diff --git a/lib/Target/AArch64/AArch64ISelLowering.cpp b/lib/Target/AArch64/AArch64ISelLowering.cpp index 3376e3e11e1..b54f45675a6 100644 --- a/lib/Target/AArch64/AArch64ISelLowering.cpp +++ b/lib/Target/AArch64/AArch64ISelLowering.cpp @@ -2916,11 +2916,6 @@ SDValue AArch64TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const { isPowerOf2_64(LHS.getConstantOperandVal(1))) { SDValue Test = LHS.getOperand(0); uint64_t Mask = LHS.getConstantOperandVal(1); - - // TBZ only operates on i64's, but the ext should be free. - if (Test.getValueType() == MVT::i32) - Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64); - return DAG.getNode(AArch64ISD::TBZ, dl, MVT::Other, Chain, Test, DAG.getConstant(Log2_64(Mask), MVT::i64), Dest); } @@ -2936,18 +2931,29 @@ SDValue AArch64TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const { isPowerOf2_64(LHS.getConstantOperandVal(1))) { SDValue Test = LHS.getOperand(0); uint64_t Mask = LHS.getConstantOperandVal(1); - - // TBNZ only operates on i64's, but the ext should be free. - if (Test.getValueType() == MVT::i32) - Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64); - return DAG.getNode(AArch64ISD::TBNZ, dl, MVT::Other, Chain, Test, DAG.getConstant(Log2_64(Mask), MVT::i64), Dest); } return DAG.getNode(AArch64ISD::CBNZ, dl, MVT::Other, Chain, LHS, Dest); + } else if (CC == ISD::SETLT && LHS.getOpcode() != ISD::AND) { + // Don't combine AND since emitComparison converts the AND to an ANDS + // (a.k.a. TST) and the test in the test bit and branch instruction + // becomes redundant. This would also increase register pressure. + uint64_t Mask = LHS.getValueType().getSizeInBits() - 1; + return DAG.getNode(AArch64ISD::TBNZ, dl, MVT::Other, Chain, LHS, + DAG.getConstant(Mask, MVT::i64), Dest); } } + if (RHSC && RHSC->getSExtValue() == -1 && CC == ISD::SETGT && + LHS.getOpcode() != ISD::AND) { + // Don't combine AND since emitComparison converts the AND to an ANDS + // (a.k.a. TST) and the test in the test bit and branch instruction + // becomes redundant. This would also increase register pressure. + uint64_t Mask = LHS.getValueType().getSizeInBits() - 1; + return DAG.getNode(AArch64ISD::TBZ, dl, MVT::Other, Chain, LHS, + DAG.getConstant(Mask, MVT::i64), Dest); + } SDValue CCVal; SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl); diff --git a/test/CodeGen/AArch64/tbz-tbnz.ll b/test/CodeGen/AArch64/tbz-tbnz.ll new file mode 100644 index 00000000000..9969f28c327 --- /dev/null +++ b/test/CodeGen/AArch64/tbz-tbnz.ll @@ -0,0 +1,258 @@ +; RUN: llc -O1 -march=aarch64 < %s | FileCheck %s + +declare void @t() + +define void @test1(i32 %a) { +; CHECK-LABEL: @test1 +entry: + %sub = add nsw i32 %a, -12 + %cmp = icmp slt i32 %sub, 0 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:w[0-9]+]], w0, #12 +; CHECK: tbz [[CMP]], #31 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test2(i64 %a) { +; CHECK-LABEL: @test2 +entry: + %sub = add nsw i64 %a, -12 + %cmp = icmp slt i64 %sub, 0 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:x[0-9]+]], x0, #12 +; CHECK: tbz [[CMP]], #63 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test3(i32 %a) { +; CHECK-LABEL: @test3 +entry: + %sub = add nsw i32 %a, -12 + %cmp = icmp sgt i32 %sub, -1 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:w[0-9]+]], w0, #12 +; CHECK: tbnz [[CMP]], #31 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test4(i64 %a) { +; CHECK-LABEL: @test4 +entry: + %sub = add nsw i64 %a, -12 + %cmp = icmp sgt i64 %sub, -1 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:x[0-9]+]], x0, #12 +; CHECK: tbnz [[CMP]], #63 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test5(i32 %a) { +; CHECK-LABEL: @test5 +entry: + %sub = add nsw i32 %a, -12 + %cmp = icmp sge i32 %sub, 0 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:w[0-9]+]], w0, #12 +; CHECK: tbnz [[CMP]], #31 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test6(i64 %a) { +; CHECK-LABEL: @test6 +entry: + %sub = add nsw i64 %a, -12 + %cmp = icmp sge i64 %sub, 0 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:x[0-9]+]], x0, #12 +; CHECK: tbnz [[CMP]], #63 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test7(i32 %a) { +; CHECK-LABEL: @test7 +entry: + %sub = sub nsw i32 %a, 12 + %cmp = icmp slt i32 %sub, 0 + br i1 %cmp, label %if.then, label %if.end + +; CHECK: sub [[CMP:w[0-9]+]], w0, #12 +; CHECK: tbz [[CMP]], #31 + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test8(i64 %val1, i64 %val2, i64 %val3) { +; CHECK-LABEL: @test8 + %and1 = and i64 %val1, %val2 + %tst1 = icmp slt i64 %and1, 0 + br i1 %tst1, label %if.then1, label %if.end + +; CHECK: tst x0, x1 +; CHECK-NEXT: b.ge .L + +if.then1: + %and2 = and i64 %val2, %val3 + %tst2 = icmp sge i64 %and2, 0 + br i1 %tst2, label %if.then2, label %if.end + +; CHECK: and [[CMP:x[0-9]+]], x1, x2 +; CHECK-NOT: cmp +; CHECK: tbnz [[CMP]], #63, .LBB7_5 + +if.then2: + %shifted_op1 = shl i64 %val2, 63 + %shifted_and1 = and i64 %val1, %shifted_op1 + %tst3 = icmp slt i64 %shifted_and1, 0 + br i1 %tst3, label %if.then3, label %if.end + +; CHECK: tst x0, x1, lsl #63 +; CHECK: b.ge .L + +if.then3: + %shifted_op2 = shl i64 %val2, 62 + %shifted_and2 = and i64 %val1, %shifted_op2 + %tst4 = icmp sge i64 %shifted_and2, 0 + br i1 %tst4, label %if.then4, label %if.end + +; CHECK: tst x0, x1, lsl #62 +; CHECK: b.lt .L + +if.then4: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test9(i64 %val1) { +; CHECK-LABEL: @test9 + %tst = icmp slt i64 %val1, 0 + br i1 %tst, label %if.then, label %if.end + +; CHECK-NOT: cmp +; CHECK: tbz x0, #63, .L + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test10(i64 %val1) { +; CHECK-LABEL: @test10 + %tst = icmp slt i64 %val1, 0 + br i1 %tst, label %if.then, label %if.end + +; CHECK-NOT: cmp +; CHECK: tbz x0, #63, .L + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test11(i64 %val1, i64* %ptr) { +; CHECK-LABEL: @test11 + +; CHECK: ldr [[CMP:x[0-9]+]], [x1] +; CHECK-NOT: cmp +; CHECK: tbz [[CMP]], #63, .L + + %val = load i64* %ptr + %tst = icmp slt i64 %val, 0 + br i1 %tst, label %if.then, label %if.end + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test12(i64 %val1) { +; CHECK-LABEL: @test12 + %tst = icmp slt i64 %val1, 0 + br i1 %tst, label %if.then, label %if.end + +; CHECK-NOT: cmp +; CHECK: tbz x0, #63, .L + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +} + +define void @test13(i64 %val1, i64 %val2) { +; CHECK-LABEL: @test13 + %or = or i64 %val1, %val2 + %tst = icmp slt i64 %or, 0 + br i1 %tst, label %if.then, label %if.end + +; CHECK: orr [[CMP:x[0-9]+]], x0, x1 +; CHECK-NOT: cmp +; CHECK: tbz [[CMP]], #63, .L + +if.then: + call void @t() + br label %if.end + +if.end: + ret void +}