Split type expansion into ExpandInteger and ExpandFloat

rather than bundling them together.  Rename FloatToInt
to PromoteFloat (better, if not perfect).  Reorganize
files by types rather than by operations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52408 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 452 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
new file mode 100644
index 0000000000..d4e5a45876
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
@@ -0,0 +1,452 @@
+//===-------- LegalizeFloatTypes.cpp - Legalization of float types --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements float type expansion and conversion of float types to
+// integer types on behalf of LegalizeTypes.
+// Converting to integer is the act of turning a computation in an illegal
+// floating point type into a computation in an integer type of the same size.
+// For example, turning f32 arithmetic into operations using i32.  Also known as
+// "soft float".  The result is equivalent to bitcasting the float value to the
+// integer type.
+// Expansion is the act of changing a computation in an illegal type to be a
+// computation in multiple registers of a smaller type.  For example,
+// implementing ppcf128 arithmetic in two f64 registers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LegalizeTypes.h"
+#include "llvm/CodeGen/PseudoSourceValue.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+using namespace llvm;
+
+/// GetFPLibCall - Return the right libcall for the given floating point type.
+static RTLIB::Libcall GetFPLibCall(MVT VT,
+                                   RTLIB::Libcall Call_F32,
+                                   RTLIB::Libcall Call_F64,
+                                   RTLIB::Libcall Call_F80,
+                                   RTLIB::Libcall Call_PPCF128) {
+  return
+    VT == MVT::f32 ? Call_F32 :
+    VT == MVT::f64 ? Call_F64 :
+    VT == MVT::f80 ? Call_F80 :
+    VT == MVT::ppcf128 ? Call_PPCF128 :
+    RTLIB::UNKNOWN_LIBCALL;
+}
+
+//===----------------------------------------------------------------------===//
+//  Result Float to Integer Conversion.
+//===----------------------------------------------------------------------===//
+
+void DAGTypeLegalizer::PromoteFloatResult(SDNode *N, unsigned ResNo) {
+  DEBUG(cerr << "Promote float result " << ResNo << ": "; N->dump(&DAG);
+        cerr << "\n");
+  SDOperand R = SDOperand();
+
+  // FIXME: Custom lowering for float-to-int?
+#if 0
+  // See if the target wants to custom convert this node to an integer.
+  if (TLI.getOperationAction(N->getOpcode(), N->getValueType(0)) ==
+      TargetLowering::Custom) {
+    // If the target wants to, allow it to lower this itself.
+    if (SDNode *P = TLI.FloatToIntOperationResult(N, DAG)) {
+      // Everything that once used N now uses P.  We are guaranteed that the
+      // result value types of N and the result value types of P match.
+      ReplaceNodeWith(N, P);
+      return;
+    }
+  }
+#endif
+
+  switch (N->getOpcode()) {
+  default:
+#ifndef NDEBUG
+    cerr << "PromoteFloatResult #" << ResNo << ": ";
+    N->dump(&DAG); cerr << "\n";
+#endif
+    assert(0 && "Do not know how to convert the result of this operator!");
+    abort();
+
+    case ISD::BIT_CONVERT: R = PromoteFloatRes_BIT_CONVERT(N); break;
+    case ISD::BUILD_PAIR:  R = PromoteFloatRes_BUILD_PAIR(N); break;
+    case ISD::ConstantFP:
+      R = PromoteFloatRes_ConstantFP(cast<ConstantFPSDNode>(N));
+      break;
+    case ISD::FCOPYSIGN:   R = PromoteFloatRes_FCOPYSIGN(N); break;
+    case ISD::LOAD:        R = PromoteFloatRes_LOAD(N); break;
+    case ISD::SINT_TO_FP:
+    case ISD::UINT_TO_FP:  R = PromoteFloatRes_XINT_TO_FP(N); break;
+
+    case ISD::FADD: R = PromoteFloatRes_FADD(N); break;
+    case ISD::FMUL: R = PromoteFloatRes_FMUL(N); break;
+    case ISD::FSUB: R = PromoteFloatRes_FSUB(N); break;
+  }
+
+  // If R is null, the sub-method took care of registering the result.
+  if (R.Val)
+    SetPromotedFloat(SDOperand(N, ResNo), R);
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_BIT_CONVERT(SDNode *N) {
+  return BitConvertToInteger(N->getOperand(0));
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_BUILD_PAIR(SDNode *N) {
+  // Convert the inputs to integers, and build a new pair out of them.
+  return DAG.getNode(ISD::BUILD_PAIR,
+                     TLI.getTypeToTransformTo(N->getValueType(0)),
+                     BitConvertToInteger(N->getOperand(0)),
+                     BitConvertToInteger(N->getOperand(1)));
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_ConstantFP(ConstantFPSDNode *N) {
+  return DAG.getConstant(N->getValueAPF().convertToAPInt(),
+                         TLI.getTypeToTransformTo(N->getValueType(0)));
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_FADD(SDNode *N) {
+  MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
+  SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)),
+                       GetPromotedFloat(N->getOperand(1)) };
+  return MakeLibCall(GetFPLibCall(N->getValueType(0),
+                                  RTLIB::ADD_F32,
+                                  RTLIB::ADD_F64,
+                                  RTLIB::ADD_F80,
+                                  RTLIB::ADD_PPCF128),
+                     NVT, Ops, 2, false/*sign irrelevant*/);
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_FCOPYSIGN(SDNode *N) {
+  SDOperand LHS = GetPromotedFloat(N->getOperand(0));
+  SDOperand RHS = BitConvertToInteger(N->getOperand(1));
+
+  MVT LVT = LHS.getValueType();
+  MVT RVT = RHS.getValueType();
+
+  unsigned LSize = LVT.getSizeInBits();
+  unsigned RSize = RVT.getSizeInBits();
+
+  // First get the sign bit of second operand.
+  SDOperand SignBit = DAG.getNode(ISD::SHL, RVT, DAG.getConstant(1, RVT),
+                                  DAG.getConstant(RSize - 1,
+                                                  TLI.getShiftAmountTy()));
+  SignBit = DAG.getNode(ISD::AND, RVT, RHS, SignBit);
+
+  // Shift right or sign-extend it if the two operands have different types.
+  int SizeDiff = RVT.getSizeInBits() - LVT.getSizeInBits();
+  if (SizeDiff > 0) {
+    SignBit = DAG.getNode(ISD::SRL, RVT, SignBit,
+                          DAG.getConstant(SizeDiff, TLI.getShiftAmountTy()));
+    SignBit = DAG.getNode(ISD::TRUNCATE, LVT, SignBit);
+  } else if (SizeDiff < 0) {
+    SignBit = DAG.getNode(ISD::ANY_EXTEND, LVT, SignBit);
+    SignBit = DAG.getNode(ISD::SHL, LVT, SignBit,
+                          DAG.getConstant(-SizeDiff, TLI.getShiftAmountTy()));
+  }
+
+  // Clear the sign bit of the first operand.
+  SDOperand Mask = DAG.getNode(ISD::SHL, LVT, DAG.getConstant(1, LVT),
+                               DAG.getConstant(LSize - 1,
+                                               TLI.getShiftAmountTy()));
+  Mask = DAG.getNode(ISD::SUB, LVT, Mask, DAG.getConstant(1, LVT));
+  LHS = DAG.getNode(ISD::AND, LVT, LHS, Mask);
+
+  // Or the value with the sign bit.
+  return DAG.getNode(ISD::OR, LVT, LHS, SignBit);
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_FMUL(SDNode *N) {
+  MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
+  SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)),
+                       GetPromotedFloat(N->getOperand(1)) };
+  return MakeLibCall(GetFPLibCall(N->getValueType(0),
+                                  RTLIB::MUL_F32,
+                                  RTLIB::MUL_F64,
+                                  RTLIB::MUL_F80,
+                                  RTLIB::MUL_PPCF128),
+                     NVT, Ops, 2, false/*sign irrelevant*/);
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_FSUB(SDNode *N) {
+  MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
+  SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)),
+                       GetPromotedFloat(N->getOperand(1)) };
+  return MakeLibCall(GetFPLibCall(N->getValueType(0),
+                                  RTLIB::SUB_F32,
+                                  RTLIB::SUB_F64,
+                                  RTLIB::SUB_F80,
+                                  RTLIB::SUB_PPCF128),
+                     NVT, Ops, 2, false/*sign irrelevant*/);
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_LOAD(SDNode *N) {
+  LoadSDNode *L = cast<LoadSDNode>(N);
+  MVT VT = N->getValueType(0);
+  MVT NVT = TLI.getTypeToTransformTo(VT);
+
+  if (L->getExtensionType() == ISD::NON_EXTLOAD)
+     return DAG.getLoad(L->getAddressingMode(), L->getExtensionType(),
+                        NVT, L->getChain(), L->getBasePtr(), L->getOffset(),
+                        L->getSrcValue(), L->getSrcValueOffset(), NVT,
+                        L->isVolatile(), L->getAlignment());
+
+  // Do a non-extending load followed by FP_EXTEND.
+  SDOperand NL = DAG.getLoad(L->getAddressingMode(), ISD::NON_EXTLOAD,
+                             L->getMemoryVT(), L->getChain(),
+                             L->getBasePtr(), L->getOffset(),
+                             L->getSrcValue(), L->getSrcValueOffset(),
+                             L->getMemoryVT(),
+                             L->isVolatile(), L->getAlignment());
+  return BitConvertToInteger(DAG.getNode(ISD::FP_EXTEND, VT, NL));
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatRes_XINT_TO_FP(SDNode *N) {
+  bool isSigned = N->getOpcode() == ISD::SINT_TO_FP;
+  MVT DestVT = N->getValueType(0);
+  SDOperand Op = N->getOperand(0);
+
+  if (Op.getValueType() == MVT::i32) {
+    // simple 32-bit [signed|unsigned] integer to float/double expansion
+
+    // Get the stack frame index of a 8 byte buffer.
+    SDOperand StackSlot = DAG.CreateStackTemporary(MVT::f64);
+
+    // word offset constant for Hi/Lo address computation
+    SDOperand Offset =
+      DAG.getConstant(MVT(MVT::i32).getSizeInBits() / 8,
+                      TLI.getPointerTy());
+    // set up Hi and Lo (into buffer) address based on endian
+    SDOperand Hi = StackSlot;
+    SDOperand Lo = DAG.getNode(ISD::ADD, TLI.getPointerTy(), StackSlot, Offset);
+    if (TLI.isLittleEndian())
+      std::swap(Hi, Lo);
+
+    // if signed map to unsigned space
+    SDOperand OpMapped;
+    if (isSigned) {
+      // constant used to invert sign bit (signed to unsigned mapping)
+      SDOperand SignBit = DAG.getConstant(0x80000000u, MVT::i32);
+      OpMapped = DAG.getNode(ISD::XOR, MVT::i32, Op, SignBit);
+    } else {
+      OpMapped = Op;
+    }
+    // store the lo of the constructed double - based on integer input
+    SDOperand Store1 = DAG.getStore(DAG.getEntryNode(),
+                                    OpMapped, Lo, NULL, 0);
+    // initial hi portion of constructed double
+    SDOperand InitialHi = DAG.getConstant(0x43300000u, MVT::i32);
+    // store the hi of the constructed double - biased exponent
+    SDOperand Store2=DAG.getStore(Store1, InitialHi, Hi, NULL, 0);
+    // load the constructed double
+    SDOperand Load = DAG.getLoad(MVT::f64, Store2, StackSlot, NULL, 0);
+    // FP constant to bias correct the final result
+    SDOperand Bias = DAG.getConstantFP(isSigned ?
+                                            BitsToDouble(0x4330000080000000ULL)
+                                          : BitsToDouble(0x4330000000000000ULL),
+                                     MVT::f64);
+    // subtract the bias
+    SDOperand Sub = DAG.getNode(ISD::FSUB, MVT::f64, Load, Bias);
+    // final result
+    SDOperand Result;
+    // handle final rounding
+    if (DestVT == MVT::f64) {
+      // do nothing
+      Result = Sub;
+    } else if (DestVT.bitsLT(MVT::f64)) {
+      Result = DAG.getNode(ISD::FP_ROUND, DestVT, Sub,
+                           DAG.getIntPtrConstant(0));
+    } else if (DestVT.bitsGT(MVT::f64)) {
+      Result = DAG.getNode(ISD::FP_EXTEND, DestVT, Sub);
+    }
+    return BitConvertToInteger(Result);
+  }
+  assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
+  SDOperand Tmp1 = DAG.getNode(ISD::SINT_TO_FP, DestVT, Op);
+
+  SDOperand SignSet = DAG.getSetCC(TLI.getSetCCResultType(Op), Op,
+                                   DAG.getConstant(0, Op.getValueType()),
+                                   ISD::SETLT);
+  SDOperand Zero = DAG.getIntPtrConstant(0), Four = DAG.getIntPtrConstant(4);
+  SDOperand CstOffset = DAG.getNode(ISD::SELECT, Zero.getValueType(),
+                                    SignSet, Four, Zero);
+
+  // If the sign bit of the integer is set, the large number will be treated
+  // as a negative number.  To counteract this, the dynamic code adds an
+  // offset depending on the data type.
+  uint64_t FF;
+  switch (Op.getValueType().getSimpleVT()) {
+  default: assert(0 && "Unsupported integer type!");
+  case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
+  case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
+  case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
+  case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
+  }
+  if (TLI.isLittleEndian()) FF <<= 32;
+  static Constant *FudgeFactor = ConstantInt::get(Type::Int64Ty, FF);
+
+  SDOperand CPIdx = DAG.getConstantPool(FudgeFactor, TLI.getPointerTy());
+  CPIdx = DAG.getNode(ISD::ADD, TLI.getPointerTy(), CPIdx, CstOffset);
+  SDOperand FudgeInReg;
+  if (DestVT == MVT::f32)
+    FudgeInReg = DAG.getLoad(MVT::f32, DAG.getEntryNode(), CPIdx,
+                             PseudoSourceValue::getConstantPool(), 0);
+  else {
+    FudgeInReg = DAG.getExtLoad(ISD::EXTLOAD, DestVT,
+                                DAG.getEntryNode(), CPIdx,
+                                PseudoSourceValue::getConstantPool(), 0,
+                                MVT::f32);
+  }
+
+  return BitConvertToInteger(DAG.getNode(ISD::FADD, DestVT, Tmp1, FudgeInReg));
+}
+
+
+//===----------------------------------------------------------------------===//
+//  Operand Float to Integer Conversion..
+//===----------------------------------------------------------------------===//
+
+bool DAGTypeLegalizer::PromoteFloatOperand(SDNode *N, unsigned OpNo) {
+  DEBUG(cerr << "Promote float operand " << OpNo << ": "; N->dump(&DAG);
+        cerr << "\n");
+  SDOperand Res(0, 0);
+
+  // FIXME: Custom lowering for float-to-int?
+#if 0
+  if (TLI.getOperationAction(N->getOpcode(), N->getOperand(OpNo).getValueType())
+      == TargetLowering::Custom)
+    Res = TLI.LowerOperation(SDOperand(N, 0), DAG);
+#endif
+
+  if (Res.Val == 0) {
+    switch (N->getOpcode()) {
+    default:
+#ifndef NDEBUG
+      cerr << "PromoteFloatOperand Op #" << OpNo << ": ";
+      N->dump(&DAG); cerr << "\n";
+#endif
+      assert(0 && "Do not know how to convert this operator's operand!");
+      abort();
+
+      case ISD::BIT_CONVERT: Res = PromoteFloatOp_BIT_CONVERT(N); break;
+    }
+  }
+
+  // If the result is null, the sub-method took care of registering results etc.
+  if (!Res.Val) return false;
+
+  // If the result is N, the sub-method updated N in place.  Check to see if any
+  // operands are new, and if so, mark them.
+  if (Res.Val == N) {
+    // Mark N as new and remark N and its operands.  This allows us to correctly
+    // revisit N if it needs another step of promotion and allows us to visit
+    // any new operands to N.
+    ReanalyzeNode(N);
+    return true;
+  }
+
+  assert(Res.getValueType() == N->getValueType(0) && N->getNumValues() == 1 &&
+         "Invalid operand expansion");
+
+  ReplaceValueWith(SDOperand(N, 0), Res);
+  return false;
+}
+
+SDOperand DAGTypeLegalizer::PromoteFloatOp_BIT_CONVERT(SDNode *N) {
+  return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0),
+                     GetPromotedFloat(N->getOperand(0)));
+}
+
+
+//===----------------------------------------------------------------------===//
+//  Float Result Expansion
+//===----------------------------------------------------------------------===//
+
+/// ExpandFloatResult - This method is called when the specified result of the
+/// specified node is found to need expansion.  At this point, the node may also
+/// have invalid operands or may have other results that need promotion, we just
+/// know that (at least) one result needs expansion.
+void DAGTypeLegalizer::ExpandFloatResult(SDNode *N, unsigned ResNo) {
+  DEBUG(cerr << "Expand float result: "; N->dump(&DAG); cerr << "\n");
+  SDOperand Lo, Hi;
+  Lo = Hi = SDOperand();
+
+  // See if the target wants to custom expand this node.
+  if (TLI.getOperationAction(N->getOpcode(), N->getValueType(0)) ==
+          TargetLowering::Custom) {
+    // If the target wants to, allow it to lower this itself.
+    if (SDNode *P = TLI.ExpandOperationResult(N, DAG)) {
+      // Everything that once used N now uses P.  We are guaranteed that the
+      // result value types of N and the result value types of P match.
+      ReplaceNodeWith(N, P);
+      return;
+    }
+  }
+
+  switch (N->getOpcode()) {
+  default:
+#ifndef NDEBUG
+    cerr << "ExpandFloatResult #" << ResNo << ": ";
+    N->dump(&DAG); cerr << "\n";
+#endif
+    assert(0 && "Do not know how to expand the result of this operator!");
+    abort();
+  }
+
+  // If Lo/Hi is null, the sub-method took care of registering results etc.
+  if (Lo.Val)
+    SetExpandedFloat(SDOperand(N, ResNo), Lo, Hi);
+}
+
+
+//===----------------------------------------------------------------------===//
+//  Float Operand Expansion
+//===----------------------------------------------------------------------===//
+
+/// ExpandFloatOperand - This method is called when the specified operand of the
+/// specified node is found to need expansion.  At this point, all of the result
+/// types of the node are known to be legal, but other operands of the node may
+/// need promotion or expansion as well as the specified one.
+bool DAGTypeLegalizer::ExpandFloatOperand(SDNode *N, unsigned OpNo) {
+  DEBUG(cerr << "Expand float operand: "; N->dump(&DAG); cerr << "\n");
+  SDOperand Res(0, 0);
+
+  if (TLI.getOperationAction(N->getOpcode(), N->getOperand(OpNo).getValueType())
+      == TargetLowering::Custom)
+    Res = TLI.LowerOperation(SDOperand(N, 0), DAG);
+
+  if (Res.Val == 0) {
+    switch (N->getOpcode()) {
+    default:
+  #ifndef NDEBUG
+      cerr << "ExpandFloatOperand Op #" << OpNo << ": ";
+      N->dump(&DAG); cerr << "\n";
+  #endif
+      assert(0 && "Do not know how to expand this operator's operand!");
+      abort();
+    }
+  }
+
+  // If the result is null, the sub-method took care of registering results etc.
+  if (!Res.Val) return false;
+  // If the result is N, the sub-method updated N in place.  Check to see if any
+  // operands are new, and if so, mark them.
+  if (Res.Val == N) {
+    // Mark N as new and remark N and its operands.  This allows us to correctly
+    // revisit N if it needs another step of expansion and allows us to visit
+    // any new operands to N.
+    ReanalyzeNode(N);
+    return true;
+  }
+
+  assert(Res.getValueType() == N->getValueType(0) && N->getNumValues() == 1 &&
+         "Invalid operand expansion");
+
+  ReplaceValueWith(SDOperand(N, 0), Res);
+  return false;
+}