diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 473998bc260008..10a89b47e07537 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3530,6 +3530,52 @@ Instruction *InstCombinerImpl::foldICmpBinOpEqualityWithConstant( Value *And = Builder.CreateAnd(BOp0, NotBOC); return new ICmpInst(Pred, And, NotBOC); } + // (icmp eq (or (select cond, 0, NonZero), Other), 0) + // -> (and cond, (icmp eq Other, 0)) + // (icmp ne (or (select cond, NonZero, 0), Other), 0) + // -> (or cond, (icmp ne Other, 0)) + Value *Cond, *TV, *FV, *Other, *Sel; + if (C.isZero() && + match(BO, + m_OneUse(m_c_Or(m_CombineAnd(m_Value(Sel), + m_Select(m_Value(Cond), m_Value(TV), + m_Value(FV))), + m_Value(Other))))) { + const SimplifyQuery Q = SQ.getWithInstruction(&Cmp); + // Easy case is if eq/ne matches whether 0 is trueval/falseval. + if (Pred == ICmpInst::ICMP_EQ + ? (match(TV, m_Zero()) && isKnownNonZero(FV, Q)) + : (match(FV, m_Zero()) && isKnownNonZero(TV, Q))) { + Value *Cmp = Builder.CreateICmp( + Pred, Other, Constant::getNullValue(Other->getType())); + return BinaryOperator::Create( + Pred == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or, Cmp, + Cond); + } + // Harder case is if eq/ne matches whether 0 is falseval/trueval. In this + // case we need to invert the select condition so we need to be careful to + // avoid creating extra instructions. + // (icmp ne (or (select cond, 0, NonZero), Other), 0) + // -> (or (not cond), (icmp ne Other, 0)) + // (icmp eq (or (select cond, NonZero, 0), Other), 0) + // -> (and (not cond), (icmp eq Other, 0)) + // + // Only do this if the inner select has one use, in which case we are + // replacing `select` with `(not cond)`. Otherwise, we will create more + // uses. NB: Trying to freely invert cond doesn't make sense here, as if + // cond was freely invertable, the select arms would have been inverted. + if (Sel->hasOneUse() && + (Pred == ICmpInst::ICMP_EQ + ? (match(FV, m_Zero()) && isKnownNonZero(TV, Q)) + : (match(TV, m_Zero()) && isKnownNonZero(FV, Q)))) { + Value *NotCond = Builder.CreateNot(Cond); + Value *Cmp = Builder.CreateICmp( + Pred, Other, Constant::getNullValue(Other->getType())); + return BinaryOperator::Create( + Pred == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or, Cmp, + NotCond); + } + } break; } case Instruction::UDiv: diff --git a/llvm/test/Transforms/InstCombine/icmp-or-of-select-with-zero.ll b/llvm/test/Transforms/InstCombine/icmp-or-of-select-with-zero.ll index 22968bab481c15..90e0461f8b789e 100644 --- a/llvm/test/Transforms/InstCombine/icmp-or-of-select-with-zero.ll +++ b/llvm/test/Transforms/InstCombine/icmp-or-of-select-with-zero.ll @@ -5,10 +5,8 @@ declare void @use.i8(i8) declare void @use.i1(i1) define i1 @src_tv_eq(i1 %c0, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_tv_eq( -; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1 -; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C0:%.*]], i8 0, i8 [[Y]] -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = and i1 [[TMP1]], [[C0:%.*]] ; CHECK-NEXT: ret i1 [[R]] ; %y = add nuw i8 %yy, 1 @@ -52,10 +50,8 @@ define i1 @src_tv_eq_fail_tv_nonzero(i1 %c0, i8 %x, i8 %yy) { define i1 @src_fv_ne(i1 %c0, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_fv_ne( -; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1 -; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C0:%.*]], i8 [[Y]], i8 0 -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = or i1 [[TMP1]], [[C0:%.*]] ; CHECK-NEXT: ret i1 [[R]] ; %y = add nuw i8 %yy, 1 @@ -82,10 +78,9 @@ define i1 @src_fv_ne_fail_maybe_zero(i1 %c0, i8 %x, i8 %yy) { define i1 @src_tv_ne(i1 %c0, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_tv_ne( -; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1 -; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C0:%.*]], i8 0, i8 [[Y]] -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = xor i1 [[C0:%.*]], true +; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = or i1 [[TMP2]], [[TMP1]] ; CHECK-NEXT: ret i1 [[R]] ; %y = add nuw i8 %yy, 1 @@ -112,10 +107,9 @@ define i1 @src_tv_ne_fail_cmp_nonzero(i1 %c0, i8 %x, i8 %yy) { define i1 @src_fv_eq(i1 %c0, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_fv_eq( -; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1 -; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C0:%.*]], i8 [[Y]], i8 0 -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = xor i1 [[C0:%.*]], true +; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = and i1 [[TMP2]], [[TMP1]] ; CHECK-NEXT: ret i1 [[R]] ; %y = add nuw i8 %yy, 1 @@ -172,11 +166,11 @@ define i1 @src_fv_eq_invert2(i1 %c1, i8 %a, i8 %b, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_fv_eq_invert2( ; CHECK-NEXT: [[C0:%.*]] = icmp ugt i8 [[A:%.*]], [[B:%.*]] ; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1 -; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C0]], i8 [[Y]], i8 0 ; CHECK-NEXT: [[CC:%.*]] = or i1 [[C0]], [[C1:%.*]] ; CHECK-NEXT: [[SEL_OTHER:%.*]] = select i1 [[CC]], i8 [[Y]], i8 [[B]] -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = xor i1 [[C0]], true +; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = and i1 [[TMP2]], [[TMP1]] ; CHECK-NEXT: call void @use.i8(i8 [[SEL_OTHER]]) ; CHECK-NEXT: ret i1 [[R]] ; @@ -192,6 +186,9 @@ define i1 @src_fv_eq_invert2(i1 %c1, i8 %a, i8 %b, i8 %x, i8 %yy) { ret i1 %r } + + + define i1 @src_fv_eq_invert2_fail_wrong_binop(i1 %c1, i8 %a, i8 %b, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_fv_eq_invert2_fail_wrong_binop( ; CHECK-NEXT: [[C0:%.*]] = icmp ugt i8 [[A:%.*]], [[B:%.*]] @@ -266,6 +263,7 @@ define i1 @src_fv_eq_invert3(i8 %a, i8 %b, i8 %x, i8 %yy) { ret i1 %r } + define i1 @src_tv_ne_invert(i1 %c1, i8 %a, i8 %b, i8 %x, i8 %yy) { ; CHECK-LABEL: @src_tv_ne_invert( ; CHECK-NEXT: [[NOT_C0:%.*]] = icmp ugt i8 [[A:%.*]], [[B:%.*]] @@ -275,8 +273,8 @@ define i1 @src_tv_ne_invert(i1 %c1, i8 %a, i8 %b, i8 %x, i8 %yy) { ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[NOT_C0]], i8 [[Y]], i8 0 ; CHECK-NEXT: [[CC:%.*]] = or i1 [[C0]], [[C1:%.*]] ; CHECK-NEXT: [[SEL_OTHER:%.*]] = select i1 [[CC]], i8 [[Y]], i8 [[B]] -; CHECK-NEXT: [[SELX:%.*]] = or i8 [[SEL]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[SELX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i8 [[X:%.*]], 0 +; CHECK-NEXT: [[R:%.*]] = or i1 [[TMP1]], [[NOT_C0]] ; CHECK-NEXT: call void @use.i8(i8 [[SEL]]) ; CHECK-NEXT: call void @use.i8(i8 [[SEL_OTHER]]) ; CHECK-NEXT: ret i1 [[R]]