Initial revision
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Reader/InstructionReader.cpp b/lib/Bytecode/Reader/InstructionReader.cpp
new file mode 100644
index 0000000..667e144
--- /dev/null
+++ b/lib/Bytecode/Reader/InstructionReader.cpp
@@ -0,0 +1,213 @@
+//===- ReadInst.cpp - Code to read an instruction from bytecode -------------===
+//
+// This file defines the mechanism to read an instruction from a bytecode
+// stream.
+//
+// Note that this library should be as fast as possible, reentrant, and
+// threadsafe!!
+//
+// TODO: Change from getValue(Raw.Arg1) etc, to getArg(Raw, 1)
+// Make it check type, so that casts are checked.
+//
+//===------------------------------------------------------------------------===
+
+#include "llvm/iOther.h"
+#include "llvm/iTerminators.h"
+#include "llvm/iMemory.h"
+#include "llvm/DerivedTypes.h"
+#include "ReaderInternals.h"
+
+bool BytecodeParser::ParseRawInst(const uchar *&Buf, const uchar *EndBuf,
+ RawInst &Result) {
+ unsigned Op, Typ;
+ if (read(Buf, EndBuf, Op)) return true;
+
+ Result.NumOperands = Op >> 30;
+ Result.Opcode = (Op >> 24) & 63;
+
+ switch (Result.NumOperands) {
+ case 1:
+ Result.Ty = getType((Op >> 12) & 4095);
+ Result.Arg1 = Op & 4095;
+ if (Result.Arg1 == 4095) // Handle special encoding for 0 operands...
+ Result.NumOperands = 0;
+ break;
+ case 2:
+ Result.Ty = getType((Op >> 16) & 255);
+ Result.Arg1 = (Op >> 8 ) & 255;
+ Result.Arg2 = (Op >> 0 ) & 255;
+ break;
+ case 3:
+ Result.Ty = getType((Op >> 18) & 63);
+ Result.Arg1 = (Op >> 12) & 63;
+ Result.Arg2 = (Op >> 6 ) & 63;
+ Result.Arg3 = (Op >> 0 ) & 63;
+ break;
+ case 0:
+ Buf -= 4; // Hrm, try this again...
+ if (read_vbr(Buf, EndBuf, Result.Opcode)) return true;
+ if (read_vbr(Buf, EndBuf, Typ)) return true;
+ Result.Ty = getType(Typ);
+ if (read_vbr(Buf, EndBuf, Result.NumOperands)) return true;
+
+ switch (Result.NumOperands) {
+ case 0:
+ cerr << "Zero Arg instr found!\n";
+ return true; // This encoding is invalid!
+ case 1:
+ if (read_vbr(Buf, EndBuf, Result.Arg1)) return true;
+ break;
+ case 2:
+ if (read_vbr(Buf, EndBuf, Result.Arg1) ||
+ read_vbr(Buf, EndBuf, Result.Arg2)) return true;
+ break;
+ case 3:
+ if (read_vbr(Buf, EndBuf, Result.Arg1) ||
+ read_vbr(Buf, EndBuf, Result.Arg2) ||
+ read_vbr(Buf, EndBuf, Result.Arg3)) return true;
+ break;
+ default:
+ if (read_vbr(Buf, EndBuf, Result.Arg1) ||
+ read_vbr(Buf, EndBuf, Result.Arg2)) return true;
+
+ // Allocate a vector to hold arguments 3, 4, 5, 6 ...
+ Result.VarArgs = new vector<unsigned>(Result.NumOperands-2);
+ for (unsigned a = 0; a < Result.NumOperands-2; a++)
+ if (read_vbr(Buf, EndBuf, (*Result.VarArgs)[a])) return true;
+ break;
+ }
+ if (align32(Buf, EndBuf)) return true;
+ break;
+ }
+
+ //cerr << "NO: " << Result.NumOperands << " opcode: " << Result.Opcode
+ // << " Ty: " << Result.Ty->getName() << " arg1: " << Result.Arg1 << endl;
+ return false;
+}
+
+
+bool BytecodeParser::ParseInstruction(const uchar *&Buf, const uchar *EndBuf,
+ Instruction *&Res) {
+ RawInst Raw;
+ if (ParseRawInst(Buf, EndBuf, Raw)) return true;;
+
+ if (Raw.Opcode >= Instruction::FirstUnaryOp &&
+ Raw.Opcode < Instruction::NumUnaryOps && Raw.NumOperands == 1) {
+ Res = Instruction::getUnaryOperator(Raw.Opcode, getValue(Raw.Ty, Raw.Arg1));
+ return false;
+ } else if (Raw.Opcode >= Instruction::FirstBinaryOp &&
+ Raw.Opcode < Instruction::NumBinaryOps && Raw.NumOperands == 2) {
+ Res = Instruction::getBinaryOperator(Raw.Opcode, getValue(Raw.Ty, Raw.Arg1),
+ getValue(Raw.Ty, Raw.Arg2));
+ return false;
+ } else if (Raw.Opcode == Instruction::PHINode) {
+ PHINode *PN = new PHINode(Raw.Ty);
+ switch (Raw.NumOperands) {
+ case 0: cerr << "Invalid phi node encountered!\n";
+ delete PN;
+ return true;
+ case 1: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1)); break;
+ case 2: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1));
+ PN->addIncoming(getValue(Raw.Ty, Raw.Arg2)); break;
+ case 3: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1));
+ PN->addIncoming(getValue(Raw.Ty, Raw.Arg2));
+ PN->addIncoming(getValue(Raw.Ty, Raw.Arg3)); break;
+ default:
+ PN->addIncoming(getValue(Raw.Ty, Raw.Arg1));
+ PN->addIncoming(getValue(Raw.Ty, Raw.Arg2));
+ {
+ vector<unsigned> &args = *Raw.VarArgs;
+ for (unsigned i = 0; i < args.size(); i++)
+ PN->addIncoming(getValue(Raw.Ty, args[i]));
+ }
+ delete Raw.VarArgs;
+ }
+ Res = PN;
+ return false;
+ } else if (Raw.Opcode == Instruction::Ret) {
+ if (Raw.NumOperands == 0) {
+ Res = new ReturnInst(); return false;
+ } else if (Raw.NumOperands == 1) {
+ Res = new ReturnInst(getValue(Raw.Ty, Raw.Arg1)); return false;
+ }
+ } else if (Raw.Opcode == Instruction::Br) {
+ if (Raw.NumOperands == 1) {
+ Res = new BranchInst((BasicBlock*)getValue(Type::LabelTy, Raw.Arg1));
+ return false;
+ } else if (Raw.NumOperands == 3) {
+ Res = new BranchInst((BasicBlock*)getValue(Type::LabelTy, Raw.Arg1),
+ (BasicBlock*)getValue(Type::LabelTy, Raw.Arg2),
+ getValue(Type::BoolTy , Raw.Arg3));
+ return false;
+ }
+ } else if (Raw.Opcode == Instruction::Switch) {
+ SwitchInst *I =
+ new SwitchInst(getValue(Raw.Ty, Raw.Arg1),
+ (BasicBlock*)getValue(Type::LabelTy, Raw.Arg2));
+ Res = I;
+ if (Raw.NumOperands < 3) return false; // No destinations? Wierd.
+
+ if (Raw.NumOperands == 3 || Raw.VarArgs->size() & 1) {
+ cerr << "Switch statement with odd number of arguments!\n";
+ delete I;
+ return true;
+ }
+
+ vector<unsigned> &args = *Raw.VarArgs;
+ for (unsigned i = 0; i < args.size(); i += 2)
+ I->dest_push_back((ConstPoolVal*)getValue(Raw.Ty, args[i]),
+ (BasicBlock*)getValue(Type::LabelTy, args[i+1]));
+
+ delete Raw.VarArgs;
+ return false;
+ } else if (Raw.Opcode == Instruction::Call) {
+ Method *M = (Method*)getValue(Raw.Ty, Raw.Arg1);
+ if (M == 0) return true;
+
+ const MethodType::ParamTypes &PL = M->getMethodType()->getParamTypes();
+ MethodType::ParamTypes::const_iterator It = PL.begin();
+
+ vector<Value *> Params;
+ switch (Raw.NumOperands) {
+ case 0: cerr << "Invalid call instruction encountered!\n";
+ return true;
+ case 1: break;
+ case 2: Params.push_back(getValue(*It++, Raw.Arg2)); break;
+ case 3: Params.push_back(getValue(*It++, Raw.Arg2));
+ if (It == PL.end()) return true;
+ Params.push_back(getValue(*It++, Raw.Arg3)); break;
+ default:
+ Params.push_back(getValue(*It++, Raw.Arg2));
+ {
+ vector<unsigned> &args = *Raw.VarArgs;
+ for (unsigned i = 0; i < args.size(); i++) {
+ if (It == PL.end()) return true;
+ Params.push_back(getValue(*It++, args[i]));
+ }
+ }
+ delete Raw.VarArgs;
+ }
+ if (It != PL.end()) return true;
+
+ Res = new CallInst(M, Params);
+ return false;
+ } else if (Raw.Opcode == Instruction::Malloc) {
+ if (Raw.NumOperands > 2) return true;
+ Value *Sz = (Raw.NumOperands == 2) ? getValue(Type::UIntTy, Raw.Arg2) : 0;
+ Res = new MallocInst((ConstPoolType*)getValue(Type::TypeTy, Raw.Arg1), Sz);
+ return false;
+ } else if (Raw.Opcode == Instruction::Alloca) {
+ if (Raw.NumOperands > 2) return true;
+ Value *Sz = (Raw.NumOperands == 2) ? getValue(Type::UIntTy, Raw.Arg2) : 0;
+ Res = new AllocaInst((ConstPoolType*)getValue(Type::TypeTy, Raw.Arg1), Sz);
+ return false;
+ } else if (Raw.Opcode == Instruction::Free) {
+ Value *Val = getValue(Raw.Ty, Raw.Arg1);
+ if (!Val->getType()->isPointerType()) return true;
+ Res = new FreeInst(Val);
+ return false;
+ }
+
+ cerr << "Unrecognized instruction! " << Raw.Opcode << endl;
+ return true;
+}