-//===-- 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/Module.h"
#include "llvm/DerivedTypes.h"
-#include "llvm/iOther.h"
-#include "llvm/iTerminators.h"
-#include "Support/StatisticReporter.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<>
-NumOversized("bytecodewriter\t- Number of oversized instructions");
+NumHugeOperandInstrs("bytecodewriter", "Number of instructions with > 3 operands");
static Statistic<>
-NumNormal("bytecodewriter\t- Number of normal instructions");
+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;
//
// Format: [opcode] [type] [numargs] [arg0] [arg1] ... [arg<numargs-1>]
//
-static void outputInstructionFormat0(const Instruction *I,
+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(I->getOpcode() << 2, Out); // Instruction Opcode ID
+ output_vbr(Opcode << 2, Out); // Instruction Opcode ID
output_vbr(Type, Out); // Result type
unsigned NumArgs = I->getNumOperands();
- output_vbr(NumArgs + isa<CastInst>(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)) {
- int Slot = Table.getValSlot(I->getType());
+ 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!
- ++NumOversized;
+ BytesOversizedInstrs += Out.size();
}
-// outputInstrVarArgsCall - Output the obsurdly annoying varargs function calls.
+// outputInstrVarArgsCall - Output the absurdly annoying varargs function calls.
// This are more annoying than most because the signature of the call does not
// tell us anything about the types of the arguments in the varargs portion.
// Because of this, we encode (as type 0) all of the argument types explicitly
//
// Format: [opcode] [type] [numargs] [arg0] [arg1] ... [arg<numargs-1>]
//
-static void outputInstrVarArgsCall(const Instruction *I,
+static void outputInstrVarArgsCall(const Instruction *I, unsigned Opcode,
const SlotCalculator &Table, unsigned Type,
std::deque<uchar> &Out) {
assert(isa<CallInst>(I) || isa<InvokeInst>(I));
// Opcode must have top two bits clear...
- output_vbr(I->getOpcode() << 2, Out); // Instruction Opcode ID
+ 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);
}
align32(Out); // We must maintain correct alignment!
- ++NumOversized;
}
// outputInstructionFormat1 - Output one operand instructions, knowing that no
// operand index is >= 2^12.
//
-static void outputInstructionFormat1(const Instruction *I,
+static void outputInstructionFormat1(const Instruction *I, unsigned Opcode,
const SlotCalculator &Table, int *Slots,
unsigned Type, std::deque<uchar> &Out) {
- unsigned Opcode = I->getOpcode(); // Instruction Opcode ID
-
// bits Instruction format:
// --------------------------
// 01-00: Opcode type, fixed to 1.
unsigned Bits = 1 | (Opcode << 2) | (Type << 8) | (Slots[0] << 20);
// cerr << "1 " << IType << " " << Type << " " << Slots[0] << endl;
output(Bits, Out);
- ++NumNormal;
}
// outputInstructionFormat2 - Output two operand instructions, knowing that no
// operand index is >= 2^8.
//
-static void outputInstructionFormat2(const Instruction *I,
+static void outputInstructionFormat2(const Instruction *I, unsigned Opcode,
const SlotCalculator &Table, int *Slots,
unsigned Type, std::deque<uchar> &Out) {
- unsigned Opcode = I->getOpcode(); // Instruction Opcode ID
-
// bits Instruction format:
// --------------------------
// 01-00: Opcode type, fixed to 2.
// cerr << "2 " << IType << " " << Type << " " << Slots[0] << " "
// << Slots[1] << endl;
output(Bits, Out);
- ++NumNormal;
}
// outputInstructionFormat3 - Output three operand instructions, knowing that no
// operand index is >= 2^6.
//
-static void outputInstructionFormat3(const Instruction *I,
+static void outputInstructionFormat3(const Instruction *I, unsigned Opcode,
const SlotCalculator &Table, int *Slots,
unsigned Type, std::deque<uchar> &Out) {
- unsigned Opcode = I->getOpcode(); // Instruction Opcode ID
-
// bits Instruction format:
// --------------------------
// 01-00: Opcode type, fixed to 3.
//cerr << "3 " << IType << " " << Type << " " << Slots[0] << " "
// << Slots[1] << " " << Slots[2] << endl;
output(Bits, Out);
- ++NumNormal;
}
-void BytecodeWriter::processInstruction(const Instruction &I) {
- assert(I.getOpcode() < 64 && "Opcode too big???");
+void BytecodeWriter::outputInstruction(const Instruction &I) {
+ assert(I.getOpcode() < 62 && "Opcode too big???");
+ unsigned Opcode = I.getOpcode();
+
+ // Encode 'volatile load' as 62 and 'volatile store' as 63.
+ if (isa<LoadInst>(I) && cast<LoadInst>(I).isVolatile())
+ Opcode = 62;
+ if (isa<StoreInst>(I) && cast<StoreInst>(I).isVolatile())
+ Opcode = 63;
unsigned NumOperands = I.getNumOperands();
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)) {
+ 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()) {
- outputInstrVarArgsCall(CI, Table, Type, Out);
+ outputInstrVarArgsCall(CI, Opcode, Table, Type, Out);
return;
}
} else if (const InvokeInst *II = dyn_cast<InvokeInst>(&I)) {// ... & Invokes
const PointerType *Ty = cast<PointerType>(II->getCalledValue()->getType());
if (cast<FunctionType>(Ty->getElementType())->isVarArg()) {
- outputInstrVarArgsCall(II, Table, Type, Out);
+ outputInstrVarArgsCall(II, Opcode, Table, Type, Out);
return;
}
}
+ ++NumInstrs;
+
// Decide which instruction encoding to use. This is determined primarily by
// the number of operands, and secondarily by whether or not the max operand
// will fit into the instruction encoding. More operands == fewer bits per
case 0:
case 1:
if (MaxOpSlot < (1 << 12)-1) { // -1 because we use 4095 to indicate 0 ops
- outputInstructionFormat1(&I, Table, Slots, Type, Out);
+ outputInstructionFormat1(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 12)-1)
+ NumOversidedBecauseOfTypes++;
+
+ NumOversized1OpInstrs++;
break;
case 2:
if (MaxOpSlot < (1 << 8)) {
- outputInstructionFormat2(&I, Table, Slots, Type, Out);
+ outputInstructionFormat2(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 8))
+ NumOversidedBecauseOfTypes++;
+ NumOversized2OpInstrs++;
break;
case 3:
if (MaxOpSlot < (1 << 6)) {
- outputInstructionFormat3(&I, Table, Slots, Type, Out);
+ outputInstructionFormat3(&I, Opcode, Table, Slots, Type, Out);
return;
}
+ if (Type >= (1 << 6))
+ NumOversidedBecauseOfTypes++;
+ NumOversized3OpInstrs++;
+ break;
+ default:
+ ++NumHugeOperandInstrs;
break;
}
// If we weren't handled before here, we either have a large number of
- // operands or a large operand index that we are refering to.
- outputInstructionFormat0(&I, Table, Type, Out);
+ // operands or a large operand index that we are referring to.
+ outputInstructionFormat0(&I, Opcode, Table, Type, Out);
}
+