[llvm-commits] CVS: llvm/lib/Target/Sparc/SparcInstrSelection.cpp
Vikram Adve
vadve at cs.uiuc.edu
Fri Sep 27 09:34:00 PDT 2002
Changes in directory llvm/lib/Target/Sparc:
SparcInstrSelection.cpp updated: 1.72 -> 1.73
---
Log message:
Overhaul integer conversions to match C++ ISO standard.
Don't allow direct FP-to-uint conversion (must be eliminated by preselection).
Address arithmetic for arrays is now entirely 64-bit so no sign-ext needed.
---
Diffs of the changes:
Index: llvm/lib/Target/Sparc/SparcInstrSelection.cpp
diff -u llvm/lib/Target/Sparc/SparcInstrSelection.cpp:1.72 llvm/lib/Target/Sparc/SparcInstrSelection.cpp:1.73
--- llvm/lib/Target/Sparc/SparcInstrSelection.cpp:1.72 Mon Sep 16 10:56:45 2002
+++ llvm/lib/Target/Sparc/SparcInstrSelection.cpp Fri Sep 27 09:33:08 2002
@@ -268,43 +268,38 @@
}
static inline MachineOpCode
-ChooseConvertToIntInstr(Type::PrimitiveID tid, const Type* opType)
+ChooseConvertFPToIntInstr(Type::PrimitiveID tid, const Type* opType)
{
MachineOpCode opCode = INVALID_OPCODE;;
-
- if (tid==Type::SByteTyID || tid==Type::ShortTyID || tid==Type::IntTyID ||
- tid==Type::UByteTyID || tid==Type::UShortTyID || tid==Type::UIntTyID)
+
+ assert((opType == Type::FloatTy || opType == Type::DoubleTy)
+ && "This function should only be called for FLOAT or DOUBLE");
+
+ if (tid==Type::UIntTyID)
{
- switch (opType->getPrimitiveID())
- {
- case Type::FloatTyID: opCode = FSTOI; break;
- case Type::DoubleTyID: opCode = FDTOI; break;
- default:
- assert(0 && "Non-numeric non-bool type cannot be converted to Int");
- break;
- }
+ assert(tid != Type::UIntTyID && "FP-to-uint conversions must be expanded"
+ " into FP->long->uint for SPARC v9: SO RUN PRESELECTION PASS!");
+ }
+ else if (tid==Type::SByteTyID || tid==Type::ShortTyID || tid==Type::IntTyID ||
+ tid==Type::UByteTyID || tid==Type::UShortTyID)
+ {
+ opCode = (opType == Type::FloatTy)? FSTOI : FDTOI;
}
else if (tid==Type::LongTyID || tid==Type::ULongTyID)
{
- switch (opType->getPrimitiveID())
- {
- case Type::FloatTyID: opCode = FSTOX; break;
- case Type::DoubleTyID: opCode = FDTOX; break;
- default:
- assert(0 && "Non-numeric non-bool type cannot be converted to Long");
- break;
- }
+ opCode = (opType == Type::FloatTy)? FSTOX : FDTOX;
}
else
assert(0 && "Should not get here, Mo!");
-
+
return opCode;
}
MachineInstr*
-CreateConvertToIntInstr(Type::PrimitiveID destTID, Value* srcVal,Value* destVal)
+CreateConvertFPToIntInstr(Type::PrimitiveID destTID,
+ Value* srcVal, Value* destVal)
{
- MachineOpCode opCode = ChooseConvertToIntInstr(destTID, srcVal->getType());
+ MachineOpCode opCode = ChooseConvertFPToIntInstr(destTID, srcVal->getType());
assert(opCode != INVALID_OPCODE && "Expected to need conversion!");
MachineInstr* M = new MachineInstr(opCode);
@@ -348,8 +343,8 @@
mcfi.addTemp(destForCast);
// Create the fp-to-int conversion code
- MachineInstr* M = CreateConvertToIntInstr(destI->getType()->getPrimitiveID(),
- opVal, destForCast);
+ MachineInstr* M =CreateConvertFPToIntInstr(destI->getType()->getPrimitiveID(),
+ opVal, destForCast);
mvec.push_back(M);
// Create the fpreg-to-intreg copy code
@@ -540,7 +535,6 @@
// of dest, so we need to put the result of the SLL into a temporary.
//
Value* shiftDest = destVal;
- const Type* opType = argVal1->getType();
unsigned opSize = target.DataLayout.getTypeSize(argVal1->getType());
if ((shiftOpCode == SLL || shiftOpCode == SLLX)
&& opSize < target.DataLayout.getIntegerRegize())
@@ -558,8 +552,8 @@
{ // extend the sign-bit of the result into all upper bits of dest
assert(8*opSize <= 32 && "Unexpected type size > 4 and < IntRegSize?");
target.getInstrInfo().
- CreateSignExtensionInstructions(target, F, shiftDest, 8*opSize,
- destVal, mvec, mcfi);
+ CreateSignExtensionInstructions(target, F, shiftDest, destVal,
+ 8*opSize, mvec, mcfi);
}
}
@@ -1000,7 +994,7 @@
Value* idxVal = idxVec[firstIdxIsZero];
vector<MachineInstr*> mulVec;
- Instruction* addr = new TmpInstruction(Type::UIntTy, memInst);
+ Instruction* addr = new TmpInstruction(Type::ULongTy, memInst);
MachineCodeForInstruction::get(memInst).addTemp(addr);
// Get the array type indexed by idxVal, and compute its element size.
@@ -1024,9 +1018,6 @@
MachineCodeForInstruction::get(memInst),
INVALID_MACHINE_OPCODE);
- // Sign-extend the result of MUL from 32 to 64 bits.
- target.getInstrInfo().CreateSignExtensionInstructions(target, memInst->getParent()->getParent(), addr, /*srcSizeInBits*/32, addr, mulVec, MachineCodeForInstruction::get(memInst));
-
// Insert mulVec[] before *mvecI in mvec[] and update mvecI
// to point to the same instruction it pointed to before.
assert(mulVec.size() > 0 && "No multiply code created?");
@@ -1446,29 +1437,64 @@
}
case 23: // reg: ToUByteTy(reg)
+ case 24: // reg: ToSByteTy(reg)
case 25: // reg: ToUShortTy(reg)
+ case 26: // reg: ToShortTy(reg)
case 27: // reg: ToUIntTy(reg)
- case 29: // reg: ToULongTy(reg)
+ case 28: // reg: ToIntTy(reg)
{
+ //======================================================================
+ // Rules for integer conversions:
+ //
+ //--------
+ // From ISO 1998 C++ Standard, Sec. 4.7:
+ //
+ // 2. If the destination type is unsigned, the resulting value is
+ // the least unsigned integer congruent to the source integer
+ // (modulo 2n where n is the number of bits used to represent the
+ // unsigned type). [Note: In a two s complement representation,
+ // this conversion is conceptual and there is no change in the
+ // bit pattern (if there is no truncation). ]
+ //
+ // 3. If the destination type is signed, the value is unchanged if
+ // it can be represented in the destination type (and bitfield width);
+ // otherwise, the value is implementation-defined.
+ //--------
+ //
+ // Since we assume 2s complement representations, this implies:
+ //
+ // -- if operand is smaller than destination, zero-extend or sign-extend
+ // according to the signedness of the *operand*: source decides.
+ // ==> we have to do nothing here!
+ //
+ // -- if operand is same size as or larger than destination, and the
+ // destination is *unsigned*, zero-extend the operand: dest. decides
+ //
+ // -- if operand is same size as or larger than destination, and the
+ // destination is *signed*, the choice is implementation defined:
+ // we sign-extend the operand: i.e., again dest. decides.
+ // Note: this matches both Sun's cc and gcc3.2.
+ //======================================================================
+
Instruction* destI = subtreeRoot->getInstruction();
Value* opVal = subtreeRoot->leftChild()->getValue();
- const Type* opType = subtreeRoot->leftChild()->getValue()->getType();
+ const Type* opType = opVal->getType();
if (opType->isIntegral() || isa<PointerType>(opType))
{
unsigned opSize = target.DataLayout.getTypeSize(opType);
unsigned destSize = target.DataLayout.getTypeSize(destI->getType());
- if (opSize > destSize ||
- (opType->isSigned()
- && destSize < target.DataLayout.getIntegerRegize()))
- { // operand is larger than dest,
- // OR both are equal but smaller than the full register size
- // AND operand is signed, so it may have extra sign bits:
- // mask high bits using AND
- M = Create3OperandInstr(AND, opVal,
- ConstantUInt::get(Type::ULongTy,
- ((uint64_t) 1 << 8*destSize) - 1),
- destI);
- mvec.push_back(M);
+ if (opSize >= destSize)
+ { // Operand is same size as or larger than dest:
+ // zero- or sign-extend, according to the signeddness of
+ // the destination (see above).
+ if (destI->getType()->isSigned())
+ target.getInstrInfo().CreateSignExtensionInstructions(target,
+ destI->getParent()->getParent(), opVal, destI, 8*destSize,
+ mvec, MachineCodeForInstruction::get(destI));
+ else
+ target.getInstrInfo().CreateZeroExtensionInstructions(target,
+ destI->getParent()->getParent(), opVal, destI, 8*destSize,
+ mvec, MachineCodeForInstruction::get(destI));
}
else
forwardOperandNum = 0; // forward first operand to user
@@ -1477,69 +1503,33 @@
{
CreateCodeToConvertFloatToInt(target, opVal, destI, mvec,
MachineCodeForInstruction::get(destI));
- maskUnsignedResult = true; // not handled by convert code
+ if (destI->getType()->isUnsigned())
+ maskUnsignedResult = true; // not handled by fp->int code
}
else
assert(0 && "Unrecognized operand type for convert-to-unsigned");
break;
}
-
- case 24: // reg: ToSByteTy(reg)
- case 26: // reg: ToShortTy(reg)
- case 28: // reg: ToIntTy(reg)
+
+ case 29: // reg: ToULongTy(reg)
case 30: // reg: ToLongTy(reg)
{
- Instruction* destI = subtreeRoot->getInstruction();
Value* opVal = subtreeRoot->leftChild()->getValue();
- MachineCodeForInstruction& mcfi =MachineCodeForInstruction::get(destI);
-
const Type* opType = opVal->getType();
if (opType->isIntegral() || isa<PointerType>(opType))
+ forwardOperandNum = 0; // forward first operand to user
+ else if (opType->isFloatingPoint())
{
- // These operand types have the same format as the destination,
- // but may have different size: add sign bits or mask as needed.
- //
- const Type* destType = destI->getType();
- unsigned opSize = target.DataLayout.getTypeSize(opType);
- unsigned destSize = target.DataLayout.getTypeSize(destType);
-
- if (opSize < destSize ||
- (opSize == destSize &&
- opSize == target.DataLayout.getIntegerRegize()))
- { // operand is smaller or both operand and result fill register
- forwardOperandNum = 0; // forward first operand to user
- }
- else
- { // need to mask (possibly) and then sign-extend (definitely)
- Value* srcForSignExt = opVal;
- unsigned srcSizeForSignExt = 8 * opSize;
- if (opSize > destSize)
- { // operand is larger than dest: mask high bits
- TmpInstruction *tmpI = new TmpInstruction(destType, opVal,
- destI, "maskHi");
- mcfi.addTemp(tmpI);
- M = Create3OperandInstr(AND, opVal,
- ConstantUInt::get(Type::ULongTy,
- ((uint64_t) 1 << 8*destSize)-1),
- tmpI);
- mvec.push_back(M);
- srcForSignExt = tmpI;
- srcSizeForSignExt = 8 * destSize;
- }
-
- // sign-extend
- target.getInstrInfo().CreateSignExtensionInstructions(target, destI->getParent()->getParent(), srcForSignExt, srcSizeForSignExt, destI, mvec, mcfi);
- }
+ Instruction* destI = subtreeRoot->getInstruction();
+ CreateCodeToConvertFloatToInt(target, opVal, destI, mvec,
+ MachineCodeForInstruction::get(destI));
}
- else if (opType->isFloatingPoint())
- CreateCodeToConvertFloatToInt(target, opVal, destI, mvec, mcfi);
else
assert(0 && "Unrecognized operand type for convert-to-signed");
-
break;
- }
-
+ }
+
case 31: // reg: ToFloatTy(reg):
case 32: // reg: ToDoubleTy(reg):
case 232: // reg: ToDoubleTy(Constant):
@@ -1600,7 +1590,7 @@
}
else
srcForCast = leftVal;
-
+
M = new MachineInstr(opCode);
M->SetMachineOperandVal(0, MachineOperand::MO_VirtualRegister,
srcForCast);
@@ -2174,7 +2164,7 @@
for (unsigned i=0, N=mvec.size(); i < N; ++i)
mvec[i]->substituteValue(dest, tmpI);
- M = Create3OperandInstr_UImmed(SRL, tmpI, 4-destSize, dest);
+ M = Create3OperandInstr_UImmed(SRL, tmpI, 8*(4-destSize), dest);
mvec.push_back(M);
}
else if (destSize < target.DataLayout.getIntegerRegize())
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