| ; 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 |
| } |