1*9880d681SAndroid Build Coastguard Worker; RUN: opt -S -instcombine < %s | FileCheck %s 2*9880d681SAndroid Build Coastguard Worker 3*9880d681SAndroid Build Coastguard Worker; https://llvm.org/bugs/show_bug.cgi?id=25900 4*9880d681SAndroid Build Coastguard Worker; An arithmetic shift right of a power of two is not a power 5*9880d681SAndroid Build Coastguard Worker; of two if the original value is the sign bit. Therefore, 6*9880d681SAndroid Build Coastguard Worker; we can't transform the sdiv into a udiv. 7*9880d681SAndroid Build Coastguard Worker 8*9880d681SAndroid Build Coastguard Workerdefine i32 @pr25900(i32 %d) { 9*9880d681SAndroid Build Coastguard Worker %and = and i32 %d, -2147483648 10*9880d681SAndroid Build Coastguard Worker; The next 3 lines prevent another fold from masking the bug. 11*9880d681SAndroid Build Coastguard Worker %ext = zext i32 %and to i64 12*9880d681SAndroid Build Coastguard Worker %or = or i64 %ext, 4294967296 13*9880d681SAndroid Build Coastguard Worker %trunc = trunc i64 %or to i32 14*9880d681SAndroid Build Coastguard Worker %ashr = ashr exact i32 %trunc, 31 15*9880d681SAndroid Build Coastguard Worker %div = sdiv i32 4, %ashr 16*9880d681SAndroid Build Coastguard Worker ret i32 %div 17*9880d681SAndroid Build Coastguard Worker 18*9880d681SAndroid Build Coastguard Worker; CHECK: sdiv 19*9880d681SAndroid Build Coastguard Worker} 20*9880d681SAndroid Build Coastguard Worker 21