[CodeGen] Fix bugs in LiveDebugVariables when debug labels are generated.

Remove DBG_LABELs in LiveDebugVariables and generate them in
VirtRegRewriter.

This bug is reported in
https://bugs.chromium.org/p/chromium/issues/detail?id=898152.

Differential Revision: https://reviews.llvm.org/D54465

llvm-svn: 351525

1 files changed, 141 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Generic/live-debug-label.ll b/llvm/test/CodeGen/Generic/live-debug-label.ll
new file mode 100644
index 00000000000..6f2f06a69ad
--- /dev/null
+++ b/llvm/test/CodeGen/Generic/live-debug-label.ll
@@ -0,0 +1,141 @@
+; RUN: llc < %s -stop-after=virtregrewriter -o - | FileCheck %s
+;
+; Generated with "clang++ -g -O1 -S -emit-llvm"
+;
+; inline bool bar(char c) {
+;   return c >= '0' && c <= '9';
+; }
+;
+; unsigned foo(const char* data,
+;              int length,
+;              int* parsing_result) {
+;   unsigned value = 0;
+;   int result = 1;
+;   bool overflow = 0;
+;
+;   while (bar(*data)) {
+;     if (value > 1) {
+;       result = 2;
+;       overflow = 1;
+;     }
+;
+;     if (!overflow)
+;       value = value + 1;
+;   }
+;
+;   if (length == 0 || value) {
+;     if (!overflow)
+;       result = 0;
+;   } else {
+;     result = 1;
+;   }
+; bye:
+;   *parsing_result = result;
+;   return result == 0 ? value : 0;
+; }
+;
+; CHECK: {{^body:}}
+; CHECK: bye.thread21:
+; CHECK: DBG_LABEL !14
+; CHECK: if.then5:
+; CHECK: DBG_LABEL !14
+; CHECK-NOT: DBG_LABEL !14
+
+$_Z3barc = comdat any
+
+; Function Attrs: nounwind uwtable
+define dso_local i32 @_Z3fooPKciPi(i8* nocapture readonly %data, i32 %length, i32* nocapture %parsing_result) local_unnamed_addr !dbg !4 {
+entry:
+  %0 = load i8, i8* %data, align 1
+  %call23 = tail call zeroext i1 @_Z3barc(i8 signext %0), !dbg !15
+  br i1 %call23, label %while.body, label %while.end
+
+while.body:                                       ; preds = %entry, %while.body
+  %overflow.026 = phi i8 [ %spec.select18, %while.body ], [ 0, %entry ]
+  %result.025 = phi i32 [ %spec.select, %while.body ], [ 1, %entry ]
+  %value.024 = phi i32 [ %value.1, %while.body ], [ 0, %entry ]
+  %cmp = icmp ugt i32 %value.024, 1
+  %spec.select = select i1 %cmp, i32 2, i32 %result.025
+  %spec.select18 = select i1 %cmp, i8 1, i8 %overflow.026
+  %1 = and i8 %spec.select18, 1
+  %2 = xor i8 %1, 1
+  %3 = zext i8 %2 to i32
+  %value.1 = add i32 %value.024, %3
+  %4 = load i8, i8* %data, align 1
+  %call = tail call zeroext i1 @_Z3barc(i8 signext %4), !dbg !15
+  br i1 %call, label %while.body, label %while.end.loopexit
+
+while.end.loopexit:                               ; preds = %while.body
+  %phitmp = and i8 %spec.select18, 1
+  br label %while.end
+
+while.end:                                        ; preds = %while.end.loopexit, %entry
+  %value.0.lcssa = phi i32 [ 0, %entry ], [ %value.1, %while.end.loopexit ]
+  %result.0.lcssa = phi i32 [ 1, %entry ], [ %spec.select, %while.end.loopexit ]
+  %overflow.0.lcssa = phi i8 [ 0, %entry ], [ %phitmp, %while.end.loopexit ]
+  %cmp3 = icmp eq i32 %length, 0
+  %tobool4 = icmp ne i32 %value.0.lcssa, 0
+  %or.cond = or i1 %cmp3, %tobool4
+  br i1 %or.cond, label %if.then5, label %bye.thread21
+
+bye.thread21:                                     ; preds = %while.end
+  call void @llvm.dbg.label(metadata !14), !dbg !16
+  store i32 1, i32* %parsing_result, align 4
+  br label %6
+
+if.then5:                                         ; preds = %while.end
+  %tobool6 = icmp eq i8 %overflow.0.lcssa, 0
+  call void @llvm.dbg.label(metadata !14), !dbg !16
+  call void @llvm.dbg.label(metadata !14), !dbg !16
+  br i1 %tobool6, label %bye.thread, label %bye
+
+bye.thread:                                       ; preds = %if.then5
+  store i32 0, i32* %parsing_result, align 4
+  br label %5
+
+bye:                                              ; preds = %if.then5
+  store i32 %result.0.lcssa, i32* %parsing_result, align 4
+  %cmp10 = icmp eq i32 %result.0.lcssa, 0
+  br i1 %cmp10, label %5, label %6
+
+; <label>:5:                                      ; preds = %bye.thread, %bye
+  br label %6
+
+; <label>:6:                                      ; preds = %bye.thread21, %bye, %5
+  %7 = phi i32 [ %value.0.lcssa, %5 ], [ 0, %bye ], [ 0, %bye.thread21 ]
+  ret i32 %7
+}
+
+; Function Attrs: inlinehint nounwind uwtable
+define linkonce_odr dso_local zeroext i1 @_Z3barc(i8 signext %c) local_unnamed_addr comdat {
+entry:
+  %c.off = add i8 %c, -48
+  %0 = icmp ult i8 %c.off, 10
+  ret i1 %0
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.label(metadata) #0
+
+attributes #0 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "live-debug-label.cc", directory: ".")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = distinct !DISubprogram(name: "foo", linkageName: "_Z3fooPKciPi", scope: !1, file: !1, line: 5, type: !5, isLocal: false, isDefinition: true, scopeLine: 7, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !13)
+!5 = !DISubroutineType(types: !6)
+!6 = !{!7, !8, !11, !12}
+!7 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
+!9 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !10)
+!10 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64)
+!13 = !{!14}
+!14 = !DILabel(scope: !4, name: "bye", file: !1, line: 28)
+!15 = !DILocation(line: 12, column: 10, scope: !4)
+!16 = !DILocation(line: 28, column: 1, scope: !4)