[llvm] a4e2a51 - [InstSimplify] Add (~A & B) | ~(A | B) --> ~A

[Dávid Bolvanský via llvm-commits]

And - yes, I can improve the comments (it works well when swapped - not is and’s op0)

Or - yes,  but “and” is always op0. (Complexivity canonicalization).



> Dňa 16. 1. 2021 o 16:01 užívateľ Roman Lebedev <lebedev.ri at gmail.com> napísal:
> 
> On Sat, Jan 16, 2021 at 5:54 PM Dávid Bolvanský via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>> 
>> 
>> Author: Dávid Bolvanský
>> Date: 2021-01-16T15:43:34+01:00
>> New Revision: a4e2a5145a29af678139f33e94ab3df0fc973e59
>> 
>> URL: https://github.com/llvm/llvm-project/commit/a4e2a5145a29af678139f33e94ab3df0fc973e59
>> DIFF: https://github.com/llvm/llvm-project/commit/a4e2a5145a29af678139f33e94ab3df0fc973e59.diff
>> 
>> LOG: [InstSimplify] Add (~A & B) | ~(A | B) --> ~A
>> 
>> Added:
>> 
>> 
>> Modified:
>>    llvm/lib/Analysis/InstructionSimplify.cpp
>>    llvm/test/Transforms/InstSimplify/or.ll
>> 
>> Removed:
>> 
>> 
>> 
>> ################################################################################
>> diff  --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
>> index 2ae4228495e3..6266e922f8c9 100644
>> --- a/llvm/lib/Analysis/InstructionSimplify.cpp
>> +++ b/llvm/lib/Analysis/InstructionSimplify.cpp
>> @@ -2262,6 +2262,12 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
>>        match(Op0, m_c_Xor(m_Not(m_Specific(A)), m_Specific(B)))))
>>     return Op0;
>> 
>> +  // (~A & B) | ~(A | B) --> ~A
>> +  // (~A & B) | ~(B | A) --> ~A
> Are the 'and' and outer 'or' not commutative?
> 
>> +  if (match(Op0, m_And(m_Not(m_Value(A)), m_Value(B))) &&
>> +      match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B)))))
>> +    return cast<BinaryOperator>(Op0)->getOperand(0);
>> +
>>   if (Value *V = simplifyAndOrOfCmps(Q, Op0, Op1, false))
>>     return V;
>> 
>> 
>> diff  --git a/llvm/test/Transforms/InstSimplify/or.ll b/llvm/test/Transforms/InstSimplify/or.ll
>> index e8284264c612..7e7361d12395 100644
>> --- a/llvm/test/Transforms/InstSimplify/or.ll
>> +++ b/llvm/test/Transforms/InstSimplify/or.ll
>> @@ -301,3 +301,97 @@ define i32 @poison(i32 %x) {
>>   %v = or i32 %x, poison
>>   ret i32 %v
>> }
>> +
>> +declare void @use(i32)
>> +
>> +define i32 @and_or_not_or(i32 %A, i32 %B) {
>> +; CHECK-LABEL: @and_or_not_or(
>> +; CHECK-NEXT:    [[I:%.*]] = xor i32 [[B:%.*]], -1
>> +; CHECK-NEXT:    ret i32 [[I]]
>> +;
>> +  %i = xor i32 %B, -1
>> +  %i2 = and i32 %i, %A
>> +  %i3 = or i32 %B, %A
>> +  %i4 = xor i32 %i3, -1
>> +  %i5 = or i32 %i2, %i4
>> +  ret i32 %i5
>> +}
>> +
>> +define i32 @and_or_not_or2(i32 %A, i32 %B) {
>> +; CHECK-LABEL: @and_or_not_or2(
>> +; CHECK-NEXT:    [[I:%.*]] = xor i32 [[A:%.*]], -1
>> +; CHECK-NEXT:    ret i32 [[I]]
>> +;
>> +  %i = xor i32 %A, -1
>> +  %i2 = and i32 %i, %B
>> +  %i3 = or i32 %B, %A
>> +  %i4 = xor i32 %i3, -1
>> +  %i5 = or i32 %i2, %i4
>> +  ret i32 %i5
>> +}
>> +
>> +define <4 x i32> @and_or_not_or3_vec(<4 x i32> %A, <4 x i32> %B) {
>> +; CHECK-LABEL: @and_or_not_or3_vec(
>> +; CHECK-NEXT:    [[I:%.*]] = xor <4 x i32> [[A:%.*]], <i32 -1, i32 -1, i32 -1, i32 -1>
>> +; CHECK-NEXT:    ret <4 x i32> [[I]]
>> +;
>> +  %i = xor <4 x i32> %A, <i32 -1, i32 -1, i32 -1, i32 -1>
>> +  %i2 = and <4 x i32> %i, %B
>> +  %i3 = or <4 x i32> %B, %A
>> +  %i4 = xor <4 x i32> %i3, <i32 -1, i32 -1, i32 -1, i32 -1>
>> +  %i5 = or <4 x i32> %i2, %i4
>> +  ret <4 x i32> %i5
>> +}
>> +
>> +define i32 @and_or_not_or4_use(i32 %A, i32 %B) {
>> +; CHECK-LABEL: @and_or_not_or4_use(
>> +; CHECK-NEXT:    [[I:%.*]] = xor i32 [[A:%.*]], -1
>> +; CHECK-NEXT:    [[I2:%.*]] = and i32 [[I]], [[B:%.*]]
>> +; CHECK-NEXT:    tail call void @use(i32 [[I2]])
>> +; CHECK-NEXT:    ret i32 [[I]]
>> +;
>> +  %i = xor i32 %A, -1
>> +  %i2 = and i32 %i, %B
>> +  tail call void @use(i32 %i2)
>> +  %i3 = or i32 %B, %A
>> +  %i4 = xor i32 %i3, -1
>> +  %i5 = or i32 %i2, %i4
>> +  ret i32 %i5
>> +}
>> +
>> +define i32 @and_or_not_or4_use2(i32 %A, i32 %B) {
>> +; CHECK-LABEL: @and_or_not_or4_use2(
>> +; CHECK-NEXT:    [[I:%.*]] = or i32 [[B:%.*]], [[A:%.*]]
>> +; CHECK-NEXT:    [[I2:%.*]] = xor i32 [[I]], -1
>> +; CHECK-NEXT:    tail call void @use(i32 [[I2]])
>> +; CHECK-NEXT:    [[I3:%.*]] = xor i32 [[A]], -1
>> +; CHECK-NEXT:    ret i32 [[I3]]
>> +;
>> +  %i = or i32 %B, %A
>> +  %i2 = xor i32 %i, -1
>> +  tail call void @use(i32 %i2)
>> +  %i3 = xor i32 %A, -1
>> +  %i4 = and i32 %i3, %B
>> +  %i5 = or i32 %i4, %i2
>> +  ret i32 %i5
>> +}
>> +
>> +define i32 @and_or_not_or4_use3(i32 %A, i32 %B) {
>> +; CHECK-LABEL: @and_or_not_or4_use3(
>> +; CHECK-NEXT:    [[I:%.*]] = or i32 [[B:%.*]], [[A:%.*]]
>> +; CHECK-NEXT:    [[I2:%.*]] = xor i32 [[I]], -1
>> +; CHECK-NEXT:    tail call void @use(i32 [[I2]])
>> +; CHECK-NEXT:    [[I3:%.*]] = xor i32 [[A]], -1
>> +; CHECK-NEXT:    [[I4:%.*]] = and i32 [[I3]], [[B]]
>> +; CHECK-NEXT:    tail call void @use(i32 [[I4]])
>> +; CHECK-NEXT:    ret i32 [[I3]]
>> +;
>> +  %i = or i32 %B, %A
>> +  %i2 = xor i32 %i, -1
>> +  tail call void @use(i32 %i2)
>> +  %i3 = xor i32 %A, -1
>> +  %i4 = and i32 %i3, %B
>> +  tail call void @use(i32 %i4)
>> +  %i5 = or i32 %i4, %i2
>> +  ret i32 %i5
>> +}
>> 
>> 
>> 
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