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

35 lines
938 B
LLVM

; 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]]
}