; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -S < %s -instcombine | FileCheck %s ; Fold ; (X & C) - X ; to ; - (X & ~C) ; ; This allows us to possibly hoist said negation further out, ; and decreases use count of X. ; https://bugs.llvm.org/show_bug.cgi?id=44427 ; Base tests define i8 @t0(i8 %x) { ; CHECK-LABEL: @t0( ; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X:%.*]], -43 ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 0, [[TMP1]] ; CHECK-NEXT: ret i8 [[NEGBIAS]] ; %unbiasedx = and i8 %x, 42 %negbias = sub i8 %unbiasedx, %x ret i8 %negbias } define <2 x i8> @t1_vec(<2 x i8> %x) { ; CHECK-LABEL: @t1_vec( ; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]] ; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]] ; %unbiasedx = and <2 x i8> %x, %negbias = sub <2 x i8> %unbiasedx, %x ret <2 x i8> %negbias } define <2 x i8> @t2_vec_undef(<2 x i8> %x) { ; CHECK-LABEL: @t2_vec_undef( ; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]] ; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]] ; %unbiasedx = and <2 x i8> %x, %negbias = sub <2 x i8> %unbiasedx, %x ret <2 x i8> %negbias } define <2 x i8> @t3_vec_nonsplat(<2 x i8> %x) { ; CHECK-LABEL: @t3_vec_nonsplat( ; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]] ; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]] ; %unbiasedx = and <2 x i8> %x, %negbias = sub <2 x i8> %unbiasedx, %x ret <2 x i8> %negbias } ; Extra uses always prevent fold declare void @use8(i8) define i8 @n4_extrause(i8 %x) { ; CHECK-LABEL: @n4_extrause( ; CHECK-NEXT: [[UNBIASEDX:%.*]] = and i8 [[X:%.*]], 42 ; CHECK-NEXT: call void @use8(i8 [[UNBIASEDX]]) ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 [[UNBIASEDX]], [[X]] ; CHECK-NEXT: ret i8 [[NEGBIAS]] ; %unbiasedx = and i8 %x, 42 call void @use8(i8 %unbiasedx) %negbias = sub i8 %unbiasedx, %x ret i8 %negbias } ; Negative tests define i8 @n5(i8 %x) { ; CHECK-LABEL: @n5( ; CHECK-NEXT: [[NEGBIAS:%.*]] = and i8 [[X:%.*]], -43 ; CHECK-NEXT: ret i8 [[NEGBIAS]] ; %unbiasedx = and i8 %x, 42 %negbias = sub i8 %x, %unbiasedx ; wrong order ret i8 %negbias } define i8 @n6(i8 %x0, i8 %x1) { ; CHECK-LABEL: @n6( ; CHECK-NEXT: [[UNBIASEDX:%.*]] = and i8 [[X1:%.*]], 42 ; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 [[UNBIASEDX]], [[X0:%.*]] ; CHECK-NEXT: ret i8 [[NEGBIAS]] ; %unbiasedx = and i8 %x1, 42 ; not %x0 %negbias = sub i8 %unbiasedx, %x0 ; not %x1 ret i8 %negbias }