llvm-mirror/test/Transforms/InstCombine/demorgan-zext.ll

; RUN: opt < %s -instcombine -S | FileCheck %s

; PR22723: Recognize De Morgan's Laws when obfuscated by zexts.

define i32 @demorgan_or(i1 %X, i1 %Y) {
  %zextX = zext i1 %X to i32
  %zextY = zext i1 %Y to i32
  %notX  = xor i32 %zextX, 1
  %notY  = xor i32 %zextY, 1
  %or    = or i32 %notX, %notY
  ret i32 %or

; CHECK-LABEL: demorgan_or(
; CHECK-NEXT:  %[[AND:.*]] = and i1 %X, %Y
; CHECK-NEXT:  %[[ZEXT:.*]] = zext i1 %[[AND]] to i32
; CHECK-NEXT:  %[[XOR:.*]] = xor i32 %[[ZEXT]], 1
; CHECK-NEXT:  ret i32 %[[XOR]]
}

define i32 @demorgan_and(i1 %X, i1 %Y) {
  %zextX = zext i1 %X to i32
  %zextY = zext i1 %Y to i32
  %notX  = xor i32 %zextX, 1
  %notY  = xor i32 %zextY, 1
  %and   = and i32 %notX, %notY
  ret i32 %and

; CHECK-LABEL: demorgan_and(
; CHECK-NEXT:  %[[OR:.*]] = or i1 %X, %Y
; CHECK-NEXT:  %[[ZEXT:.*]] = zext i1 %[[OR]] to i32
; CHECK-NEXT:  %[[XOR:.*]] = xor i32 %[[ZEXT]], 1
; CHECK-NEXT:  ret i32 %[[XOR]]
}