diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1448,6 +1448,13 @@ Builder.CreateIntrinsic(Intrinsic::umax, {I.getType()}, {A, B})); } + // ctpop(A) + ctpop(B) => ctpop(A | B) if A and B have no bits set in common. + if (match(&I, + m_c_BinOp(m_OneUse(m_Intrinsic(m_Value(A))), + m_OneUse(m_Intrinsic(m_Value(B))))) && + haveNoCommonBitsSet(A, B, DL, &AC, &I, &DT)) + return BinaryOperator::CreateOr(A, B); + return Changed ? &I : nullptr; } diff --git a/llvm/test/Transforms/InstCombine/ctpop.ll b/llvm/test/Transforms/InstCombine/ctpop.ll --- a/llvm/test/Transforms/InstCombine/ctpop.ll +++ b/llvm/test/Transforms/InstCombine/ctpop.ll @@ -203,11 +203,7 @@ define i32 @ctpop_add_no_common_bits(i32 %a, i32 %b) { ; CHECK-LABEL: @ctpop_add_no_common_bits( -; CHECK-NEXT: [[SHL16:%.*]] = shl i32 [[B:%.*]], 16 -; CHECK-NEXT: [[CTPOP1:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[SHL16]]), !range [[RNG3:![0-9]+]] -; CHECK-NEXT: [[LSHL16:%.*]] = lshr i32 [[B]], 16 -; CHECK-NEXT: [[CTPOP2:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[LSHL16]]), !range [[RNG3]] -; CHECK-NEXT: [[RES:%.*]] = add nuw nsw i32 [[CTPOP1]], [[CTPOP2]] +; CHECK-NEXT: [[RES:%.*]] = call i32 @llvm.fshl.i32(i32 [[B:%.*]], i32 [[B]], i32 16) ; CHECK-NEXT: ret i32 [[RES]] ; %shl16 = shl i32 %b, 16 @@ -220,11 +216,7 @@ define <2 x i32> @ctpop_add_no_common_bits_vec(<2 x i32> %a, <2 x i32> %b) { ; CHECK-LABEL: @ctpop_add_no_common_bits_vec( -; CHECK-NEXT: [[SHL16:%.*]] = shl <2 x i32> [[A:%.*]], -; CHECK-NEXT: [[CTPOP1:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[SHL16]]) -; CHECK-NEXT: [[LSHL16:%.*]] = lshr <2 x i32> [[B:%.*]], -; CHECK-NEXT: [[CTPOP2:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[LSHL16]]) -; CHECK-NEXT: [[RES:%.*]] = add nuw nsw <2 x i32> [[CTPOP1]], [[CTPOP2]] +; CHECK-NEXT: [[RES:%.*]] = call <2 x i32> @llvm.fshl.v2i32(<2 x i32> [[A:%.*]], <2 x i32> [[B:%.*]], <2 x i32> ) ; CHECK-NEXT: ret <2 x i32> [[RES]] ; %shl16 = shl <2 x i32> %a,