OrdinaryMagician/vkdoom_m
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- Use a union, rather than pointer aliasing, to access the parts of a VM instruction.

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SVN r1922 (scripting)
This commit is contained in:
Randy Heit 2009-10-17 00:33:23 +00:00
commit e5ef25591d
10 changed files with 171 additions and 154 deletions
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50
src/zscript/vmbuilder.cpp
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@ -39,7 +39,7 @@ VMScriptFunction *VMFunctionBuilder::MakeFunction()
VMScriptFunction *func = new VMScriptFunction;
// Copy code block.
memcpy(func->AllocCode(Code.Size()), &Code[0], Code.Size());
memcpy(func->AllocCode(Code.Size()), &Code[0], Code.Size() * sizeof(VMOP));
// Create constant tables.
if (NumIntConstants > 0)
@ -425,12 +425,6 @@ size_t VMFunctionBuilder::Emit(int opcode, int opa, int opb, int opc)
assert(opa >= 0 && opa <= 255);
assert(opb >= 0 && opb <= 255);
assert(opc >= 0 && opc <= 255);
size_t loc = Code.Reserve(4);
VM_UBYTE *code = &Code[loc];
code[0] = opcode;
code[1] = opa;
code[2] = opb;
code[3] = opc;
if (opcode == OP_PARAM)
{
ParamChange(1);
@ -439,7 +433,12 @@ size_t VMFunctionBuilder::Emit(int opcode, int opa, int opb, int opc)
{
ParamChange(-opb);
}
return loc / 4;
VMOP op;
op.op = opcode;
op.a = opa;
op.b = opb;
op.c = opc;
return Code.Push(op);
}
size_t VMFunctionBuilder::Emit(int opcode, int opa, VM_SHALF opbc)
@ -447,29 +446,25 @@ size_t VMFunctionBuilder::Emit(int opcode, int opa, VM_SHALF opbc)
assert(opcode >= 0 && opcode < NUM_OPS);
assert(opa >= 0 && opa <= 255);
assert(opbc >= -32768 && opbc <= 32767);
size_t loc = Code.Reserve(4);
VM_UBYTE *code = &Code[loc];
code[0] = opcode;
code[1] = opa;
*(VM_SHALF *)&code[2] = opbc;
return loc / 4;
VMOP op;
op.op = opcode;
op.a = opa;
op.i16 = opbc;
return Code.Push(op);
}
size_t VMFunctionBuilder::Emit(int opcode, int opabc)
{
assert(opcode >= 0 && opcode < NUM_OPS);
assert(opabc >= -(1 << 23) && opabc <= (1 << 24) - 1);
size_t loc = Code.Reserve(4);
#ifdef __BIG_ENDIAN__
*(VM_UWORD *)&Code[loc] = (opabc & 0xFFFFFF) | (opcode << 24);
#else
*(VM_UWORD *)&Code[loc] = opcode | (opabc << 8);
#endif
if (opcode == OP_PARAMI)
{
ParamChange(1);
}
return loc / 4;
VMOP op;
op.op = opcode;
op.i24 = opabc;
return Code.Push(op);
}
//==========================================================================
@ -504,14 +499,11 @@ size_t VMFunctionBuilder::EmitLoadInt(int regnum, int value)
void VMFunctionBuilder::Backpatch(size_t loc, size_t target)
{
assert(loc < Code.Size() / 4);
assert(loc < Code.Size());
int offset = int(target - loc - 1);
assert(offset >= -(1 << 24) && offset <= (1 << 24) - 1);
#ifdef __BIG_ENDIAN__
*(VM_UWORD *)&Code[loc * 4] = (offset & 0xFFFFFF) | (OP_JMP << 24);
#else
*(VM_UWORD *)&Code[loc * 4] = OP_JMP | (offset << 8);
#endif
assert(((offset << 8) >> 8) == offset);
Code[loc].op = OP_JMP;
Code[loc].i24 = offset;
}
//==========================================================================
@ -525,5 +517,5 @@ void VMFunctionBuilder::Backpatch(size_t loc, size_t target)
void VMFunctionBuilder::BackpatchToHere(size_t loc)
{
Backpatch(loc, Code.Size() / 4);
Backpatch(loc, Code.Size());
}