Revert r372333: [DAG][X86] Convert isNegatibleForFree/GetNegatedExpression to a target hook (PR42863)

Reason: this caused severe compile time regressions in JAX.
See email thread  of original revision on llvm-commits for details:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190923/697042.html

llvm-svn: 372756

1 files changed, 0 insertions, 240 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 0ab2f5a292a..2d09b2cc9df 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -5333,246 +5333,6 @@ verifyReturnAddressArgumentIsConstant(SDValue Op, SelectionDAG &DAG) const {
   return false;
 }
 
-char TargetLowering::isNegatibleForFree(SDValue Op, SelectionDAG &DAG,
-                                        bool LegalOperations, bool ForCodeSize,
-                                        unsigned Depth) const {
-  // fneg is removable even if it has multiple uses.
-  if (Op.getOpcode() == ISD::FNEG)
-    return 2;
-
-  // Don't allow anything with multiple uses unless we know it is free.
-  EVT VT = Op.getValueType();
-  const SDNodeFlags Flags = Op->getFlags();
-  const TargetOptions &Options = DAG.getTarget().Options;
-  if (!Op.hasOneUse() && !(Op.getOpcode() == ISD::FP_EXTEND &&
-                           isFPExtFree(VT, Op.getOperand(0).getValueType())))
-    return 0;
-
-  // Don't recurse exponentially.
-  if (Depth > SelectionDAG::MaxRecursionDepth)
-    return 0;
-
-  switch (Op.getOpcode()) {
-  case ISD::ConstantFP: {
-    if (!LegalOperations)
-      return 1;
-
-    // Don't invert constant FP values after legalization unless the target says
-    // the negated constant is legal.
-    return isOperationLegal(ISD::ConstantFP, VT) ||
-           isFPImmLegal(neg(cast<ConstantFPSDNode>(Op)->getValueAPF()), VT,
-                        ForCodeSize);
-  }
-  case ISD::BUILD_VECTOR: {
-    // Only permit BUILD_VECTOR of constants.
-    if (llvm::any_of(Op->op_values(), [&](SDValue N) {
-          return !N.isUndef() && !isa<ConstantFPSDNode>(N);
-        }))
-      return 0;
-    if (!LegalOperations)
-      return 1;
-    if (isOperationLegal(ISD::ConstantFP, VT) &&
-        isOperationLegal(ISD::BUILD_VECTOR, VT))
-      return 1;
-    return llvm::all_of(Op->op_values(), [&](SDValue N) {
-      return N.isUndef() ||
-             isFPImmLegal(neg(cast<ConstantFPSDNode>(N)->getValueAPF()), VT,
-                          ForCodeSize);
-    });
-  }
-  case ISD::FADD:
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
-      return 0;
-
-    // After operation legalization, it might not be legal to create new FSUBs.
-    if (LegalOperations && !isOperationLegalOrCustom(ISD::FSUB, VT))
-      return 0;
-
-    // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
-    if (char V = isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations,
-                                    ForCodeSize, Depth + 1))
-      return V;
-    // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
-    return isNegatibleForFree(Op.getOperand(1), DAG, LegalOperations,
-                              ForCodeSize, Depth + 1);
-  case ISD::FSUB:
-    // We can't turn -(A-B) into B-A when we honor signed zeros.
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
-      return 0;
-
-    // fold (fneg (fsub A, B)) -> (fsub B, A)
-    return 1;
-
-  case ISD::FMUL:
-  case ISD::FDIV:
-    // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
-    if (char V = isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations,
-                                    ForCodeSize, Depth + 1))
-      return V;
-
-    // Ignore X * 2.0 because that is expected to be canonicalized to X + X.
-    if (auto *C = isConstOrConstSplatFP(Op.getOperand(1)))
-      if (C->isExactlyValue(2.0) && Op.getOpcode() == ISD::FMUL)
-        return 0;
-
-    return isNegatibleForFree(Op.getOperand(1), DAG, LegalOperations,
-                              ForCodeSize, Depth + 1);
-
-  case ISD::FMA:
-  case ISD::FMAD: {
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
-      return 0;
-
-    // fold (fneg (fma X, Y, Z)) -> (fma (fneg X), Y, (fneg Z))
-    // fold (fneg (fma X, Y, Z)) -> (fma X, (fneg Y), (fneg Z))
-    char V2 = isNegatibleForFree(Op.getOperand(2), DAG, LegalOperations,
-                                 ForCodeSize, Depth + 1);
-    if (!V2)
-      return 0;
-
-    // One of Op0/Op1 must be cheaply negatible, then select the cheapest.
-    char V0 = isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations,
-                                 ForCodeSize, Depth + 1);
-    char V1 = isNegatibleForFree(Op.getOperand(1), DAG, LegalOperations,
-                                 ForCodeSize, Depth + 1);
-    char V01 = std::max(V0, V1);
-    return V01 ? std::max(V01, V2) : 0;
-  }
-
-  case ISD::FP_EXTEND:
-  case ISD::FP_ROUND:
-  case ISD::FSIN:
-    return isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations,
-                              ForCodeSize, Depth + 1);
-  }
-
-  return 0;
-}
-
-SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
-                                             bool LegalOperations,
-                                             bool ForCodeSize,
-                                             unsigned Depth) const {
-  // fneg is removable even if it has multiple uses.
-  if (Op.getOpcode() == ISD::FNEG)
-    return Op.getOperand(0);
-
-  assert(Depth <= SelectionDAG::MaxRecursionDepth &&
-         "getNegatedExpression doesn't match isNegatibleForFree");
-  const SDNodeFlags Flags = Op->getFlags();
-
-  switch (Op.getOpcode()) {
-  case ISD::ConstantFP: {
-    APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
-    V.changeSign();
-    return DAG.getConstantFP(V, SDLoc(Op), Op.getValueType());
-  }
-  case ISD::BUILD_VECTOR: {
-    SmallVector<SDValue, 4> Ops;
-    for (SDValue C : Op->op_values()) {
-      if (C.isUndef()) {
-        Ops.push_back(C);
-        continue;
-      }
-      APFloat V = cast<ConstantFPSDNode>(C)->getValueAPF();
-      V.changeSign();
-      Ops.push_back(DAG.getConstantFP(V, SDLoc(Op), C.getValueType()));
-    }
-    return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Ops);
-  }
-  case ISD::FADD:
-    assert((DAG.getTarget().Options.NoSignedZerosFPMath ||
-            Flags.hasNoSignedZeros()) &&
-           "Expected NSZ fp-flag");
-
-    // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
-    if (isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations, ForCodeSize,
-                           Depth + 1))
-      return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
-                         getNegatedExpression(Op.getOperand(0), DAG,
-                                              LegalOperations, ForCodeSize,
-                                              Depth + 1),
-                         Op.getOperand(1), Flags);
-    // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
-    return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
-                       getNegatedExpression(Op.getOperand(1), DAG,
-                                            LegalOperations, ForCodeSize,
-                                            Depth + 1),
-                       Op.getOperand(0), Flags);
-  case ISD::FSUB:
-    // fold (fneg (fsub 0, B)) -> B
-    if (ConstantFPSDNode *N0CFP =
-            isConstOrConstSplatFP(Op.getOperand(0), /*AllowUndefs*/ true))
-      if (N0CFP->isZero())
-        return Op.getOperand(1);
-
-    // fold (fneg (fsub A, B)) -> (fsub B, A)
-    return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
-                       Op.getOperand(1), Op.getOperand(0), Flags);
-
-  case ISD::FMUL:
-  case ISD::FDIV:
-    // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
-    if (isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations, ForCodeSize,
-                           Depth + 1))
-      return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
-                         getNegatedExpression(Op.getOperand(0), DAG,
-                                              LegalOperations, ForCodeSize,
-                                              Depth + 1),
-                         Op.getOperand(1), Flags);
-
-    // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
-    return DAG.getNode(
-        Op.getOpcode(), SDLoc(Op), Op.getValueType(), Op.getOperand(0),
-        getNegatedExpression(Op.getOperand(1), DAG, LegalOperations,
-                             ForCodeSize, Depth + 1),
-        Flags);
-
-  case ISD::FMA:
-  case ISD::FMAD: {
-    assert((DAG.getTarget().Options.NoSignedZerosFPMath ||
-            Flags.hasNoSignedZeros()) &&
-           "Expected NSZ fp-flag");
-
-    SDValue Neg2 = getNegatedExpression(Op.getOperand(2), DAG, LegalOperations,
-                                        ForCodeSize, Depth + 1);
-
-    char V0 = isNegatibleForFree(Op.getOperand(0), DAG, LegalOperations,
-                                 ForCodeSize, Depth + 1);
-    char V1 = isNegatibleForFree(Op.getOperand(1), DAG, LegalOperations,
-                                 ForCodeSize, Depth + 1);
-    if (V0 >= V1) {
-      // fold (fneg (fma X, Y, Z)) -> (fma (fneg X), Y, (fneg Z))
-      SDValue Neg0 = getNegatedExpression(
-          Op.getOperand(0), DAG, LegalOperations, ForCodeSize, Depth + 1);
-      return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(), Neg0,
-                         Op.getOperand(1), Neg2, Flags);
-    }
-
-    // fold (fneg (fma X, Y, Z)) -> (fma X, (fneg Y), (fneg Z))
-    SDValue Neg1 = getNegatedExpression(Op.getOperand(1), DAG, LegalOperations,
-                                        ForCodeSize, Depth + 1);
-    return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
-                       Op.getOperand(0), Neg1, Neg2, Flags);
-  }
-
-  case ISD::FP_EXTEND:
-  case ISD::FSIN:
-    return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
-                       getNegatedExpression(Op.getOperand(0), DAG,
-                                            LegalOperations, ForCodeSize,
-                                            Depth + 1));
-  case ISD::FP_ROUND:
-    return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
-                       getNegatedExpression(Op.getOperand(0), DAG,
-                                            LegalOperations, ForCodeSize,
-                                            Depth + 1),
-                       Op.getOperand(1));
-  }
-
-  llvm_unreachable("Unknown code");
-}
-
 //===----------------------------------------------------------------------===//
 // Legalization Utilities
 //===----------------------------------------------------------------------===//