; RUN: opt < %s -instcombine -S | FileCheck %s ; Remove an icmp by using its operand in the subsequent logic directly. define i8 @zext_or_icmp_icmp(i8 %a, i8 %b) { %mask = and i8 %a, 1 %toBool1 = icmp eq i8 %mask, 0 %toBool2 = icmp eq i8 %b, 0 %bothCond = or i1 %toBool1, %toBool2 %zext = zext i1 %bothCond to i8 ret i8 %zext ; CHECK-LABEL: zext_or_icmp_icmp( ; CHECK-NEXT: %mask = and i8 %a, 1 ; CHECK-NEXT: %toBool2 = icmp eq i8 %b, 0 ; CHECK-NEXT: %toBool22 = zext i1 %toBool2 to i8 ; CHECK-NEXT: %1 = xor i8 %mask, 1 ; CHECK-NEXT: %zext = or i8 %1, %toBool22 ; CHECK-NEXT: ret i8 %zext } ; Here, widening the or from i1 to i32 and removing one of the icmps would ; widen an undef value (created by the out-of-range shift), increasing the ; range of valid values for the return, so we can't do it. define i32 @dont_widen_undef() { entry: br label %block2 block1: br label %block2 block2: %m.011 = phi i32 [ 33, %entry ], [ 0, %block1 ] %cmp.i = icmp ugt i32 %m.011, 1 %m.1.op = lshr i32 1, %m.011 %sext.mask = and i32 %m.1.op, 65535 %cmp115 = icmp ne i32 %sext.mask, 0 %cmp1 = or i1 %cmp.i, %cmp115 %conv2 = zext i1 %cmp1 to i32 ret i32 %conv2 ; CHECK-LABEL: dont_widen_undef( ; CHECK: %m.011 = phi i32 [ 33, %entry ], [ 0, %block1 ] ; CHECK-NEXT: %cmp.i = icmp ugt i32 %m.011, 1 ; CHECK-NEXT: %m.1.op = lshr i32 1, %m.011 ; CHECK-NEXT: %sext.mask = and i32 %m.1.op, 65535 ; CHECK-NEXT: %cmp115 = icmp ne i32 %sext.mask, 0 ; CHECK-NEXT: %cmp1 = or i1 %cmp.i, %cmp115 ; CHECK-NEXT: %conv2 = zext i1 %cmp1 to i32 ; CHECK-NEXT: ret i32 %conv2 }