Author: Dávid Bolvanský Date: 2020-12-31T15:04:32+01:00 New Revision: ae69fa9b9f65f59cc0ca8c47f23748a53c8dbdc5
URL: https://github.com/llvm/llvm-project/commit/ae69fa9b9f65f59cc0ca8c47f23748a53c8dbdc5 DIFF: https://github.com/llvm/llvm-project/commit/ae69fa9b9f65f59cc0ca8c47f23748a53c8dbdc5.diff LOG: [InstCombine] Transform (A + B) - (A & B) to A | B (PR48604) define i32 @src(i32 %x, i32 %y) { %0: %a = add i32 %x, %y %o = and i32 %x, %y %r = sub i32 %a, %o ret i32 %r } => define i32 @tgt(i32 %x, i32 %y) { %0: %b = or i32 %x, %y ret i32 %b } Transformation seems to be correct! https://alive2.llvm.org/ce/z/2fhW6r Added: Modified: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp llvm/test/Transforms/InstCombine/sub.ll Removed: ################################################################################ diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index be145615a241..bacb8689892a 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1881,6 +1881,14 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { return BinaryOperator::CreateAnd(A, B); } + // (sub (add A, B) (and A, B)) --> (or A, B) + { + Value *A, *B; + if (match(Op0, m_Add(m_Value(A), m_Value(B))) && + match(Op1, m_c_And(m_Specific(A), m_Specific(B)))) + return BinaryOperator::CreateOr(A, B); + } + // (sub (and A, B) (or A, B)) --> neg (xor A, B) { Value *A, *B; diff --git a/llvm/test/Transforms/InstCombine/sub.ll b/llvm/test/Transforms/InstCombine/sub.ll index aaac3f23f71f..649d2e8c2848 100644 --- a/llvm/test/Transforms/InstCombine/sub.ll +++ b/llvm/test/Transforms/InstCombine/sub.ll @@ -1621,9 +1621,7 @@ define <2 x i8> @and_vec(<2 x i8> %X, <2 x i8> %Y) { define i32 @or_test(i32 %x, i32 %y) { ; CHECK-LABEL: @or_test( -; CHECK-NEXT: [[A:%.*]] = add i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[B:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[B]] +; CHECK-NEXT: [[R:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %x, %y @@ -1634,9 +1632,7 @@ define i32 @or_test(i32 %x, i32 %y) { define i32 @or_test2(i32 %x, i32 %y) { ; CHECK-LABEL: @or_test2( -; CHECK-NEXT: [[A:%.*]] = add i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[B:%.*]] = and i32 [[Y]], [[X]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[B]] +; CHECK-NEXT: [[R:%.*]] = or i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %x, %y @@ -1647,9 +1643,7 @@ define i32 @or_test2(i32 %x, i32 %y) { define i32 @or_test3(i32 %x, i32 %y) { ; CHECK-LABEL: @or_test3( -; CHECK-NEXT: [[A:%.*]] = add i32 [[Y:%.*]], [[X:%.*]] -; CHECK-NEXT: [[B:%.*]] = and i32 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[B]] +; CHECK-NEXT: [[R:%.*]] = or i32 [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %y, %x @@ -1660,9 +1654,7 @@ define i32 @or_test3(i32 %x, i32 %y) { define <2 x i8> @or_vec(<2 x i8> %X, <2 x i8> %Y) { ; CHECK-LABEL: @or_vec( -; CHECK-NEXT: [[A:%.*]] = add <2 x i8> [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[B:%.*]] = and <2 x i8> [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub <2 x i8> [[A]], [[B]] +; CHECK-NEXT: [[R:%.*]] = or <2 x i8> [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: ret <2 x i8> [[R]] ; %a = add <2 x i8> %X, %Y _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits