >
>      >     while (PHINode *PN = dyn_cast<PHINode>(BB->begin())) {
>      >       // Change the PHI node into a select instruction.
>      >
>      > Added: llvm/trunk/test/CodeGen/X86/pr38762.ll
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr38762.ll?rev=345250&view=auto
>      >
>     ==============================================================================
>      > --- llvm/trunk/test/CodeGen/X86/pr38762.ll (added)
>      > +++ llvm/trunk/test/CodeGen/X86/pr38762.ll Thu Oct 25 02:58:59 2018
>      > @@ -0,0 +1,101 @@
>      > +; RUN: opt < %s -S -simplifycfg | FileCheck %s
>      > +
>      > +; Note: This patch is a complement to pr38763.
>      > +;
>      > +; When SimplifyCFG changes the PHI node into a select
>     instruction, the debug
>      > +; information becomes ambiguous. It causes the debugger to
>     display unreached
>      > +; lines and invalid variable values.
>      > +;
>      > +; When in the debugger, on the line "if (read1 > 3)", and we
>     step from the
>      > +; 'if' condition, onto the addition, then back to the 'if'
>     again, which is
>      > +; misleading because that addition doesn't really "happen" (it's
>     speculated).
>      > +
>      > +; IR generated with:
>      > +; clang -S -g -gno-column-info -O2 -emit-llvm pr38762.cpp -o
>     pr38762.ll -mllvm -opt-bisect-limit=10
>      > +
>      > +; // pr38762.cpp
>      > +; int main() {
>      > +;   volatile int foo = 0;
>      > +;   int read1 = foo;
>      > +;   int brains = foo;
>      > +;
>      > +;   if (read1 > 3) {
>      > +;     brains *= 2;
>      > +;     brains += 1;
>      > +;   }
>      > +;
>      > +;   return brains;
>      > +; }
>      > +
>      > +; Change the debug locations associated with the PHI nodes being
>     promoted, to
>      > +; the debug locations from the insertion point in the dominant
>     block.
>      > +
>      > +; CHECK-LABEL: entry
>      > +; CHECK:  %cmp = icmp sgt i32 %foo.0., 3, !dbg !14
>      > +; CHECK:  %mul = shl nsw i32 %foo.0.5, 1, !dbg !16
>      > +; CHECK-NOT:  call void @llvm.dbg.value(metadata i32 %mul,
>     metadata !15, metadata !DIExpression()), !dbg !25
>      > +; CHECK:  %add = or i32 %mul, 1, !dbg !16
>      > +; CHECK-NOT:  call void @llvm.dbg.value(metadata i32 %add,
>     metadata !15, metadata !DIExpression()), !dbg !25
>      > +; CHECK:  %brains.0 = select i1 %cmp, i32 %add, i32 %foo.0.5,
>     !dbg !16
>      > +
>      > +; ModuleID = 'pr38762.cpp'
>      > +source_filename = "pr38762.cpp"
>      > +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>      > +target triple = "x86_64-pc-linux-gnu"
>      > +
>      > +; Function Attrs: norecurse nounwind uwtable
>      > +define dso_local i32 @main() local_unnamed_addr #0 !dbg !7 {
>      > +entry:
>      > +  %foo = alloca i32, align 4
>      > +  %foo.0..sroa_cast = bitcast i32* %foo to i8*
>      > +  store volatile i32 0, i32* %foo, align 4
>      > +  %foo.0. = load volatile i32, i32* %foo, align 4
>      > +  %foo.0.5 = load volatile i32, i32* %foo, align 4
>      > +  call void @llvm.dbg.value(metadata i32 %foo.0.5, metadata !15,
>     metadata !DIExpression()), !dbg !25
>      > +  %cmp = icmp sgt i32 %foo.0., 3, !dbg !26
>      > +  br i1 %cmp, label %if.then, label %if.end, !dbg !28
>      > +
>      > +if.then:                                          ; preds = %entry
>      > +  %mul = shl nsw i32 %foo.0.5, 1, !dbg !29
>      > +  call void @llvm.dbg.value(metadata i32 %mul, metadata !15,
>     metadata !DIExpression()), !dbg !25
>      > +  %add = or i32 %mul, 1, !dbg !31
>      > +  call void @llvm.dbg.value(metadata i32 %add, metadata !15,
>     metadata !DIExpression()), !dbg !25
>      > +  br label %if.end, !dbg !32
>      > +
>      > +if.end:                                           ; preds =
>     %if.then, %entry
>      > +  %brains.0 = phi i32 [ %add, %if.then ], [ %foo.0.5, %entry ],
>     !dbg !33
>      > +  call void @llvm.dbg.value(metadata i32 %brains.0, metadata
>     !15, metadata !DIExpression()), !dbg !25
>      > +  ret i32 %brains.0, !dbg !35
>      > +}
>      > +
>      > +declare void @llvm.dbg.value(metadata, metadata, metadata) #2
>      > +
>      > +!llvm.dbg.cu <http://llvm.dbg.cu> = !{!0}
>      > +!llvm.module.flags = !{!3, !4, !5}
>      > +!llvm.ident = !{!6}
>      > +
>      > +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus,
>     file: !1, producer: "clang version 8.0.0 (trunk 343753)",
>     isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug,
>     enums: !2, nameTableKind: None)
>      > +!1 = !DIFile(filename: "pr38762.cpp", directory: ".")
>      > +!2 = !{}
>      > +!3 = !{i32 2, !"Dwarf Version", i32 4}
>      > +!4 = !{i32 2, !"Debug Info Version", i32 3}
>      > +!5 = !{i32 1, !"wchar_size", i32 4}
>      > +!6 = !{!"clang version 8.0.0 (trunk 343753)"}
>      > +!7 = distinct !DISubprogram(name: "main", scope: !1, file: !1,
>     line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1,
>     flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes:
>     !11)
>      > +!8 = !DISubroutineType(types: !9)
>      > +!9 = !{!10}
>      > +!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
>      > +!11 = !{!15}
>      > +!13 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !10)
>      > +!15 = !DILocalVariable(name: "brains", scope: !7, file: !1,
>     line: 4, type: !10)
>      > +!25 = !DILocation(line: 4, scope: !7)
>      > +!26 = !DILocation(line: 6, scope: !27)
>      > +!27 = distinct !DILexicalBlock(scope: !7, file: !1, line: 6)
>      > +!28 = !DILocation(line: 6, scope: !7)
>      > +!29 = !DILocation(line: 7, scope: !30)
>      > +!30 = distinct !DILexicalBlock(scope: !27, file: !1, line: 6)
>      > +!31 = !DILocation(line: 8, scope: !30)
>      > +!32 = !DILocation(line: 9, scope: !30)
>      > +!33 = !DILocation(line: 0, scope: !7)
>      > +!34 = !DILocation(line: 12, scope: !7)
>      > +!35 = !DILocation(line: 11, scope: !7)
>      >
>      > Modified: llvm/trunk/test/CodeGen/X86/pr38763.ll
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr38763.ll?rev=345250&r1=345249&r2=345250&view=diff
>      >
>     ==============================================================================
>      > --- llvm/trunk/test/CodeGen/X86/pr38763.ll (original)
>      > +++ llvm/trunk/test/CodeGen/X86/pr38763.ll Thu Oct 25 02:58:59 2018
>      > @@ -30,13 +30,13 @@
>      >   ; branches, as they becomes ambiguous.
>      >
>      >   ; CHECK-LABEL: entry
>      > -; CHECK:  %cmp = icmp eq i32 %foo.0., 4
>      > -; CHECK:  %add = add nsw i32 %foo.0.4, 2, !dbg !18
>      > +; CHECK:  %cmp = icmp eq i32 %foo.0., 4, !dbg !14
>      > +; CHECK:  %add = add nsw i32 %foo.0.4, 2, !dbg !16
>      >   ; CHECK-NOT: @llvm.dbg.value(metadata i32 %add
>      > -; CHECK:  %sub = add nsw i32 %foo.0.4, -2, !dbg !21
>      > +; CHECK:  %sub = add nsw i32 %foo.0.4, -2, !dbg !16
>      >   ; CHECK-NOT: @llvm.dbg.value(metadata i32 %sub
>      >   ; CHECK:  %result.0 = select i1 %cmp, i32 %add, i32 %sub
>      > -; CHECK:  call void @llvm.dbg.value(metadata i32 %result.0,
>     metadata !12, metadata !DIExpression()), !dbg !17
>      > +; CHECK:  call void @llvm.dbg.value(metadata i32 %result.0,
>     metadata !12, metadata !DIExpression()), !dbg !13
>      >
>      >   ; ModuleID = 'pr38763.cpp'
>      >   source_filename = "pr38763.cpp"
>      > @@ -48,12 +48,12 @@ define dso_local i32 @main() local_unnam
>      >   entry:
>      >     %foo = alloca i32, align 4
>      >     %foo.0..sroa_cast = bitcast i32* %foo to i8*
>      > -  store volatile i32 4, i32* %foo, align 4, !tbaa !19
>      > +  store volatile i32 4, i32* %foo, align 4
>      >     %foo.0. = load volatile i32, i32* %foo, align 4
>      >     %foo.0.4 = load volatile i32, i32* %foo, align 4
>      >     call void @llvm.dbg.value(metadata i32 0, metadata !16,
>     metadata !DIExpression()), !dbg !27
>      > -  %cmp = icmp eq i32 %foo.0., 4
>      > -  br i1 %cmp, label %if.then, label %if.else
>      > +  %cmp = icmp eq i32 %foo.0., 4, !dbg !28
>      > +  br i1 %cmp, label %if.then, label %if.else, !dbg !30
>      >
>      >   if.then:                                          ; preds = %entry
>      >     %add = add nsw i32 %foo.0.4, 2, !dbg !31
>      > @@ -91,12 +91,10 @@ declare void @llvm.dbg.value(metadata, m
>      >   !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
>      >   !11 = !{!16}
>      >   !16 = !DILocalVariable(name: "result", scope: !7, file: !1,
>     line: 6, type: !10)
>      > -!19 = !{!20, !20, i64 0}
>      > -!20 = !{!"int", !21, i64 0}
>      > -!21 = !{!"omnipotent char", !22, i64 0}
>      > -!22 = !{!"Simple C++ TBAA"}
>      >   !27 = !DILocation(line: 6, column: 7, scope: !7)
>      > +!28 = !DILocation(line: 7, column: 12, scope: !29)
>      >   !29 = distinct !DILexicalBlock(scope: !7, file: !1, line: 7,
>     column: 7)
>      > +!30 = !DILocation(line: 7, column: 7, scope: !7)
>      >   !31 = !DILocation(line: 8, column: 20, scope: !32)
>      >   !32 = distinct !DILexicalBlock(scope: !29, file: !1, line: 7,
>     column: 18)
>      >   !34 = !DILocation(line: 10, column: 20, scope: !35)
>      >
>      > Added: llvm/trunk/test/CodeGen/X86/pr39243.ll
>      > URL:
>     http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr39243.ll?rev=345250&view=auto
>      >
>     ==============================================================================
>      > --- llvm/trunk/test/CodeGen/X86/pr39243.ll (added)
>      > +++ llvm/trunk/test/CodeGen/X86/pr39243.ll Thu Oct 25 02:58:59 2018
>      > @@ -0,0 +1,132 @@
>      > +; RUN: opt < %s -S -simplifycfg | FileCheck %s
>      > +
>      > +; Note: This patch fixes the regression introduced by pr38762.
>      > +;
>      > +; When SimplifyCFG changes the PHI node into a select
>     instruction, the debug
>      > +; information becomes ambiguous. It causes the debugger to
>     display unreached
>      > +; lines and invalid variable values.
>      > +;
>      > +; When the function 'hoistAllInstructionsInto' hoist a basic block:
>      > +; - Remove their dbg.values.
>      > +; - Set their debug locations to the values from the insertion
>     point.
>      > +;
>      > +; But, if one of the instructions being hoisted is a debug
>     intrinsic from an
>      > +; inlined function, assigning it the debug location from the
>     insertion point
>      > +; will create a mismatch between the intrinsic's subprogram and
>     the location's
>      > +; subprogram, causing the assertion "Expected inlined-at fields
>     to agree" in
>      > +; SelectionDAG".
>      > +
>      > +; IR generated with:
>      > +; clang -S -g -gno-column-info -O2 -emit-llvm pr39243.cpp -o
>     pr39243.ll -mllvm -opt-bisect-limit=103
>      > +
>      > +; // pr39243.cpp
>      > +; union onion {
>      > +;   double dd;
>      > +;   int ii[2];
>      > +; };
>      > +;
>      > +; int alpha;
>      > +; int bravo();
>      > +;
>      > +; int charlie() {
>      > +;   int delta = 0;
>      > +;   return bravo();
>      > +; }
>      > +;
>      > +; int echo(onion foxtrot) {
>      > +;   alpha = foxtrot.ii[0];
>      > +;   if (alpha) {
>      > +;     int golf = bravo();
>      > +;     return -golf;
>      > +;   }
>      > +;   alpha = foxtrot.ii[1];
>      > +;   return -charlie();
>      > +; }
>      > +
>      > +; Change the debug locations associated with the PHI nodes being
>     promoted, to
>      > +; the debug locations from the insertion point in the dominant
>     block.
>      > +
>      > +; CHECK-LABEL: entry
>      > +; CHECK:  %foxtrot.sroa.0.0.extract.trunc = trunc i64
>     %foxtrot.coerce to i32
>      > +; CHECK:  %tobool = icmp eq i32 %foxtrot.sroa.0.0.extract.trunc, 0
>      > +; CHECK:  %foxtrot.sroa.2.0.extract.shift = lshr i64
>     %foxtrot.coerce, 32
>      > +; CHECK-NOT:  call void @llvm.dbg.value(metadata i32
>     %foxtrot.sroa.2.0.extract.trunc, metadata !30, metadata
>     !DIExpression(DW_OP_LLVM_fragment, 32, 32)), !dbg !34
>      > +; CHECK:  %foxtrot.sroa.2.0.extract.trunc = trunc i64
>     %foxtrot.sroa.2.0.extract.shift to i32
>      > +; CHECK:  store i32 %foxtrot.sroa.2.0.extract.trunc, i32*
>     @alpha, align 4, !dbg !25
>      > +; CHECK-NOT:  call void @llvm.dbg.value(metadata i32 0, metadata
>     !15, metadata !DIExpression()), !dbg !43
>      > +
>      > +; ModuleID = 'pr39243.cpp'
>      > +source_filename = "pr39243.cpp"
>      > +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>      > +target triple = "x86_64-pc-linux-gnu"
>      > +
>      > + at alpha = dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
>      > +
>      > +define dso_local i32 @_Z7charliev() local_unnamed_addr #0 {
>      > +entry:
>      > +  %call = tail call i32 @_Z5bravov()
>      > +  ret i32 %call
>      > +}
>      > +
>      > +declare dso_local i32 @_Z5bravov() local_unnamed_addr #1
>      > +
>      > +define dso_local i32 @_Z4echo5onion(i64 %foxtrot.coerce)
>     local_unnamed_addr #0 !dbg !18 {
>      > +entry:
>      > +  %foxtrot.sroa.0.0.extract.trunc = trunc i64 %foxtrot.coerce to i32
>      > +  store i32 %foxtrot.sroa.0.0.extract.trunc, i32* @alpha, align 4
>      > +  %tobool = icmp eq i32 %foxtrot.sroa.0.0.extract.trunc, 0
>      > +  br i1 %tobool, label %if.end, label %return
>      > +
>      > +if.end:                                           ; preds = %entry
>      > +  %foxtrot.sroa.2.0.extract.shift = lshr i64 %foxtrot.coerce, 32
>      > +  %foxtrot.sroa.2.0.extract.trunc = trunc i64
>     %foxtrot.sroa.2.0.extract.shift to i32
>      > +  call void @llvm.dbg.value(metadata i32
>     %foxtrot.sroa.2.0.extract.trunc, metadata !30, metadata
>     !DIExpression(DW_OP_LLVM_fragment, 32, 32)), !dbg !34
>      > +  store i32 %foxtrot.sroa.2.0.extract.trunc, i32* @alpha, align
>     4, !dbg !42
>      > +  call void @llvm.dbg.value(metadata i32 0, metadata !15,
>     metadata !DIExpression()), !dbg !43
>      > +  br label %return
>      > +
>      > +return:                                           ; preds =
>     %entry, %if.end
>      > +  %call.i = tail call i32 @_Z5bravov()
>      > +  %retval.0 = sub nsw i32 0, %call.i
>      > +  ret i32 %retval.0
>      > +}
>      > +
>      > +declare void @llvm.dbg.value(metadata, metadata, metadata) #2
>      > +
>      > +!llvm.dbg.cu <http://llvm.dbg.cu> = !{!2}
>      > +!llvm.module.flags = !{!7, !8, !9}
>      > +!llvm.ident = !{!10}
>      > +
>      > +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
>      > +!1 = distinct !DIGlobalVariable(name: "alpha", scope: !2, file:
>     !3, line: 6, type: !6, isLocal: false, isDefinition: true)
>      > +!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus,
>     file: !3, producer: "clang version 8.0.0 (trunk 344502)",
>     isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug,
>     enums: !4, globals: !5, nameTableKind: None)
>      > +!3 = !DIFile(filename: "pr39243.cpp", directory: ".")
>      > +!4 = !{}
>      > +!5 = !{!0}
>      > +!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
>      > +!7 = !{i32 2, !"Dwarf Version", i32 4}
>      > +!8 = !{i32 2, !"Debug Info Version", i32 3}
>      > +!9 = !{i32 1, !"wchar_size", i32 4}
>      > +!10 = !{!"clang version 8.0.0 (trunk 344502)"}
>      > +!11 = distinct !DISubprogram(name: "charlie", linkageName:
>     "_Z7charliev", scope: !3, file: !3, line: 9, type: !12, isLocal:
>     false, isDefinition: true, scopeLine: 9, flags: DIFlagPrototyped,
>     isOptimized: true, unit: !2, retainedNodes: !14)
>      > +!12 = !DISubroutineType(types: !13)
>      > +!13 = !{!6}
>      > +!14 = !{!15}
>      > +!15 = !DILocalVariable(name: "delta", scope: !11, file: !3,
>     line: 10, type: !6)
>      > +!18 = distinct !DISubprogram(name: "echo", linkageName:
>     "_Z4echo5onion", scope: !3, file: !3, line: 14, type: !19, isLocal:
>     false, isDefinition: true, scopeLine: 14, flags: DIFlagPrototyped,
>     isOptimized: true, unit: !2, retainedNodes: !29)
>      > +!19 = !DISubroutineType(types: !20)
>      > +!20 = !{!6, !21}
>      > +!21 = distinct !DICompositeType(tag: DW_TAG_union_type, name:
>     "onion", file: !3, line: 1, size: 64, flags: DIFlagTypePassByValue |
>     DIFlagTrivial, elements: !22, identifier: "_ZTS5onion")
>      > +!22 = !{!23, !25}
>      > +!23 = !DIDerivedType(tag: DW_TAG_member, name: "dd", scope: !21,
>     file: !3, line: 2, baseType: !24, size: 64)
>      > +!24 = !DIBasicType(name: "double", size: 64, encoding: DW_ATE_float)
>      > +!25 = !DIDerivedType(tag: DW_TAG_member, name: "ii", scope: !21,
>     file: !3, line: 3, baseType: !26, size: 64)
>      > +!26 = !DICompositeType(tag: DW_TAG_array_type, baseType: !6,
>     size: 64, elements: !27)
>      > +!27 = !{!28}
>      > +!28 = !DISubrange(count: 2)
>      > +!29 = !{!30}
>      > +!30 = !DILocalVariable(name: "foxtrot", arg: 1, scope: !18,
>     file: !3, line: 14, type: !21)
>      > +!34 = !DILocation(line: 14, scope: !18)
>      > +!42 = !DILocation(line: 20, scope: !18)
>      > +!43 = !DILocation(line: 10, scope: !11, inlinedAt: !44)
>      > +!44 = distinct !DILocation(line: 21, scope: !18)
>      >
>      >
>      > _______________________________________________
>      > llvm-commits mailing list
>      > llvm-commits at lists.llvm.org <mailto:llvm-commits at lists.llvm.org>
>      > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>      >
> 



More information about the llvm-commits mailing list