-// CMPEQCombine - Recognize the distinctive (AND (setcc ...) (setcc ..))
-// where both setccs reference the same FP CMP, and rewrite for CMPEQSS
-// and friends. Likewise for OR -> CMPNEQSS.
-static SDValue CMPEQCombine(SDNode *N, SelectionDAG &DAG,
- TargetLowering::DAGCombinerInfo &DCI,
- const X86Subtarget *Subtarget) {
- unsigned opcode;
-
- // SSE1 supports CMP{eq|ne}SS, and SSE2 added CMP{eq|ne}SD, but
- // we're requiring SSE2 for both.
- if (Subtarget->hasSSE2() && isAndOrOfSetCCs(SDValue(N, 0U), opcode)) {
- SDValue N0 = N->getOperand(0);
- SDValue N1 = N->getOperand(1);
- SDValue CMP = N0->getOperand(1);
- SDValue CMP0 = CMP->getOperand(0);
- SDValue CMP1 = CMP->getOperand(1);
- EVT VT = CMP0.getValueType();
- DebugLoc DL = N->getDebugLoc();
-
- if (VT == MVT::f32 || VT == MVT::f64) {
- bool ExpectingFlags = false;
- // Check for any users that want flags:
- for (SDNode::use_iterator UI = N->use_begin(),
- UE = N->use_end();
- !ExpectingFlags && UI != UE; ++UI)
- switch (UI->getOpcode()) {
- default:
- case ISD::BR_CC:
- case ISD::BRCOND:
- case ISD::SELECT:
- ExpectingFlags = true;
- break;
- case ISD::CopyToReg:
- case ISD::SIGN_EXTEND:
- case ISD::ZERO_EXTEND:
- case ISD::ANY_EXTEND:
- break;
- }
-
- if (!ExpectingFlags) {
- enum X86::CondCode cc0 = (enum X86::CondCode)N0.getConstantOperandVal(0);
- enum X86::CondCode cc1 = (enum X86::CondCode)N1.getConstantOperandVal(0);
-
- if (cc1 == X86::COND_E || cc1 == X86::COND_NE) {
- X86::CondCode tmp = cc0;
- cc0 = cc1;
- cc1 = tmp;
- }
-
- if ((cc0 == X86::COND_E && cc1 == X86::COND_NP) ||
- (cc0 == X86::COND_NE && cc1 == X86::COND_P)) {
- bool is64BitFP = (CMP0.getValueType() == MVT::f64);
- X86ISD::NodeType NTOperator = is64BitFP ?
- X86ISD::FSETCCsd : X86ISD::FSETCCss;
- // FIXME: need symbolic constants for these magic numbers.
- // See X86ATTInstPrinter.cpp:printSSECC().
- unsigned x86cc = (cc0 == X86::COND_E) ? 0 : 4;
- SDValue OnesOrZeroesF = DAG.getNode(NTOperator, DL, MVT::f32, CMP0, CMP1,
- DAG.getConstant(x86cc, MVT::i8));
- SDValue OnesOrZeroesI = DAG.getNode(ISD::BITCAST, DL, MVT::i32,
- OnesOrZeroesF);
- SDValue ANDed = DAG.getNode(ISD::AND, DL, MVT::i32, OnesOrZeroesI,
- DAG.getConstant(1, MVT::i32));
- SDValue OneBitOfTruth = DAG.getNode(ISD::TRUNCATE, DL, MVT::i8, ANDed);
- return OneBitOfTruth;
- }
- }
- }
- }
- return SDValue();
-}
-