3 files changed, 216 insertions, 4 deletions

diff --git a/test/Transforms/DeadStoreElimination/calloc-store.ll b/test/Transforms/DeadStoreElimination/calloc-store.ll
new file mode 100644
index 000000000000..daba61332065
--- /dev/null
+++ b/test/Transforms/DeadStoreElimination/calloc-store.ll
@@ -0,0 +1,65 @@
+; RUN: opt < %s -basicaa -dse -S | FileCheck %s
+
+declare noalias i8* @calloc(i64, i64)
+
+define i32* @test1() {
+; CHECK-LABEL: test1
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  %2 = bitcast i8* %1 to i32*
+  ; This store is dead and should be removed
+  store i32 0, i32* %2, align 4
+; CHECK-NOT: store i32 0, i32* %2, align 4
+  ret i32* %2
+}
+
+define i32* @test2() {
+; CHECK-LABEL: test2
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  %2 = bitcast i8* %1 to i32*
+  %3 = getelementptr i32, i32* %2, i32 5
+  store i32 0, i32* %3, align 4
+; CHECK-NOT: store i32 0, i32* %2, align 4
+  ret i32* %2
+}
+
+define i32* @test3(i32 *%arg) {
+; CHECK-LABEL: test3
+  store i32 0, i32* %arg, align 4
+; CHECK: store i32 0, i32* %arg, align 4
+  ret i32* %arg
+}
+
+declare void @clobber_memory(i8*)
+define i8* @test4() {
+; CHECK-LABEL: test4
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  call void @clobber_memory(i8* %1)
+  store i8 0, i8* %1, align 4
+; CHECK: store i8 0, i8* %1, align 4
+  ret i8* %1
+}
+
+define i32* @test5() {
+; CHECK-LABEL: test5
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  %2 = bitcast i8* %1 to i32*
+  store volatile i32 0, i32* %2, align 4
+; CHECK: store volatile i32 0, i32* %2, align 4
+  ret i32* %2
+}
+
+define i8* @test6() {
+; CHECK-LABEL: test6
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  store i8 5, i8* %1, align 4
+; CHECK: store i8 5, i8* %1, align 4
+  ret i8* %1
+}
+
+define i8* @test7(i8 %arg) {
+; CHECK-LABEL: test7
+  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
+  store i8 %arg, i8* %1, align 4
+; CHECK: store i8 %arg, i8* %1, align 4
+  ret i8* %1
+}
diff --git a/test/Transforms/DeadStoreElimination/inst-limits.ll b/test/Transforms/DeadStoreElimination/inst-limits.ll
index 54e41c8b413b..5848ab89bc88 100644
--- a/test/Transforms/DeadStoreElimination/inst-limits.ll
+++ b/test/Transforms/DeadStoreElimination/inst-limits.ll
@@ -9,7 +9,7 @@ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 @x = global i32 0, align 4
 
 ; Function Attrs: nounwind
-define i32 @test_within_limit() {
+define i32 @test_within_limit() !dbg !4 {
 entry:
   ; The first store; later there is a second store to the same location,
   ; so this store should be optimized away by DSE.
@@ -245,17 +245,17 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!11, !13}
 
-!0 = !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.4", isOptimized: true, emissionKind: 0, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.4", isOptimized: true, emissionKind: 0, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
 !1 = !DIFile(filename: "test.c", directory: "/home/tmp")
 !2 = !{}
 !3 = !{!4}
-!4 = !DISubprogram(name: "test_within_limit", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, function: i32 ()* @test_within_limit, variables: !2)
+!4 = distinct !DISubprogram(name: "test_within_limit", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "test.c", directory: "/home/tmp")
 !6 = !DISubroutineType(types: !7)
 !7 = !{!8}
 !8 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 !9 = !{!10}
-!10 = !DILocalVariable(tag: DW_TAG_auto_variable, name: "x", scope: !4, type: !8)
+!10 = !DILocalVariable(name: "x", scope: !4, type: !8)
 !11 = !{i32 2, !"Dwarf Version", i32 4}
 !12 = !{i32* undef}
 
diff --git a/test/Transforms/DeadStoreElimination/simple.ll b/test/Transforms/DeadStoreElimination/simple.ll
index 2ffe0539098e..4f6221db2454 100644
--- a/test/Transforms/DeadStoreElimination/simple.ll
+++ b/test/Transforms/DeadStoreElimination/simple.ll
@@ -350,3 +350,150 @@ define i8* @test25(i8* %p) nounwind {
   store i8 %tmp, i8* %p.4, align 1
   ret i8* %q
 }
+
+; Remove redundant store if loaded value is in another block.
+; CHECK-LABEL: @test26(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test26(i1 %c, i32* %p) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  store i32 %v, i32* %p, align 4
+  br label %bb3
+bb3:
+  ret i32 0
+}
+
+; Remove redundant store if loaded value is in another block.
+; CHECK-LABEL: @test27(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test27(i1 %c, i32* %p) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Don't remove redundant store because of may-aliased store.
+; CHECK-LABEL: @test28(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test28(i1 %c, i32* %p, i32* %p2, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+
+  ; Might overwrite value at %p
+  store i32 %i, i32* %p2, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Don't remove redundant store because of may-aliased store.
+; CHECK-LABEL: @test29(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test29(i1 %c, i32* %p, i32* %p2, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  ; Might overwrite value at %p
+  store i32 %i, i32* %p2, align 4
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+declare void @unknown_func()
+
+; Don't remove redundant store because of unknown call.
+; CHECK-LABEL: @test30(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test30(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  ; Might overwrite value at %p
+  call void @unknown_func()
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Remove redundant store if loaded value is in another block inside a loop.
+; CHECK-LABEL: @test31(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test31(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br label %bb1
+bb1:
+  store i32 %v, i32* %p, align 4
+  br i1 undef, label %bb1, label %bb2
+bb2:
+  ret i32 0
+}
+
+; Don't remove redundant store in a loop with a may-alias store.
+; CHECK-LABEL: @test32(
+; CHECK: bb1:
+; CHECK-NEXT: store i32 %v
+; CHECK-NEXT: call void @unknown_func
+define i32 @test32(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br label %bb1
+bb1:
+  store i32 %v, i32* %p, align 4
+  ; Might read and overwrite value at %p
+  call void @unknown_func()
+  br i1 undef, label %bb1, label %bb2
+bb2:
+  ret i32 0
+}
+
+; Remove redundant store, which is in the lame loop as the load.
+; CHECK-LABEL: @test33(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test33(i1 %c, i32* %p, i32 %i) {
+entry:
+  br label %bb1
+bb1:
+  %v = load i32, i32* %p, align 4
+  br label %bb2
+bb2:
+  store i32 %v, i32* %p, align 4
+  ; Might read and overwrite value at %p, but doesn't matter.
+  call void @unknown_func()
+  br i1 undef, label %bb1, label %bb3
+bb3:
+  ret i32 0
+}
+