Invoke salvageDebugInfo from CodeGenPrepare's SinkCast()

This preserves the debug info for the cast operation in the original location.

rdar://problem/33460652

llvm-svn: 317340

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 973ddeb..73f0147 100644 (file)
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1171,6 +1171,7 @@ static bool SinkCast(CastInst *CI) {
 
   // If we removed all uses, nuke the cast.
   if (CI->use_empty()) {
+    salvageDebugInfo(*CI);
     CI->eraseFromParent();
     MadeChange = true;
   }

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 8c643c9..cb7978f 100644 (file)
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1366,7 +1366,7 @@ void llvm::salvageDebugInfo(Instruction &I) {
     return MetadataAsValue::get(I.getContext(), ValueAsMetadata::get(V));
   };
 
-  if (isa<BitCastInst>(&I)) {
+  if (isa<BitCastInst>(&I) || isa<IntToPtrInst>(&I)) {
     findDbgValues(DbgValues, &I);
     for (auto *DVI : DbgValues) {
       // Bitcasts are entirely irrelevant for debug info. Rewrite the dbg.value

diff --git a/llvm/test/Transforms/CodeGenPrepare/salvage-debug-info.ll b/llvm/test/Transforms/CodeGenPrepare/salvage-debug-info.ll
new file mode 100644 (file)
index 0000000..5509b92
--- /dev/null
+++ b/llvm/test/Transforms/CodeGenPrepare/salvage-debug-info.ll
@@ -0,0 +1,118 @@
+; RUN: opt -codegenprepare -S %s -o - | FileCheck %s
+; typedef struct info {
+;   unsigned long long size;
+; } info_t;
+; extern unsigned p;
+; extern unsigned n;
+; void f() {
+;   unsigned int i;
+;   if (p) {
+;     info_t *info = (info_t *)p;
+;     for (i = 0; i < n; i++)
+;       use(info[i].size);
+;   }
+; }
+source_filename = "debug.i"
+target datalayout = "e-m:o-p:32:32-i64:64-a:0:32-n32-S128"
+target triple = "thumbv7k-apple-ios10.0.0"
+
+%struct.info = type { i64 }
+
+@p = external local_unnamed_addr global i32, align 4
+@n = external local_unnamed_addr global i32, align 4
+
+; Function Attrs: nounwind ssp uwtable
+define void @f() local_unnamed_addr #0 !dbg !16 {
+entry:
+  %0 = load i32, i32* @p, align 4, !dbg !25
+  %tobool = icmp eq i32 %0, 0, !dbg !25
+  br i1 %tobool, label %if.end, label %if.then, !dbg !26
+
+if.then:                                          ; preds = %entry
+  %1 = inttoptr i32 %0 to %struct.info*, !dbg !27
+  tail call void @llvm.dbg.value(metadata %struct.info* %1, metadata !22, metadata !DIExpression()), !dbg !28
+  ; CHECK: call void @llvm.dbg.value(metadata i32 %0, metadata !22, metadata !DIExpression())
+  tail call void @llvm.dbg.value(metadata i32 0, metadata !20, metadata !DIExpression()), !dbg !29
+  %2 = load i32, i32* @n, align 4, !dbg !30
+  %cmp5 = icmp eq i32 %2, 0, !dbg !33
+  br i1 %cmp5, label %if.end, label %for.body.preheader, !dbg !34
+
+for.body.preheader:                               ; preds = %if.then
+  ; CHECK: for.body.preheader:
+  ; CHECK:   %2 = inttoptr i32 %0 to %struct.info*
+  br label %for.body, !dbg !35
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %lsr.iv = phi %struct.info* [ %1, %for.body.preheader ], [ %scevgep, %for.body ]
+  %i.06 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %lsr.iv7 = bitcast %struct.info* %lsr.iv to i64*
+  tail call void @llvm.dbg.value(metadata i32 %i.06, metadata !20, metadata !DIExpression()), !dbg !29
+  %3 = load i64, i64* %lsr.iv7, align 8, !dbg !35
+  %call = tail call i32 bitcast (i32 (...)* @use to i32 (i64)*)(i64 %3) #3, !dbg !36
+  %inc = add nuw i32 %i.06, 1, !dbg !37
+  tail call void @llvm.dbg.value(metadata i32 %inc, metadata !20, metadata !DIExpression()), !dbg !29
+  %4 = load i32, i32* @n, align 4, !dbg !30
+  %scevgep = getelementptr %struct.info, %struct.info* %lsr.iv, i32 1, !dbg !33
+  %cmp = icmp ult i32 %inc, %4, !dbg !33
+  br i1 %cmp, label %for.body, label %if.end.loopexit, !dbg !34, !llvm.loop !38
+
+if.end.loopexit:                                  ; preds = %for.body
+  br label %if.end, !dbg !40
+
+if.end:                                           ; preds = %if.end.loopexit, %if.then, %entry
+  ret void, !dbg !40
+}
+declare i32 @use(...) local_unnamed_addr #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind ssp uwtable }
+attributes #2 = { nounwind readnone speculatable }
+attributes #3 = { nobuiltin nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!10, !11, !12, !13, !14}
+!llvm.ident = !{!15}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 (trunk 317231) (llvm/trunk 317262)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3)
+!1 = !DIFile(filename: "debug.i", directory: "/Data/radar/35321562")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 32)
+!5 = !DIDerivedType(tag: DW_TAG_typedef, name: "info_t", file: !1, line: 3, baseType: !6)
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "info", file: !1, line: 1, size: 64, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "size", scope: !6, file: !1, line: 2, baseType: !9, size: 64)
+!9 = !DIBasicType(name: "long long unsigned int", size: 64, encoding: DW_ATE_unsigned)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{i32 1, !"min_enum_size", i32 4}
+!14 = !{i32 7, !"PIC Level", i32 2}
+!15 = !{!"clang version 6.0.0 (trunk 317231) (llvm/trunk 317262)"}
+!16 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 6, type: !17, isLocal: false, isDefinition: true, scopeLine: 6, isOptimized: true, unit: !0, variables: !19)
+!17 = !DISubroutineType(types: !18)
+!18 = !{null}
+!19 = !{!20, !22}
+!20 = !DILocalVariable(name: "i", scope: !16, file: !1, line: 7, type: !21)
+!21 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!22 = !DILocalVariable(name: "info", scope: !23, file: !1, line: 9, type: !4)
+!23 = distinct !DILexicalBlock(scope: !24, file: !1, line: 8, column: 10)
+!24 = distinct !DILexicalBlock(scope: !16, file: !1, line: 8, column: 7)
+!25 = !DILocation(line: 8, column: 7, scope: !24)
+!26 = !DILocation(line: 8, column: 7, scope: !16)
+!27 = !DILocation(line: 9, column: 20, scope: !23)
+!28 = !DILocation(line: 9, column: 13, scope: !23)
+!29 = !DILocation(line: 7, column: 16, scope: !16)
+!30 = !DILocation(line: 10, column: 21, scope: !31)
+!31 = distinct !DILexicalBlock(scope: !32, file: !1, line: 10, column: 5)
+!32 = distinct !DILexicalBlock(scope: !23, file: !1, line: 10, column: 5)
+!33 = !DILocation(line: 10, column: 19, scope: !31)
+!34 = !DILocation(line: 10, column: 5, scope: !32)
+!35 = !DILocation(line: 11, column: 19, scope: !31)
+!36 = !DILocation(line: 11, column: 7, scope: !31)
+!37 = !DILocation(line: 10, column: 25, scope: !31)
+!38 = distinct !{!38, !34, !39}
+!39 = !DILocation(line: 11, column: 23, scope: !32)
+!40 = !DILocation(line: 13, column: 1, scope: !16)