Author: Dávid Bolvanský Date: 2020-12-31T14:03:20+01:00 New Revision: 742ea77ca4c0ea10d8ccd160c7d7f4257d214ed0
URL: https://github.com/llvm/llvm-project/commit/742ea77ca4c0ea10d8ccd160c7d7f4257d214ed0 DIFF: https://github.com/llvm/llvm-project/commit/742ea77ca4c0ea10d8ccd160c7d7f4257d214ed0.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 = or i32 %x, %y %r = sub i32 %a, %o ret i32 %r } => define i32 @tgt(i32 %x, i32 %y) { %0: %b = and i32 %x, %y ret i32 %b } Transformation seems to be correct! https://alive2.llvm.org/ce/z/aQRh2j Added: Modified: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp llvm/test/Transforms/InstCombine/and.ll Removed: ################################################################################ diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index c20861f20f07..be145615a241 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1873,6 +1873,14 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { return BinaryOperator::CreateXor(A, B); } + // (sub (add A, B) (or A, B)) --> (and A, B) + { + Value *A, *B; + if (match(Op0, m_Add(m_Value(A), m_Value(B))) && + match(Op1, m_c_Or(m_Specific(A), m_Specific(B)))) + return BinaryOperator::CreateAnd(A, B); + } + // (sub (and A, B) (or A, B)) --> neg (xor A, B) { Value *A, *B; diff --git a/llvm/test/Transforms/InstCombine/and.ll b/llvm/test/Transforms/InstCombine/and.ll index 4f054c05889a..a3d5932ff140 100644 --- a/llvm/test/Transforms/InstCombine/and.ll +++ b/llvm/test/Transforms/InstCombine/and.ll @@ -1221,9 +1221,7 @@ define <2 x i8> @flip_masked_bit_nonuniform(<2 x i8> %A) { define i32 @and_test(i32 %x, i32 %y) { ; CHECK-LABEL: @and_test( -; CHECK-NEXT: [[A:%.*]] = add i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[O:%.*]] = or i32 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[O]] +; CHECK-NEXT: [[R:%.*]] = and i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %x, %y @@ -1234,9 +1232,7 @@ define i32 @and_test(i32 %x, i32 %y) { define i32 @and_test2(i32 %x, i32 %y) { ; CHECK-LABEL: @and_test2( -; CHECK-NEXT: [[A:%.*]] = add i32 [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[O:%.*]] = or i32 [[Y]], [[X]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[O]] +; CHECK-NEXT: [[R:%.*]] = and i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %x, %y @@ -1247,9 +1243,7 @@ define i32 @and_test2(i32 %x, i32 %y) { define i32 @and_test3(i32 %x, i32 %y) { ; CHECK-LABEL: @and_test3( -; CHECK-NEXT: [[A:%.*]] = add i32 [[Y:%.*]], [[X:%.*]] -; CHECK-NEXT: [[O:%.*]] = or i32 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub i32 [[A]], [[O]] +; CHECK-NEXT: [[R:%.*]] = and i32 [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: ret i32 [[R]] ; %a = add i32 %y, %x @@ -1261,9 +1255,7 @@ define i32 @and_test3(i32 %x, i32 %y) { define <2 x i8> @and_vec(<2 x i8> %X, <2 x i8> %Y) { ; CHECK-LABEL: @and_vec( -; CHECK-NEXT: [[A:%.*]] = add <2 x i8> [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[O:%.*]] = or <2 x i8> [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = sub <2 x i8> [[A]], [[O]] +; CHECK-NEXT: [[R:%.*]] = and <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