-//===-- WriteInst.cpp - Functions for writing instructions -------*- C++ -*--=//
+//===-- InstructionWriter.cpp - Functions for writing instructions --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file implements the routines for encoding instruction opcodes to a
// bytecode stream.
//
-// Note that the performance of this library is not terribly important, because
-// it shouldn't be used by JIT type applications... so it is not a huge focus
-// at least. :)
-//
//===----------------------------------------------------------------------===//
#include "WriterInternals.h"
#include "llvm/Instructions.h"
#include "Support/Statistic.h"
#include <algorithm>
+using namespace llvm;
static Statistic<>
NumInstrs("bytecodewriter", "Number of instructions");
+static Statistic<>
+NumOversizedInstrs("bytecodewriter", "Number of oversized instructions");
+static Statistic<>
+BytesOversizedInstrs("bytecodewriter", "Bytes of oversized instructions");
+
+static Statistic<>
+NumHugeOperandInstrs("bytecodewriter", "Number of instructions with > 3 operands");
+static Statistic<>
+NumOversized1OpInstrs("bytecodewriter", "Number of oversized 1 operand instrs");
+static Statistic<>
+NumOversized2OpInstrs("bytecodewriter", "Number of oversized 2 operand instrs");
+static Statistic<>
+NumOversized3OpInstrs("bytecodewriter", "Number of oversized 3 operand instrs");
+
+static Statistic<>
+NumOversidedBecauseOfTypes("bytecodewriter", "Number of oversized instructions because of their type");
+
typedef unsigned char uchar;
static void outputInstructionFormat0(const Instruction *I, unsigned Opcode,
const SlotCalculator &Table,
unsigned Type, std::deque<uchar> &Out) {
+ NumOversizedInstrs++;
+ BytesOversizedInstrs -= Out.size();
+
// Opcode must have top two bits clear...
output_vbr(Opcode << 2, Out); // Instruction Opcode ID
output_vbr(Type, Out); // Result type
unsigned NumArgs = I->getNumOperands();
- output_vbr(NumArgs + (isa<CastInst>(I) || isa<VarArgInst>(I)), Out);
+ output_vbr(NumArgs + (isa<CastInst>(I) || isa<VANextInst>(I) ||
+ isa<VAArgInst>(I)), Out);
for (unsigned i = 0; i < NumArgs; ++i) {
- int Slot = Table.getValSlot(I->getOperand(i));
+ int Slot = Table.getSlot(I->getOperand(i));
assert(Slot >= 0 && "No slot number for value!?!?");
output_vbr((unsigned)Slot, Out);
}
- if (isa<CastInst>(I) || isa<VarArgInst>(I)) {
- int Slot = Table.getValSlot(I->getType());
- assert(Slot != -1 && "Cast/VarArg return type unknown?");
+ if (isa<CastInst>(I) || isa<VAArgInst>(I)) {
+ int Slot = Table.getSlot(I->getType());
+ assert(Slot != -1 && "Cast return type unknown?");
+ output_vbr((unsigned)Slot, Out);
+ } else if (const VANextInst *VAI = dyn_cast<VANextInst>(I)) {
+ int Slot = Table.getSlot(VAI->getArgType());
+ assert(Slot != -1 && "VarArg argument type unknown?");
output_vbr((unsigned)Slot, Out);
}
align32(Out); // We must maintain correct alignment!
+ BytesOversizedInstrs += Out.size();
}
output_vbr(Opcode << 2, Out); // Instruction Opcode ID
output_vbr(Type, Out); // Result type (varargs type)
- unsigned NumArgs = I->getNumOperands();
- output_vbr(NumArgs*2, Out);
- // TODO: Don't need to emit types for the fixed types of the varargs function
- // prototype...
+ const PointerType *PTy = cast<PointerType>(I->getOperand(0)->getType());
+ const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+ unsigned NumParams = FTy->getNumParams();
+
+ unsigned NumFixedOperands;
+ if (isa<CallInst>(I)) {
+ // Output an operand for the callee and each fixed argument, then two for
+ // each variable argument.
+ NumFixedOperands = 1+NumParams;
+ } else {
+ assert(isa<InvokeInst>(I) && "Not call or invoke??");
+ // Output an operand for the callee and destinations, then two for each
+ // variable argument.
+ NumFixedOperands = 3+NumParams;
+ }
+ output_vbr(2 * I->getNumOperands()-NumFixedOperands, Out);
// The type for the function has already been emitted in the type field of the
// instruction. Just emit the slot # now.
- int Slot = Table.getValSlot(I->getOperand(0));
- assert(Slot >= 0 && "No slot number for value!?!?");
- output_vbr((unsigned)Slot, Out);
-
- // Output a dummy field to fill Arg#2 in the reader that is currently unused
- // for varargs calls. This is a gross hack to make the code simpler, but we
- // aren't really doing very small bytecode for varargs calls anyways.
- // FIXME in the future: Smaller bytecode for varargs calls
- output_vbr(0, Out);
+ for (unsigned i = 0; i != NumFixedOperands; ++i) {
+ int Slot = Table.getSlot(I->getOperand(i));
+ assert(Slot >= 0 && "No slot number for value!?!?");
+ output_vbr((unsigned)Slot, Out);
+ }
- for (unsigned i = 1; i < NumArgs; ++i) {
+ for (unsigned i = NumFixedOperands, e = I->getNumOperands(); i != e; ++i) {
// Output Arg Type ID
- Slot = Table.getValSlot(I->getOperand(i)->getType());
+ int Slot = Table.getSlot(I->getOperand(i)->getType());
assert(Slot >= 0 && "No slot number for value!?!?");
output_vbr((unsigned)Slot, Out);
-
+
// Output arg ID itself
- Slot = Table.getValSlot(I->getOperand(i));
+ Slot = Table.getSlot(I->getOperand(i));
assert(Slot >= 0 && "No slot number for value!?!?");
output_vbr((unsigned)Slot, Out);
}
output(Bits, Out);
}
-void BytecodeWriter::processInstruction(const Instruction &I) {
+void BytecodeWriter::outputInstruction(const Instruction &I) {
assert(I.getOpcode() < 62 && "Opcode too big???");
unsigned Opcode = I.getOpcode();
int MaxOpSlot = 0;
int Slots[3]; Slots[0] = (1 << 12)-1; // Marker to signify 0 operands
- for (unsigned i = 0; i < NumOperands; ++i) {
- const Value *Def = I.getOperand(i);
- int slot = Table.getValSlot(Def);
+ for (unsigned i = 0; i != NumOperands; ++i) {
+ int slot = Table.getSlot(I.getOperand(i));
assert(slot != -1 && "Broken bytecode!");
if (slot > MaxOpSlot) MaxOpSlot = slot;
if (i < 3) Slots[i] = slot;
}
unsigned Type;
- int Slot = Table.getValSlot(Ty);
+ int Slot = Table.getSlot(Ty);
assert(Slot != -1 && "Type not available!!?!");
Type = (unsigned)Slot;
if (Slot > MaxOpSlot) MaxOpSlot = Slot;
// Handle the special case for cast...
- if (isa<CastInst>(I) || isa<VarArgInst>(I)) {
+ if (isa<CastInst>(I) || isa<VAArgInst>(I)) {
// Cast has to encode the destination type as the second argument in the
// packet, or else we won't know what type to cast to!
- Slots[1] = Table.getValSlot(I.getType());
+ Slots[1] = Table.getSlot(I.getType());
assert(Slots[1] != -1 && "Cast return type unknown?");
if (Slots[1] > MaxOpSlot) MaxOpSlot = Slots[1];
NumOperands++;
+ } else if (const VANextInst *VANI = dyn_cast<VANextInst>(&I)) {
+ Slots[1] = Table.getSlot(VANI->getArgType());
+ assert(Slots[1] != -1 && "va_next return type unknown?");
+ if (Slots[1] > MaxOpSlot) MaxOpSlot = Slots[1];
+ NumOperands++;
} else if (const CallInst *CI = dyn_cast<CallInst>(&I)){// Handle VarArg calls
const PointerType *Ty = cast<PointerType>(CI->getCalledValue()->getType());
if (cast<FunctionType>(Ty->getElementType())->isVarArg()) {
outputInstructionFormat1(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 12)-1)
+ NumOversidedBecauseOfTypes++;
+
+ NumOversized1OpInstrs++;
break;
case 2:
outputInstructionFormat2(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 8))
+ NumOversidedBecauseOfTypes++;
+ NumOversized2OpInstrs++;
break;
case 3:
outputInstructionFormat3(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 6))
+ NumOversidedBecauseOfTypes++;
+ NumOversized3OpInstrs++;
+ break;
+ default:
+ ++NumHugeOperandInstrs;
break;
}
// operands or a large operand index that we are referring to.
outputInstructionFormat0(&I, Opcode, Table, Type, Out);
}
+