1 ; Test that GCSE uses basicaa to do alias analysis, which is capable of 2 ; disambiguating some obvious cases. All loads should be removable in 3 ; this testcase. 4 5 ; RUN: opt < %s -basicaa -gvn -instcombine -dce -S | FileCheck %s 6 7 @A = global i32 7 8 @B = global i32 8 9 10 ; CHECK: define i32 @test() 11 ; CHECK-NEXT: store i32 123, i32* @B 12 ; CHECK-NEXT: ret i32 0 13 14 define i32 @test() { 15 %A1 = load i32* @A 16 17 store i32 123, i32* @B ; Store cannot alias @A 18 19 %A2 = load i32* @A 20 %X = sub i32 %A1, %A2 21 ret i32 %X 22 } 23 24 ; CHECK: define i32 @test2() 25 ; CHECK-NEXT: br label %Loop 26 ; CHECK: Loop: 27 ; CHECK-NEXT: store i32 0, i32* @B 28 ; CHECK-NEXT: br i1 true, label %out, label %Loop 29 ; CHECK: out: 30 ; CHECK-NEXT: ret i32 0 31 32 define i32 @test2() { 33 %A1 = load i32* @A 34 br label %Loop 35 Loop: 36 %AP = phi i32 [0, %0], [%X, %Loop] 37 store i32 %AP, i32* @B ; Store cannot alias @A 38 39 %A2 = load i32* @A 40 %X = sub i32 %A1, %A2 41 %c = icmp eq i32 %X, 0 42 br i1 %c, label %out, label %Loop 43 44 out: 45 ret i32 %X 46 } 47 48 declare void @external() 49 50 ; CHECK: define i32 @test3() 51 ; CHECK-NEXT: call void @external() 52 ; CHECK-NEXT: ret i32 7 53 54 define i32 @test3() { 55 %X = alloca i32 56 store i32 7, i32* %X 57 call void @external() 58 %V = load i32* %X 59 ret i32 %V 60 } 61 62
