1 ; RUN: opt < %s -S -early-cse | FileCheck %s 2 3 4 ; CHECK-LABEL: @test1( 5 define void @test1(i8 %V, i32 *%P) { 6 %A = bitcast i64 42 to double ;; dead 7 %B = add i32 4, 19 ;; constant folds 8 store i32 %B, i32* %P 9 ; CHECK-NEXT: store i32 23, i32* %P 10 11 %C = zext i8 %V to i32 12 %D = zext i8 %V to i32 ;; CSE 13 store volatile i32 %C, i32* %P 14 store volatile i32 %D, i32* %P 15 ; CHECK-NEXT: %C = zext i8 %V to i32 16 ; CHECK-NEXT: store volatile i32 %C 17 ; CHECK-NEXT: store volatile i32 %C 18 19 %E = add i32 %C, %C 20 %F = add i32 %C, %C 21 store volatile i32 %E, i32* %P 22 store volatile i32 %F, i32* %P 23 ; CHECK-NEXT: %E = add i32 %C, %C 24 ; CHECK-NEXT: store volatile i32 %E 25 ; CHECK-NEXT: store volatile i32 %E 26 27 %G = add nuw i32 %C, %C ;; not a CSE with E 28 store volatile i32 %G, i32* %P 29 ; CHECK-NEXT: %G = add nuw i32 %C, %C 30 ; CHECK-NEXT: store volatile i32 %G 31 ret void 32 } 33 34 35 ;; Simple load value numbering. 36 ; CHECK-LABEL: @test2( 37 define i32 @test2(i32 *%P) { 38 %V1 = load i32* %P 39 %V2 = load i32* %P 40 %Diff = sub i32 %V1, %V2 41 ret i32 %Diff 42 ; CHECK: ret i32 0 43 } 44 45 ;; Cross block load value numbering. 46 ; CHECK-LABEL: @test3( 47 define i32 @test3(i32 *%P, i1 %Cond) { 48 %V1 = load i32* %P 49 br i1 %Cond, label %T, label %F 50 T: 51 store i32 4, i32* %P 52 ret i32 42 53 F: 54 %V2 = load i32* %P 55 %Diff = sub i32 %V1, %V2 56 ret i32 %Diff 57 ; CHECK: F: 58 ; CHECK: ret i32 0 59 } 60 61 ;; Cross block load value numbering stops when stores happen. 62 ; CHECK-LABEL: @test4( 63 define i32 @test4(i32 *%P, i1 %Cond) { 64 %V1 = load i32* %P 65 br i1 %Cond, label %T, label %F 66 T: 67 ret i32 42 68 F: 69 ; Clobbers V1 70 store i32 42, i32* %P 71 72 %V2 = load i32* %P 73 %Diff = sub i32 %V1, %V2 74 ret i32 %Diff 75 ; CHECK: F: 76 ; CHECK: ret i32 %Diff 77 } 78 79 declare i32 @func(i32 *%P) readonly 80 81 ;; Simple call CSE'ing. 82 ; CHECK-LABEL: @test5( 83 define i32 @test5(i32 *%P) { 84 %V1 = call i32 @func(i32* %P) 85 %V2 = call i32 @func(i32* %P) 86 %Diff = sub i32 %V1, %V2 87 ret i32 %Diff 88 ; CHECK: ret i32 0 89 } 90 91 ;; Trivial Store->load forwarding 92 ; CHECK-LABEL: @test6( 93 define i32 @test6(i32 *%P) { 94 store i32 42, i32* %P 95 %V1 = load i32* %P 96 ret i32 %V1 97 ; CHECK: ret i32 42 98 } 99 100 ;; Trivial dead store elimination. 101 ; CHECK-LABEL: @test7( 102 define void @test7(i32 *%P) { 103 store i32 42, i32* %P 104 store i32 45, i32* %P 105 ret void 106 ; CHECK-NEXT: store i32 45 107 ; CHECK-NEXT: ret void 108 } 109 110 ;; Readnone functions aren't invalidated by stores. 111 ; CHECK-LABEL: @test8( 112 define i32 @test8(i32 *%P) { 113 %V1 = call i32 @func(i32* %P) readnone 114 store i32 4, i32* %P 115 %V2 = call i32 @func(i32* %P) readnone 116 %Diff = sub i32 %V1, %V2 117 ret i32 %Diff 118 ; CHECK: ret i32 0 119 } 120 121 122
