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-rw-r--r--lib/Target/X86/X86ISelLowering.cpp122
1 files changed, 112 insertions, 10 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index d735e63..9e1da14 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -14036,7 +14036,7 @@ static SDValue PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
//
// where Op could be BRCOND or CMOV.
//
-static SDValue BoolTestSetCCCombine(SDValue Cmp, X86::CondCode &CC) {
+static SDValue checkBoolTestSetCCCombine(SDValue Cmp, X86::CondCode &CC) {
// Quit if not CMP and SUB with its value result used.
if (Cmp.getOpcode() != X86ISD::CMP &&
(Cmp.getOpcode() != X86ISD::SUB || Cmp.getNode()->hasAnyUseOfValue(0)))
@@ -14087,7 +14087,85 @@ static SDValue BoolTestSetCCCombine(SDValue Cmp, X86::CondCode &CC) {
return SetCC.getOperand(1);
}
-static bool IsValidFCMOVCondition(X86::CondCode CC) {
+/// checkFlaggedOrCombine - DAG combination on X86ISD::OR, i.e. with EFLAGS
+/// updated. If only flag result is used and the result is evaluated from a
+/// series of element extraction, try to combine it into a PTEST.
+static SDValue checkFlaggedOrCombine(SDValue Or, X86::CondCode &CC,
+ SelectionDAG &DAG,
+ const X86Subtarget *Subtarget) {
+ SDNode *N = Or.getNode();
+ DebugLoc DL = N->getDebugLoc();
+
+ // Only SSE4.1 and beyond supports PTEST or like.
+ if (!Subtarget->hasSSE41())
+ return SDValue();
+
+ if (N->getOpcode() != X86ISD::OR)
+ return SDValue();
+
+ // Quit if the value result of OR is used.
+ if (N->hasAnyUseOfValue(0))
+ return SDValue();
+
+ // Quit if not used as a boolean value.
+ if (CC != X86::COND_E && CC != X86::COND_NE)
+ return SDValue();
+
+ SmallVector<SDValue, 8> Opnds;
+ SDValue VecIn;
+ EVT VT = MVT::Other;
+ unsigned Mask = 0;
+
+ // Recognize a special case where a vector is casted into wide integer to
+ // test all 0s.
+ Opnds.push_back(N->getOperand(0));
+ Opnds.push_back(N->getOperand(1));
+
+ for (unsigned Slot = 0, e = Opnds.size(); Slot < e; ++Slot) {
+ SmallVector<SDValue, 8>::const_iterator I = Opnds.begin() + Slot;
+ // BFS traverse all OR'd operands.
+ if (I->getOpcode() == ISD::OR) {
+ Opnds.push_back(I->getOperand(0));
+ Opnds.push_back(I->getOperand(1));
+ // Re-evaluate the number of nodes to be traversed.
+ e = Opnds.size();
+ continue;
+ }
+
+ // Quit if a non-EXTRACT_VECTOR_ELT
+ if (I->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
+ return SDValue();
+
+ // Quit if without a constant index.
+ SDValue Idx = I->getOperand(1);
+ if (!isa<ConstantSDNode>(Idx))
+ return SDValue();
+
+ // Check if all elements are extracted from the same vector.
+ SDValue ExtractedFromVec = I->getOperand(0);
+ if (VecIn.getNode() == 0) {
+ VT = ExtractedFromVec.getValueType();
+ // FIXME: only 128-bit vector is supported so far.
+ if (!VT.is128BitVector())
+ return SDValue();
+ VecIn = ExtractedFromVec;
+ } else if (VecIn != ExtractedFromVec)
+ return SDValue();
+
+ // Record the constant index.
+ Mask |= 1U << cast<ConstantSDNode>(Idx)->getZExtValue();
+ }
+
+ assert(VT.is128BitVector() && "Only 128-bit vector PTEST is supported so far.");
+
+ // Quit if not all elements are used.
+ if (Mask != (1U << VT.getVectorNumElements()) - 1U)
+ return SDValue();
+
+ return DAG.getNode(X86ISD::PTEST, DL, MVT::i32, VecIn, VecIn);
+}
+
+static bool isValidFCMOVCondition(X86::CondCode CC) {
switch (CC) {
default:
return false;
@@ -14105,7 +14183,8 @@ static bool IsValidFCMOVCondition(X86::CondCode CC) {
/// Optimize X86ISD::CMOV [LHS, RHS, CONDCODE (e.g. X86::COND_NE), CONDVAL]
static SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG,
- TargetLowering::DAGCombinerInfo &DCI) {
+ TargetLowering::DAGCombinerInfo &DCI,
+ const X86Subtarget *Subtarget) {
DebugLoc DL = N->getDebugLoc();
// If the flag operand isn't dead, don't touch this CMOV.
@@ -14130,10 +14209,18 @@ static SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG,
SDValue Flags;
- Flags = BoolTestSetCCCombine(Cond, CC);
+ Flags = checkBoolTestSetCCCombine(Cond, CC);
if (Flags.getNode() &&
// Extra check as FCMOV only supports a subset of X86 cond.
- (FalseOp.getValueType() != MVT::f80 || IsValidFCMOVCondition(CC))) {
+ (FalseOp.getValueType() != MVT::f80 || isValidFCMOVCondition(CC))) {
+ SDValue Ops[] = { FalseOp, TrueOp,
+ DAG.getConstant(CC, MVT::i8), Flags };
+ return DAG.getNode(X86ISD::CMOV, DL, N->getVTList(),
+ Ops, array_lengthof(Ops));
+ }
+
+ Flags = checkFlaggedOrCombine(Cond, CC, DAG, Subtarget);
+ if (Flags.getNode()) {
SDValue Ops[] = { FalseOp, TrueOp,
DAG.getConstant(CC, MVT::i8), Flags };
return DAG.getNode(X86ISD::CMOV, DL, N->getVTList(),
@@ -15641,7 +15728,9 @@ static SDValue PerformISDSETCCCombine(SDNode *N, SelectionDAG &DAG) {
}
// Optimize RES = X86ISD::SETCC CONDCODE, EFLAG_INPUT
-static SDValue PerformSETCCCombine(SDNode *N, SelectionDAG &DAG) {
+static SDValue PerformSETCCCombine(SDNode *N, SelectionDAG &DAG,
+ TargetLowering::DAGCombinerInfo &DCI,
+ const X86Subtarget *Subtarget) {
DebugLoc DL = N->getDebugLoc();
X86::CondCode CC = X86::CondCode(N->getConstantOperandVal(0));
SDValue EFLAGS = N->getOperand(1);
@@ -15657,7 +15746,13 @@ static SDValue PerformSETCCCombine(SDNode *N, SelectionDAG &DAG) {
SDValue Flags;
- Flags = BoolTestSetCCCombine(EFLAGS, CC);
+ Flags = checkBoolTestSetCCCombine(EFLAGS, CC);
+ if (Flags.getNode()) {
+ SDValue Cond = DAG.getConstant(CC, MVT::i8);
+ return DAG.getNode(X86ISD::SETCC, DL, N->getVTList(), Cond, Flags);
+ }
+
+ Flags = checkFlaggedOrCombine(EFLAGS, CC, DAG, Subtarget);
if (Flags.getNode()) {
SDValue Cond = DAG.getConstant(CC, MVT::i8);
return DAG.getNode(X86ISD::SETCC, DL, N->getVTList(), Cond, Flags);
@@ -15679,7 +15774,14 @@ static SDValue PerformBrCondCombine(SDNode *N, SelectionDAG &DAG,
SDValue Flags;
- Flags = BoolTestSetCCCombine(EFLAGS, CC);
+ Flags = checkBoolTestSetCCCombine(EFLAGS, CC);
+ if (Flags.getNode()) {
+ SDValue Cond = DAG.getConstant(CC, MVT::i8);
+ return DAG.getNode(X86ISD::BRCOND, DL, N->getVTList(), Chain, Dest, Cond,
+ Flags);
+ }
+
+ Flags = checkFlaggedOrCombine(EFLAGS, CC, DAG, Subtarget);
if (Flags.getNode()) {
SDValue Cond = DAG.getConstant(CC, MVT::i8);
return DAG.getNode(X86ISD::BRCOND, DL, N->getVTList(), Chain, Dest, Cond,
@@ -15874,7 +15976,7 @@ SDValue X86TargetLowering::PerformDAGCombine(SDNode *N,
return PerformEXTRACT_VECTOR_ELTCombine(N, DAG, DCI);
case ISD::VSELECT:
case ISD::SELECT: return PerformSELECTCombine(N, DAG, DCI, Subtarget);
- case X86ISD::CMOV: return PerformCMOVCombine(N, DAG, DCI);
+ case X86ISD::CMOV: return PerformCMOVCombine(N, DAG, DCI, Subtarget);
case ISD::ADD: return PerformAddCombine(N, DAG, Subtarget);
case ISD::SUB: return PerformSubCombine(N, DAG, Subtarget);
case X86ISD::ADC: return PerformADCCombine(N, DAG, DCI);
@@ -15904,7 +16006,7 @@ SDValue X86TargetLowering::PerformDAGCombine(SDNode *N,
case ISD::SIGN_EXTEND: return PerformSExtCombine(N, DAG, DCI, Subtarget);
case ISD::TRUNCATE: return PerformTruncateCombine(N, DAG, DCI);
case ISD::SETCC: return PerformISDSETCCCombine(N, DAG);
- case X86ISD::SETCC: return PerformSETCCCombine(N, DAG);
+ case X86ISD::SETCC: return PerformSETCCCombine(N, DAG, DCI, Subtarget);
case X86ISD::BRCOND: return PerformBrCondCombine(N, DAG, DCI, Subtarget);
case X86ISD::SHUFP: // Handle all target specific shuffles
case X86ISD::PALIGN:
generated by cgit v1.1 at 2025-02-08 14:09:39 +0000