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llvm-project/llvm/test/DebugInfo/X86/sdag-dbgvalue-phi-use-1.ll

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[SelectionDAG] Improve selection of DBG_VALUE using a PHI node result Summary: When building the selection DAG at ISel all PHI nodes are selected and lowered to Machine Instruction PHI nodes before we start to create any SDNodes. So there are no SDNodes for values produced by the PHI nodes. In the past when selecting a dbg.value intrinsic that uses the value produced by a PHI node we have been handling such dbg.value intrinsics as "dangling debug info". I.e. we have not created a SDDbgValue node directly, because there is no existing SDNode for the PHI result, instead we deferred the creationg of a SDDbgValue until we found the first use of the PHI result. The old solution had a couple of flaws. The position of the selected DBG_VALUE instruction would end up quite late in a basic block, and for example not directly after the PHI node as in the LLVM IR input. And in case there were no use at all in the basic block the dbg.value could be dropped completely. This patch introduces a new VREG kind of SDDbgValue nodes. It is similar to a SDNODE kind of node, but it refers directly to a virtual register and not a SDNode. When we do selection for a dbg.value that is using the result of a PHI node we can do a lookup of the virtual register directly (as it already is determined for the PHI node) and create a SDDbgValue node immediately instead of delaying the selection until we find a use. This should fix a problem with losing debug info at ISel as seen in PR37234 (https://bugs.llvm.org/show_bug.cgi?id=37234). It does not resolve PR37234 completely, because the debug info is dropped later on in the BranchFolder (see D46184). Reviewers: #debug-info, aprantl Reviewed By: #debug-info, aprantl Subscribers: rnk, gbedwell, aprantl, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D46129 llvm-svn: 331182
2018-04-30 22:37:39 +08:00
; RUN: llc -start-after=codegenprepare -stop-before expand-isel-pseudos -o - %s | FileCheck %s
; This test case was generated from the following debug.c program,
; using: clang debug.c -g -O1 -S -o dbg_value_phi_isel1.ll -emit-llvm
; --------------------------------------
; int end = 10;
;
; int main() {
; int x = 9;
; int y = 13;
; for (int u = 0; u < end; ++u) {
; x += y;
; y = y * 3;
; }
;
; volatile int arr[80];
; for (int q = 0; q < 64; ++q) {
; arr[q] = q + 3;
; }
;
; return x;
; }
; --------------------------------------
;
; ModuleID = 'debug.c'
source_filename = "debug.c"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@end = dso_local local_unnamed_addr global i32 10, align 4, !dbg !0
; Function Attrs: nounwind uwtable
define dso_local i32 @main() local_unnamed_addr #0 !dbg !11 {
; CHECK-LABEL: name: main
entry:
%arr = alloca [80 x i32], align 16
call void @llvm.dbg.value(metadata i32 9, metadata !15, metadata !DIExpression()), !dbg !26
call void @llvm.dbg.value(metadata i32 13, metadata !16, metadata !DIExpression()), !dbg !27
call void @llvm.dbg.value(metadata i32 0, metadata !17, metadata !DIExpression()), !dbg !28
%0 = load i32, i32* @end, align 4, !dbg !29, !tbaa !31
%cmp20 = icmp sgt i32 %0, 0, !dbg !35
br i1 %cmp20, label %for.body.lr.ph, label %for.cond.cleanup, !dbg !36
for.body.lr.ph: ; preds = %entry
%1 = load i32, i32* @end, align 4, !tbaa !31
br label %for.body, !dbg !36
for.cond.cleanup: ; preds = %for.body, %entry
; CHECK-LABEL: bb.{{.*}}.for.cond.cleanup:
; CHECK: [[REG1:%[0-9]+]]:gr32 = PHI
MachineOperand/MIParser: Do not print debug-use flag, infer it The debug-use flag must be set exactly for uses on DBG_VALUEs. This is so obvious that it can be trivially inferred while parsing. This will reduce noise when printing while omitting an information that has little value to the user. The parser will keep recognizing the flag for compatibility with old `.mir` files. Differential Revision: https://reviews.llvm.org/D53903 llvm-svn: 345671
2018-10-31 07:28:27 +08:00
; CHECK-NEXT: DBG_VALUE [[REG1]]
[SelectionDAG] Improve selection of DBG_VALUE using a PHI node result Summary: When building the selection DAG at ISel all PHI nodes are selected and lowered to Machine Instruction PHI nodes before we start to create any SDNodes. So there are no SDNodes for values produced by the PHI nodes. In the past when selecting a dbg.value intrinsic that uses the value produced by a PHI node we have been handling such dbg.value intrinsics as "dangling debug info". I.e. we have not created a SDDbgValue node directly, because there is no existing SDNode for the PHI result, instead we deferred the creationg of a SDDbgValue until we found the first use of the PHI result. The old solution had a couple of flaws. The position of the selected DBG_VALUE instruction would end up quite late in a basic block, and for example not directly after the PHI node as in the LLVM IR input. And in case there were no use at all in the basic block the dbg.value could be dropped completely. This patch introduces a new VREG kind of SDDbgValue nodes. It is similar to a SDNODE kind of node, but it refers directly to a virtual register and not a SDNode. When we do selection for a dbg.value that is using the result of a PHI node we can do a lookup of the virtual register directly (as it already is determined for the PHI node) and create a SDDbgValue node immediately instead of delaying the selection until we find a use. This should fix a problem with losing debug info at ISel as seen in PR37234 (https://bugs.llvm.org/show_bug.cgi?id=37234). It does not resolve PR37234 completely, because the debug info is dropped later on in the BranchFolder (see D46184). Reviewers: #debug-info, aprantl Reviewed By: #debug-info, aprantl Subscribers: rnk, gbedwell, aprantl, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D46129 llvm-svn: 331182
2018-04-30 22:37:39 +08:00
%x.0.lcssa = phi i32 [ 9, %entry ], [ %add, %for.body ]
call void @llvm.dbg.value(metadata i32 %x.0.lcssa, metadata !15, metadata !DIExpression()), !dbg !26
%2 = bitcast [80 x i32]* %arr to i8*, !dbg !37
call void @llvm.lifetime.start.p0i8(i64 320, i8* nonnull %2) #3, !dbg !37
call void @llvm.dbg.declare(metadata [80 x i32]* %arr, metadata !19, metadata !DIExpression()), !dbg !38
call void @llvm.dbg.value(metadata i32 0, metadata !24, metadata !DIExpression()), !dbg !39
br label %for.body4, !dbg !40
for.body: ; preds = %for.body.lr.ph, %for.body
; CHECK-LABEL: bb.{{.*}}.for.body:
; CHECK: [[REG2:%[0-9]+]]:gr32 = PHI
; CHECK-NEXT: [[REG3:%[0-9]+]]:gr32 = PHI
; CHECK-NEXT: [[REG4:%[0-9]+]]:gr32 = PHI
MachineOperand/MIParser: Do not print debug-use flag, infer it The debug-use flag must be set exactly for uses on DBG_VALUEs. This is so obvious that it can be trivially inferred while parsing. This will reduce noise when printing while omitting an information that has little value to the user. The parser will keep recognizing the flag for compatibility with old `.mir` files. Differential Revision: https://reviews.llvm.org/D53903 llvm-svn: 345671
2018-10-31 07:28:27 +08:00
; CHECK-NEXT: DBG_VALUE [[REG2]]
; CHECK-NEXT: DBG_VALUE [[REG3]]
; CHECK-NEXT: DBG_VALUE [[REG4]]
[SelectionDAG] Improve selection of DBG_VALUE using a PHI node result Summary: When building the selection DAG at ISel all PHI nodes are selected and lowered to Machine Instruction PHI nodes before we start to create any SDNodes. So there are no SDNodes for values produced by the PHI nodes. In the past when selecting a dbg.value intrinsic that uses the value produced by a PHI node we have been handling such dbg.value intrinsics as "dangling debug info". I.e. we have not created a SDDbgValue node directly, because there is no existing SDNode for the PHI result, instead we deferred the creationg of a SDDbgValue until we found the first use of the PHI result. The old solution had a couple of flaws. The position of the selected DBG_VALUE instruction would end up quite late in a basic block, and for example not directly after the PHI node as in the LLVM IR input. And in case there were no use at all in the basic block the dbg.value could be dropped completely. This patch introduces a new VREG kind of SDDbgValue nodes. It is similar to a SDNODE kind of node, but it refers directly to a virtual register and not a SDNode. When we do selection for a dbg.value that is using the result of a PHI node we can do a lookup of the virtual register directly (as it already is determined for the PHI node) and create a SDDbgValue node immediately instead of delaying the selection until we find a use. This should fix a problem with losing debug info at ISel as seen in PR37234 (https://bugs.llvm.org/show_bug.cgi?id=37234). It does not resolve PR37234 completely, because the debug info is dropped later on in the BranchFolder (see D46184). Reviewers: #debug-info, aprantl Reviewed By: #debug-info, aprantl Subscribers: rnk, gbedwell, aprantl, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D46129 llvm-svn: 331182
2018-04-30 22:37:39 +08:00
%u.023 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
%y.022 = phi i32 [ 13, %for.body.lr.ph ], [ %mul, %for.body ]
%x.021 = phi i32 [ 9, %for.body.lr.ph ], [ %add, %for.body ]
call void @llvm.dbg.value(metadata i32 %u.023, metadata !17, metadata !DIExpression()), !dbg !28
call void @llvm.dbg.value(metadata i32 %y.022, metadata !16, metadata !DIExpression()), !dbg !27
call void @llvm.dbg.value(metadata i32 %x.021, metadata !15, metadata !DIExpression()), !dbg !26
%add = add nuw nsw i32 %y.022, %x.021, !dbg !41
%mul = mul nsw i32 %y.022, 3, !dbg !43
%inc = add nuw nsw i32 %u.023, 1, !dbg !44
call void @llvm.dbg.value(metadata i32 %inc, metadata !17, metadata !DIExpression()), !dbg !28
call void @llvm.dbg.value(metadata i32 %mul, metadata !16, metadata !DIExpression()), !dbg !27
call void @llvm.dbg.value(metadata i32 %add, metadata !15, metadata !DIExpression()), !dbg !26
%cmp = icmp slt i32 %inc, %1, !dbg !35
br i1 %cmp, label %for.body, label %for.cond.cleanup, !dbg !36, !llvm.loop !45
for.cond.cleanup3: ; preds = %for.body4
call void @llvm.lifetime.end.p0i8(i64 320, i8* nonnull %2) #3, !dbg !47
ret i32 %x.0.lcssa, !dbg !48
for.body4: ; preds = %for.body4, %for.cond.cleanup
%indvars.iv = phi i64 [ 0, %for.cond.cleanup ], [ %indvars.iv.next, %for.body4 ]
call void @llvm.dbg.value(metadata i64 %indvars.iv, metadata !24, metadata !DIExpression()), !dbg !39
%arrayidx = getelementptr inbounds [80 x i32], [80 x i32]* %arr, i64 0, i64 %indvars.iv, !dbg !49
%3 = trunc i64 %indvars.iv to i32, !dbg !52
%4 = add i32 %3, 3, !dbg !52
store volatile i32 %4, i32* %arrayidx, align 4, !dbg !52, !tbaa !31
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !53
call void @llvm.dbg.value(metadata i32 undef, metadata !24, metadata !DIExpression(DW_OP_plus_uconst, 1, DW_OP_stack_value)), !dbg !39
%exitcond = icmp eq i64 %indvars.iv.next, 64, !dbg !54
br i1 %exitcond, label %for.cond.cleanup3, label %for.body4, !dbg !40, !llvm.loop !55
}
; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #1
; Function Attrs: nounwind readnone speculatable
declare void @llvm.dbg.declare(metadata, metadata, metadata) #2
; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #1
; Function Attrs: nounwind readnone speculatable
declare void @llvm.dbg.value(metadata, metadata, metadata) #2
attributes #0 = { nounwind uwtable }
attributes #1 = { argmemonly nounwind }
attributes #2 = { nounwind readnone speculatable }
attributes #3 = { nounwind }
!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!7, !8, !9}
!llvm.ident = !{!10}
!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
!1 = distinct !DIGlobalVariable(name: "end", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 7.0.0 (x)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
!3 = !DIFile(filename: "debug.c", 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 7.0.0 (x)"}
[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label. In order to set breakpoints on labels and list source code around labels, we need collect debug information for labels, i.e., label name, the function label belong, line number in the file, and the address label located. In order to keep these information in LLVM IR and to allow backend to generate debug information correctly. We create a new kind of metadata for labels, DILabel. The format of DILabel is !DILabel(scope: !1, name: "foo", file: !2, line: 3) We hope to keep debug information as much as possible even the code is optimized. So, we create a new kind of intrinsic for label metadata to avoid the metadata is eliminated with basic block. The intrinsic will keep existing if we keep it from optimized out. The format of the intrinsic is llvm.dbg.label(metadata !1) It has only one argument, that is the DILabel metadata. The intrinsic will follow the label immediately. Backend could get the label metadata through the intrinsic's parameter. We also create DIBuilder API for labels to be used by Frontend. Frontend could use createLabel() to allocate DILabel objects, and use insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR. Differential Revision: https://reviews.llvm.org/D45024 Patch by Hsiangkai Wang. llvm-svn: 331841
2018-05-09 10:40:45 +08:00
!11 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 3, type: !12, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: true, unit: !2, retainedNodes: !14)
[SelectionDAG] Improve selection of DBG_VALUE using a PHI node result Summary: When building the selection DAG at ISel all PHI nodes are selected and lowered to Machine Instruction PHI nodes before we start to create any SDNodes. So there are no SDNodes for values produced by the PHI nodes. In the past when selecting a dbg.value intrinsic that uses the value produced by a PHI node we have been handling such dbg.value intrinsics as "dangling debug info". I.e. we have not created a SDDbgValue node directly, because there is no existing SDNode for the PHI result, instead we deferred the creationg of a SDDbgValue until we found the first use of the PHI result. The old solution had a couple of flaws. The position of the selected DBG_VALUE instruction would end up quite late in a basic block, and for example not directly after the PHI node as in the LLVM IR input. And in case there were no use at all in the basic block the dbg.value could be dropped completely. This patch introduces a new VREG kind of SDDbgValue nodes. It is similar to a SDNODE kind of node, but it refers directly to a virtual register and not a SDNode. When we do selection for a dbg.value that is using the result of a PHI node we can do a lookup of the virtual register directly (as it already is determined for the PHI node) and create a SDDbgValue node immediately instead of delaying the selection until we find a use. This should fix a problem with losing debug info at ISel as seen in PR37234 (https://bugs.llvm.org/show_bug.cgi?id=37234). It does not resolve PR37234 completely, because the debug info is dropped later on in the BranchFolder (see D46184). Reviewers: #debug-info, aprantl Reviewed By: #debug-info, aprantl Subscribers: rnk, gbedwell, aprantl, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D46129 llvm-svn: 331182
2018-04-30 22:37:39 +08:00
!12 = !DISubroutineType(types: !13)
!13 = !{!6}
!14 = !{!15, !16, !17, !19, !24}
!15 = !DILocalVariable(name: "x", scope: !11, file: !3, line: 4, type: !6)
!16 = !DILocalVariable(name: "y", scope: !11, file: !3, line: 5, type: !6)
!17 = !DILocalVariable(name: "u", scope: !18, file: !3, line: 6, type: !6)
!18 = distinct !DILexicalBlock(scope: !11, file: !3, line: 6, column: 3)
!19 = !DILocalVariable(name: "arr", scope: !11, file: !3, line: 11, type: !20)
!20 = !DICompositeType(tag: DW_TAG_array_type, baseType: !21, size: 2560, elements: !22)
!21 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !6)
!22 = !{!23}
!23 = !DISubrange(count: 80)
!24 = !DILocalVariable(name: "q", scope: !25, file: !3, line: 12, type: !6)
!25 = distinct !DILexicalBlock(scope: !11, file: !3, line: 12, column: 3)
!26 = !DILocation(line: 4, column: 7, scope: !11)
!27 = !DILocation(line: 5, column: 7, scope: !11)
!28 = !DILocation(line: 6, column: 12, scope: !18)
!29 = !DILocation(line: 6, column: 23, scope: !30)
!30 = distinct !DILexicalBlock(scope: !18, file: !3, line: 6, column: 3)
!31 = !{!32, !32, i64 0}
!32 = !{!"int", !33, i64 0}
!33 = !{!"omnipotent char", !34, i64 0}
!34 = !{!"Simple C/C++ TBAA"}
!35 = !DILocation(line: 6, column: 21, scope: !30)
!36 = !DILocation(line: 6, column: 3, scope: !18)
!37 = !DILocation(line: 11, column: 3, scope: !11)
!38 = !DILocation(line: 11, column: 16, scope: !11)
!39 = !DILocation(line: 12, column: 12, scope: !25)
!40 = !DILocation(line: 12, column: 3, scope: !25)
!41 = !DILocation(line: 7, column: 7, scope: !42)
!42 = distinct !DILexicalBlock(scope: !30, file: !3, line: 6, column: 33)
!43 = !DILocation(line: 8, column: 11, scope: !42)
!44 = !DILocation(line: 6, column: 28, scope: !30)
!45 = distinct !{!45, !36, !46}
!46 = !DILocation(line: 9, column: 3, scope: !18)
!47 = !DILocation(line: 17, column: 1, scope: !11)
!48 = !DILocation(line: 16, column: 3, scope: !11)
!49 = !DILocation(line: 13, column: 5, scope: !50)
!50 = distinct !DILexicalBlock(scope: !51, file: !3, line: 12, column: 32)
!51 = distinct !DILexicalBlock(scope: !25, file: !3, line: 12, column: 3)
!52 = !DILocation(line: 13, column: 12, scope: !50)
!53 = !DILocation(line: 12, column: 27, scope: !51)
!54 = !DILocation(line: 12, column: 21, scope: !51)
!55 = distinct !{!55, !40, !56}
!56 = !DILocation(line: 14, column: 3, scope: !25)