; RUN: opt < %s -basicaa -dse -S | FileCheck %s
target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+declare void @llvm.memset.i64(i8*, i8, i64, i32)
+declare void @llvm.memcpy.i64(i8*, i8*, i64, i32)
+declare i8* @llvm.init.trampoline(i8*, i8*, i8*)
+
define void @test1(i32* %Q, i32* %P) {
%DEAD = load i32* %Q
store i32 %DEAD, i32* %P
; CHECK-NEXT: ret void
}
-declare void @llvm.memset.i64(i8*, i8, i64, i32)
-declare void @llvm.memcpy.i64(i8*, i8*, i64, i32)
-
; Should delete store of 10 even though memset is a may-store to P (P and Q may
; alias).
define void @test6(i32 *%p, i8 *%q) {
; DSE should delete the dead trampoline.
-declare i8* @llvm.init.trampoline(i8*, i8*, i8*)
declare void @test11f()
define void @test11() {
; CHECK: @test11
declare noalias i8* @malloc(i32)
+
+
+define void @test14(i32* %Q) {
+ %P = alloca i32
+ %DEAD = load i32* %Q
+ store i32 %DEAD, i32* %P
+ ret void
+
+; CHECK: @test14
+; CHECK-NEXT: ret void
+}
+
+
+; PR8701
+
+;; Fully dead overwrite of memcpy.
+define void @test15(i8* %P, i8* %Q) nounwind ssp {
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1)
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1)
+ ret void
+; CHECK: @test15
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: ret
+}
+
+;; Full overwrite of smaller memcpy.
+define void @test16(i8* %P, i8* %Q) nounwind ssp {
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 8, i32 1)
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1)
+ ret void
+; CHECK: @test16
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: ret
+}
+
+;; Overwrite of memset by memcpy.
+define void @test17(i8* %P, i8* noalias %Q) nounwind ssp {
+ tail call void @llvm.memset.i64(i8* %P, i8 42, i64 8, i32 1)
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1)
+ ret void
+; CHECK: @test17
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: ret
+}
+
+; Should not delete the volatile memset.
+define void @test17v(i8* %P, i8* %Q) nounwind ssp {
+ tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true)
+ tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
+ ret void
+; CHECK: @test17v
+; CHECK-NEXT: call void @llvm.memset
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: ret
+}
+
+; PR8728
+; Do not delete instruction where possible situation is:
+; A = B
+; A = A
+define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp {
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1)
+ tail call void @llvm.memcpy.i64(i8* %P, i8* %R, i64 12, i32 1)
+ ret void
+; CHECK: @test18
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: ret
+}