SimplifyAllocas: search through more bitcasts to find alloca for llvm.dbg.declare.

test/Transforms/NaCl/simplify-allocas.ll

 ; RUN: opt < %s -simplify-allocas -S | FileCheck %s
 
 target datalayout = "p:32:32:32"
 
 %struct = type { i32, i32 }
 
 declare void @receive_alloca(%struct* %ptr)
 declare void @receive_vector_alloca(<4 x i32>* %ptr)
 
 define void @alloca_fixed() {
@@ skipping 120 matching lines @@
 }
 ; CHECK-LABEL: define void @dyn_inst_alloca_array_zext(i8 %a)
 ; CHECK-NEXT:    %b = add i8 1, %a
 ; CHECK-NEXT:    zext i8 %b to i32
 ; CHECK-NEXT:    mul i32 4,
 ; CHECK-NEXT:    %c = alloca i8, i32
 
 declare void @llvm.dbg.declare(metadata, metadata, metadata)
 define void @debug_declare() {
   %var = alloca i32
-  call void @llvm.dbg.declare(metadata i32* %var, metadata !11, metadata !12), !dbg !13
+  call void @llvm.dbg.declare(metadata i32* %var, metadata !12, metadata !13), !dbg !14
   unreachable
 }
 ; Ensure that the first arg to dbg.declare points to the alloca, not the bitcast
 ; CHECK-LABEL: define void @debug_declare
 ; CHECK-NEXT: %var = alloca i8, i32 4
-; CHECK: call void @llvm.dbg.declare(metadata i8* %var, metadata !11, metadata !12), !dbg !13
+; CHECK: call void @llvm.dbg.declare(metadata i8* %var, metadata !12, metadata !13), !dbg !14
+
+define void @debug_declare_morecasts() {
+  %var = alloca i32, i32 2, align 8
+  %other_bc = bitcast i32* %var to i64*
+  %other_bc2 = bitcast i64* %other_bc to i16*
+  call void @llvm.dbg.declare(metadata i16* %other_bc2, metadata !15, metadata !13), !dbg !16
+  unreachable
+}
+; Ensure that the first arg to dbg.declare points to the alloca, not bitcasts
+; CHECK-LABEL: define void @debug_declare_morecasts
+; CHECK-NEXT: %var = alloca i8, i32 8, align 8
+; CHECK: call void @llvm.dbg.declare(metadata i8* %var, metadata !15, metadata !13), !dbg !16
 
 !llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!8, !9}
-!llvm.ident = !{!10}
+!llvm.module.flags = !{!9, !10}
+!llvm.ident = !{!11}
 
 ; CHECK: !4 = !MDSubprogram(name: "debug_declare", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, function: void ()* @debug_declare, variables: !2)
 
 !0 = !MDCompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 235150) (llvm/trunk 235152)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
 !1 = !MDFile(filename: "foo.c", directory: "/s/llvm/cmakebuild")
 !2 = !{}
-!3 = !{!4}
+!3 = !{!4, !8}
 !4 = !MDSubprogram(name: "debug_declare", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, function: void ()* @debug_declare, variables: !2)
 !5 = !MDSubroutineType(types: !6)
 !6 = !{null, !7}
 !7 = !MDBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
-!8 = !{i32 2, !"Dwarf Version", i32 4}
-!9 = !{i32 2, !"Debug Info Version", i32 3}
-!10 = !{!"clang version 3.7.0 (trunk 235150) (llvm/trunk 235152)"}
-!11 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "val", arg: 1, scope: !4, file: !1, line: 1, type: !7)
-!12 = !MDExpression()
-!13 = !MDLocation(line: 1, column: 24, scope: !4)
+!8 = !MDSubprogram(name: "debug_declare_morecasts", scope: !1, file: !1, line: 8, type: !5, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, function: void ()* @debug_declare_morecasts, variables: !2)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{!"clang version 3.7.0 (trunk 235150) (llvm/trunk 235152)"}
+!12 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "val", arg: 1, scope: !4, file: !1, line: 1, type: !7)
+!13 = !MDExpression()
+!14 = !MDLocation(line: 1, column: 24, scope: !4)
+!15 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "var", arg: 1, scope: !8, file: !1, line: 9, type: !7)
+!16 = !MDLocation(line: 9, column: 24, scope: !8)