1 ; RUN: opt < %s -instsimplify -S | FileCheck %s 2 3 ; PR8862 4 5 ; CHECK-LABEL: @shift1( 6 ; CHECK: ret i32 %A 7 define i32 @shift1(i32 %A, i32 %B) { 8 %C = lshr exact i32 %A, %B 9 %D = shl nuw i32 %C, %B 10 ret i32 %D 11 } 12 13 ; CHECK-LABEL: @shift2( 14 ; CHECK: lshr 15 ; CHECK: ret i32 %D 16 define i32 @shift2(i32 %A, i32 %B) { 17 %C = lshr i32 %A, %B 18 %D = shl nuw i32 %C, %B 19 ret i32 %D 20 } 21 22 ; CHECK-LABEL: @shift3( 23 ; CHECK: ret i32 %A 24 define i32 @shift3(i32 %A, i32 %B) { 25 %C = ashr exact i32 %A, %B 26 %D = shl nuw i32 %C, %B 27 ret i32 %D 28 } 29 30 ; CHECK-LABEL: @shift4( 31 ; CHECK: ret i32 %A 32 define i32 @shift4(i32 %A, i32 %B) { 33 %C = shl nuw i32 %A, %B 34 %D = lshr i32 %C, %B 35 ret i32 %D 36 } 37 38 ; CHECK-LABEL: @shift5( 39 ; CHECK: ret i32 %A 40 define i32 @shift5(i32 %A, i32 %B) { 41 %C = shl nsw i32 %A, %B 42 %D = ashr i32 %C, %B 43 ret i32 %D 44 } 45 46 ; CHECK-LABEL: @div1( 47 ; CHECK: ret i32 0 48 define i32 @div1(i32 %V) { 49 %A = udiv i32 %V, -2147483648 50 %B = udiv i32 %A, -2147483648 51 ret i32 %B 52 } 53 54 ; CHECK-LABEL: @div2( 55 ; CHECK-NOT: ret i32 0 56 define i32 @div2(i32 %V) { 57 %A = sdiv i32 %V, -1 58 %B = sdiv i32 %A, -2147483648 59 ret i32 %B 60 } 61
