[llvm-commits] [llvm] r127834 - in /llvm/trunk: include/llvm/Transforms/Utils/Local.h lib/Transforms/InstCombine/InstructionCombining.cpp lib/Transforms/Utils/Local.cpp test/Transforms/InstCombine/debuginfo.ll
Eli Friedman
eli.friedman at gmail.com
Thu Mar 17 15:36:01 PDT 2011
On Thu, Mar 17, 2011 at 3:18 PM, Devang Patel <dpatel at apple.com> wrote:
> Author: dpatel
> Date: Thu Mar 17 17:18:16 2011
> New Revision: 127834
>
> URL: http://llvm.org/viewvc/llvm-project?rev=127834&view=rev
> Log:
> Try to not lose variable's debug info during instcombine.
> This is done by lowering dbg.declare intrinsic into dbg.value intrinsic.
> Radar 9143931.
This looks like the wrong solution to a problem only caused by a few
very specific pieces of instcombine. Adding an extra iteration over
every instruction in the function isn't cheap, and it looks like this
could do some serious damage to the debug info for cases other than
the given testcase.
-Eli
> Added:
> llvm/trunk/test/Transforms/InstCombine/debuginfo.ll
> Modified:
> llvm/trunk/include/llvm/Transforms/Utils/Local.h
> llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
> llvm/trunk/lib/Transforms/Utils/Local.cpp
>
> 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=127834&r1=127833&r2=127834&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
> +++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Thu Mar 17 17:18:16 2011
> @@ -19,6 +19,7 @@
>
> class User;
> class BasicBlock;
> +class Function;
> class BranchInst;
> class Instruction;
> class DbgDeclareInst;
> @@ -169,6 +170,10 @@
> bool ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
> StoreInst *SI, DIBuilder &Builder);
>
> +/// LowerDbgDeclare - Lowers llvm.dbg.declare intrinsics into appropriate set
> +/// of llvm.dbg.value intrinsics.
> +bool LowerDbgDeclare(Function &F);
> +
> } // End llvm namespace
>
> #endif
>
> Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=127834&r1=127833&r2=127834&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
> +++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Thu Mar 17 17:18:16 2011
> @@ -1648,6 +1648,10 @@
>
> bool EverMadeChange = false;
>
> + // Lower dbg.declare intrinsics otherwise their value may be clobbered
> + // by instcombiner.
> + EverMadeChange = LowerDbgDeclare(F);
> +
> // Iterate while there is work to do.
> unsigned Iteration = 0;
> while (DoOneIteration(F, Iteration++))
>
> Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=127834&r1=127833&r2=127834&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
> +++ llvm/trunk/lib/Transforms/Utils/Local.cpp Thu Mar 17 17:18:16 2011
> @@ -783,3 +783,29 @@
> return true;
> }
>
> +/// LowerDbgDeclare - Lowers llvm.dbg.declare intrinsics into appropriate set
> +/// of llvm.dbg.value intrinsics.
> +bool llvm::LowerDbgDeclare(Function &F) {
> + DIBuilder DIB(*F.getParent());
> + SmallVector<DbgDeclareInst *, 4> Dbgs;
> + for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
> + for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ++BI) {
> + if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI))
> + Dbgs.push_back(DDI);
> + }
> + if (Dbgs.empty())
> + return false;
> +
> + for (SmallVector<DbgDeclareInst *, 4>::iterator I = Dbgs.begin(),
> + E = Dbgs.end(); I != E; ++I) {
> + DbgDeclareInst *DDI = *I;
> + if (AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress())) {
> + for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
> + UI != E; ++UI)
> + if (StoreInst *SI = dyn_cast<StoreInst>(*UI))
> + ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
> + }
> + DDI->eraseFromParent();
> + }
> + return true;
> +}
>
> Added: llvm/trunk/test/Transforms/InstCombine/debuginfo.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/debuginfo.ll?rev=127834&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/InstCombine/debuginfo.ll (added)
> +++ llvm/trunk/test/Transforms/InstCombine/debuginfo.ll Thu Mar 17 17:18:16 2011
> @@ -0,0 +1,57 @@
> +; RUN: opt < %s -instcombine -S | FileCheck %s
> +
> +declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
> +
> +declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readnone
> +
> +declare i8* @foo(i8*, i32, i64, i64) nounwind
> +
> +define hidden i8* @foobar(i8* %__dest, i32 %__val, i64 %__len) nounwind inlinehint ssp {
> +entry:
> + %__dest.addr = alloca i8*, align 8
> + %__val.addr = alloca i32, align 4
> + %__len.addr = alloca i64, align 8
> + store i8* %__dest, i8** %__dest.addr, align 8, !tbaa !1
> +; CHECK-NOT: call void @llvm.dbg.declare
> +; CHECK: call void @llvm.dbg.value
> + call void @llvm.dbg.declare(metadata !{i8** %__dest.addr}, metadata !0), !dbg !16
> + store i32 %__val, i32* %__val.addr, align 4, !tbaa !17
> + call void @llvm.dbg.declare(metadata !{i32* %__val.addr}, metadata !7), !dbg !18
> + store i64 %__len, i64* %__len.addr, align 8, !tbaa !19
> + call void @llvm.dbg.declare(metadata !{i64* %__len.addr}, metadata !9), !dbg !20
> + %tmp = load i8** %__dest.addr, align 8, !dbg !21, !tbaa !13
> + %tmp1 = load i32* %__val.addr, align 4, !dbg !21, !tbaa !17
> + %tmp2 = load i64* %__len.addr, align 8, !dbg !21, !tbaa !19
> + %tmp3 = load i8** %__dest.addr, align 8, !dbg !21, !tbaa !13
> + %0 = call i64 @llvm.objectsize.i64(i8* %tmp3, i1 false), !dbg !21
> + %call = call i8* @foo(i8* %tmp, i32 %tmp1, i64 %tmp2, i64 %0), !dbg !21
> + ret i8* %call, !dbg !21
> +}
> +
> +!llvm.dbg.lv.foobar = !{!0, !7, !9}
> +!llvm.dbg.sp = !{!1}
> +
> +!0 = metadata !{i32 590081, metadata !1, metadata !"__dest", metadata !2, i32 16777294, metadata !6, i32 0} ; [ DW_TAG_arg_variable ]
> +!1 = metadata !{i32 589870, i32 0, metadata !2, metadata !"foobar", metadata !"foobar", metadata !"", metadata !2, i32 79, metadata !4, i1 true, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, i8* (i8*, i32, i64)* @foobar} ; [ DW_TAG_subprogram ]
> +!2 = metadata !{i32 589865, metadata !"string.h", metadata !"Game", metadata !3} ; [ DW_TAG_file_type ]
> +!3 = metadata !{i32 589841, i32 0, i32 12, metadata !"bits.c", metadata !"Game", metadata !"clang version 3.0 (trunk 127710)", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
> +!4 = metadata !{i32 589845, metadata !2, metadata !"", metadata !2, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !5, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
> +!5 = metadata !{metadata !6}
> +!6 = metadata !{i32 589839, metadata !3, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, null} ; [ DW_TAG_pointer_type ]
> +!7 = metadata !{i32 590081, metadata !1, metadata !"__val", metadata !2, i32 33554510, metadata !8, i32 0} ; [ DW_TAG_arg_variable ]
> +!8 = metadata !{i32 589860, metadata !3, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
> +!9 = metadata !{i32 590081, metadata !1, metadata !"__len", metadata !2, i32 50331726, metadata !10, i32 0} ; [ DW_TAG_arg_variable ]
> +!10 = metadata !{i32 589846, metadata !3, metadata !"size_t", metadata !2, i32 80, i64 0, i64 0, i64 0, i32 0, metadata !11} ; [ DW_TAG_typedef ]
> +!11 = metadata !{i32 589846, metadata !3, metadata !"__darwin_size_t", metadata !2, i32 90, i64 0, i64 0, i64 0, i32 0, metadata !12} ; [ DW_TAG_typedef ]
> +!12 = metadata !{i32 589860, metadata !3, metadata !"long unsigned int", null, i32 0, i64 64, i64 64, i64 0, i32 0, i32 7} ; [ DW_TAG_base_type ]
> +!13 = metadata !{metadata !"any pointer", metadata !14}
> +!14 = metadata !{metadata !"omnipotent char", metadata !15}
> +!15 = metadata !{metadata !"Simple C/C++ TBAA", null}
> +!16 = metadata !{i32 78, i32 28, metadata !1, null}
> +!17 = metadata !{metadata !"int", metadata !14}
> +!18 = metadata !{i32 78, i32 40, metadata !1, null}
> +!19 = metadata !{metadata !"long", metadata !14}
> +!20 = metadata !{i32 78, i32 54, metadata !1, null}
> +!21 = metadata !{i32 80, i32 3, metadata !22, null}
> +!22 = metadata !{i32 589835, metadata !23, i32 80, i32 3, metadata !2, i32 7} ; [ DW_TAG_lexical_block ]
> +!23 = metadata !{i32 589835, metadata !1, i32 79, i32 1, metadata !2, i32 6} ; [ DW_TAG_lexical_block ]
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
More information about the llvm-commits
mailing list