| ; 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.lifetime.start(i64, i8* nocapture) nounwind |
| declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind |
| declare void @llvm.memset.i8(i8*, i8, i8, i32) |
| |
| define void @test1() { |
| ; CHECK: @test1 |
| %A = alloca i8 |
| |
| store i8 0, i8* %A ;; Written to by memset |
| call void @llvm.lifetime.end(i64 1, i8* %A) |
| ; CHECK: lifetime.end |
| |
| call void @llvm.memset.i8(i8* %A, i8 0, i8 -1, i32 0) |
| ; CHECK-NOT: memset |
| |
| ret void |
| ; CHECK: ret void |
| } |
| |
| define void @test2(i32* %P) { |
| ; CHECK: test2 |
| %Q = getelementptr i32* %P, i32 1 |
| %R = bitcast i32* %Q to i8* |
| call void @llvm.lifetime.start(i64 4, i8* %R) |
| ; CHECK: lifetime.start |
| store i32 0, i32* %Q ;; This store is dead. |
| ; CHECK-NOT: store |
| call void @llvm.lifetime.end(i64 4, i8* %R) |
| ; CHECK: lifetime.end |
| ret void |
| } |
| |
| |
