1 ; RUN: opt < %s -instsimplify -S | FileCheck %s 2 3 ; PR8862 4 5 define i32 @shift1(i32 %A, i32 %B) { 6 ; CHECK-LABEL: @shift1( 7 ; CHECK-NEXT: ret i32 %A 8 ; 9 %C = lshr exact i32 %A, %B 10 %D = shl nuw i32 %C, %B 11 ret i32 %D 12 } 13 14 define i32 @shift2(i32 %A, i32 %B) { 15 ; CHECK-LABEL: @shift2( 16 ; CHECK-NEXT: [[C:%.*]] = lshr i32 %A, %B 17 ; CHECK-NEXT: [[D:%.*]] = shl nuw i32 [[C]], %B 18 ; CHECK-NEXT: ret i32 [[D]] 19 ; 20 %C = lshr i32 %A, %B 21 %D = shl nuw i32 %C, %B 22 ret i32 %D 23 } 24 25 define i32 @shift3(i32 %A, i32 %B) { 26 ; CHECK-LABEL: @shift3( 27 ; CHECK-NEXT: ret i32 %A 28 ; 29 %C = ashr exact i32 %A, %B 30 %D = shl nuw i32 %C, %B 31 ret i32 %D 32 } 33 34 define i32 @shift4(i32 %A, i32 %B) { 35 ; CHECK-LABEL: @shift4( 36 ; CHECK-NEXT: ret i32 %A 37 ; 38 %C = shl nuw i32 %A, %B 39 %D = lshr i32 %C, %B 40 ret i32 %D 41 } 42 43 define i32 @shift5(i32 %A, i32 %B) { 44 ; CHECK-LABEL: @shift5( 45 ; CHECK-NEXT: ret i32 %A 46 ; 47 %C = shl nsw i32 %A, %B 48 %D = ashr i32 %C, %B 49 ret i32 %D 50 } 51 52 define i32 @div1(i32 %V) { 53 ; CHECK-LABEL: @div1( 54 ; CHECK-NEXT: ret i32 0 55 ; 56 %A = udiv i32 %V, -2147483648 57 %B = udiv i32 %A, -2147483648 58 ret i32 %B 59 } 60 61 define i32 @div2(i32 %V) { 62 ; CHECK-LABEL: @div2( 63 ; CHECK-NEXT: ret i32 0 64 ; 65 %A = sdiv i32 %V, -1 66 %B = sdiv i32 %A, -2147483648 67 ret i32 %B 68 } 69 70
