// the classic back patch using the emit functions
int backPatchJumpToHere(int addr, char *comment)
{
int currloc;
currloc = emitSkip(0);
emitBackup(addr);
emitRMAbs((char *)"LDA", PC, currloc, comment);
emitBackup(currloc);
}
void codeGen(TreeNode* currnode)
{
bool texp = false;
while(currnode != NULL)
{
if(currnode->nodekind==DeclK)
{
switch(currnode->kind.decl)
{
case varK:
codeGen(currnode->child[0]);
t2 = (TreeNode*)tab->lookup(currnode->attr.name);
if(t2 == NULL && currnode->isArray)
{
emitRM2((char*)"LDC", AC, currnode->size - 1, AC3, (char*)"load size of array", currnode->attr.name);
emitRM2((char*)"ST", AC, currnode->location + 1, FP, (char*)"save size of array", currnode->attr.name);
}
if(t2 == NULL && currnode->child[0] != NULL)
emitRM2((char*)"ST", AC, currnode->location, FP, (char*)"Store variable", currnode->attr.name);
if(t2 != NULL && currnode->child[0] != NULL)
codeGen(currnode->child[0]);
break;
case paramK:
break;
case funcK:
//printf("test\n");
t1 = (TreeNode*)tab->lookup(currnode->attr.name);
t1->location = emitSkip(0);
currnode->location = t1->location;
toff = 0;
framesize = currnode->size;
//toff = 0 - t1->size;
emitComment2((char*)"BEGIN function", currnode->attr.name);
if(currnode->isPre)
emitRM((char*)"ST", AC, -1, FP, (char*)"Store return address");
else
emitRM((char*)"ST", AC, -1, FP, (char*)"Store return address.");
codeGen(currnode->child[0]);
codeGen(currnode->child[1]);
if(currnode->isPre)
{
switch(currnode->pnum)
{
case 0://input
emitRO((char*)"IN", RT, RT, RT, (char*)"Grab int input");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 1://output
emitRM((char*)"LD", AC, -2, FP, (char*)"Load parameter");
emitRO((char*)"OUT", AC, AC, AC, (char*)"Output integer");
emitRM((char*)"LDC", RT, 0, AC3, (char*)"Set return to 0");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 2://inputb
emitRO((char*)"INB", RT, RT, RT, (char*)"Grab bool input");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 3://ouptutb
emitRM((char*)"LD", AC, -2, FP, (char*)"Load parameter");
emitRO((char*)"OUTB", AC, AC, AC, (char*)"Output bool");
emitRM((char*)"LDC", RT, 0, AC3, (char*)"Set return to 0");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 4://inputc
emitRO((char*)"INC", RT, RT, RT, (char*)"Grab char input");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 5://outputc
emitRM((char*)"LD", AC, -2, FP, (char*)"Load parameter");
emitRO((char*)"OUTC", AC, AC, AC, (char*)"Output char");
emitRM((char*)"LDC", RT, 0, AC3, (char*)"Set return to 0");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case 6://outnl
emitRO((char*)"OUTNL", AC, AC, AC, (char*)"Output a newline");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
}
}
if(!currnode->isPre)
{
emitComment((char*)"Add standard closing in case there is no return statement");
emitRM((char*)"LDC", RT, 0, AC3, (char*)"Set return value to 0");
emitRM((char*)"LD", AC, -1, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, 0, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
}
emitComment2((char*)"END of function", currnode->attr.name);
toff = 0;
break;
}
//in_exp = false;
}
else if(currnode->nodekind==StmtK)
switch(currnode->kind.stmt)
{
case ifK:
int breakk;
int breakk2;
emitComment((char*)"IF");
currloc2 = emitSkip(0);
ifexp = true;
codeGen(currnode->child[0]);
ifexp = false;
emitRM((char*)"JGT", AC, 1, PC, (char*)"Jump to then part");
emitComment((char*)"THEN");
skiploc2 = breakk2;
breakk2 = emitSkip(1);
codeGen(currnode->child[1]);
if(currnode->child[2] != NULL)
{
emitComment((char*)"ELSE");
breakk = emitSkip(1);
backPatchJumpToHere(breakk2, (char*)"Jump around the THEN [backpatch]");
codeGen(currnode->child[2]);
backPatchJumpToHere(breakk, (char*)"Jump around the ELSE [backpatch]");
}
else
backPatchJumpToHere(breakloc, (char*)"Jump around the THEN [backpatch]");
emitComment((char*)"ENDIF");
break;
case returnK:
emitComment((char*)"RETURN");
if (currnode->child[0] != NULL)
{
codeGen(currnode->child[0]); // generate any return value
//t2 = (TreeNode*)tab->lookup(currnode->attr.name);
if(currnode->child[0] != NULL)
{
if(currnode->child[0]->scopeT == local || currnode->child[0]->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[0]->isArray)
{
if(currnode->scopeT == param)
emitRM2((char*)"LD", AC1, currnode->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC, currnode->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRM2((char*)"SUB", AC, AC1, AC, (char*)"Compute offset for", currnode->attr.name);
emitRM2((char*)"LD", AC, 0, AC, (char*)"load the value", currnode->attr.name);
}
emitRM((char*)"LDA", RT, 0, AC, (char*)"Copy result to rt register"); // save in return register
}
// emit return sequence
emitRM((char*)"LD", AC, OFPOFF, FP, (char*)"Load return address");
emitRM((char*)"LD", FP, RETURN_OFFSET, FP, (char*)"Adjust fp");
emitRM((char*)"LDA", PC, 0, AC, (char*)"Return");
break;
case compoundK:
emitComment((char*)"BEGIN compound statement");
codeGen(currnode->child[0]);
codeGen(currnode->child[1]);
emitComment((char*)"END compound statement");
break;
case breakK:
emitComment((char*)"BREAK");
emitRM((char*)"LDA", PC, breakloc - emitSkip(0) - 1, PC, (char*)"break");
break;
case foreachK:
break;
case whileK:
int currloc;
int skiploc;
emitComment((char*)"WHILE");
currloc = emitSkip(0); // save location to return to
codeGen(currnode->child[0]); // generate code for test
emitRM((char*)"JGT", AC, 1, PC, (char*)"Jump to while part"); // test and jump
emitComment((char*)"DO");
skiploc = breakloc; // save the old break statement return point
breakloc = emitSkip(1); // addr of instr that jumps to end of loop
// this is also the backpatch point
codeGen(currnode->child[1]); // generate body of loop
emitRMAbs((char*)"LDA", PC, currloc, (char*)"go to beginning of loop"); // jump to top of loop
backPatchJumpToHere(breakloc, (char*)"No more loop [backpatch]"); // backpatch jump to end of loop at breakloc
breakloc = skiploc; // restore for break statement
emitComment((char*)"ENDWHILE");
break;
}
else if(currnode->nodekind==ExpK)
{
int offReg = 1;
if(!in_exp)
{
emitComment((char*)"EXPRESSION STMT");
in_exp = true;
}
switch(currnode->kind.exp)
{
codeGen(currnode->child[0]);
case opK:
texp = inexp;
inexp = currnode->expType == Bool;
opexp = true;
//tempparam = params;
//params = 1;
codeGen(currnode->child[0]);
opexp = false;
//params = tempparam;
if(currnode->child[1] != NULL)
{
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save left side");
if(!currnode->child[1]->isArray)
codeGen(currnode->child[1]);
else
{
codeGen(currnode->child[1]->child[0]);
t2 = (TreeNode*)tab->lookup(currnode->child[1]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[1]->scopeT == param)
{
if(currnode->child[1]->child[0] != NULL)
emitRM2((char*)"LD", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[1]->attr.name);
else
emitRM2((char*)"LD", AC, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[1]->attr.name);
}
else
{
if(currnode->child[0] != NULL)
{
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Computer offset of value");
emitRM((char*)"LD", AC, 0, AC, (char*)"Load the value");
}
}
}
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Load left into ac1");
}
switch(currnode->attr.op)
{
case ltK:
emitRO((char*)"SUB", AC1, AC1, AC, (char*)"Op <");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
emitRM((char*)"JLT", AC1, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 0, AC3, (char*)"False case");
break;
case gtK:
emitRO((char*)"SUB", AC1, AC1, AC, (char*)"Op <");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
emitRM((char*)"JGT", AC1, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 0, AC3, (char*)"False case");
break;
case equivK:
emitRO((char*)"SUB", AC1, AC1, AC, (char*)"Op ==");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
emitRM((char*)"JEQ", AC1, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 0, AC3, (char*)"False case");
break;
case neqK:
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Op !=");
emitRM((char*)"JEQ", AC, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
break;
case modK:
emitRO((char*)"DIV", AC2, AC1, AC, (char*)"Op %");
emitRO((char*)"MUL", AC2, AC2, AC, (char*)"");
emitRO((char*)"SUB", AC, AC1, AC2, (char*)"");
break;
case UminusK:
emitRM((char*)"LDC", AC1, 0, AC3, (char*)"Load 0");
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Op unary -");
break;
case UmultiK:
emitRO((char*)"MUL", AC, currnode->size + 1, AC, (char*)"Load array size");
break;
case minusK:
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Op -");
break;
case plusK:
emitRO((char*)"ADD", AC, AC1, AC, (char*)"Op +");
break;
case multiK:
emitRO((char*)"MUL", AC, AC1, AC, (char*)"Op *");
break;
case divideK:
emitRO((char*)"DIV", AC, AC1, AC, (char*)"Op /");
break;
case lteqK:
emitRO((char*)"SUB", AC1, AC1, AC, (char*)"Op <=");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
emitRM((char*)"JLE", AC1, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 0, AC3, (char*)"False case");
break;
case gteqK:
emitRO((char*)"SUB", AC1, AC1, AC, (char*)"Op >=");
emitRM((char*)"LDC", AC, 1, AC3, (char*)"True case");
emitRM((char*)"JGE", AC1, 1, PC, (char*)"Jump if true");
emitRM((char*)"LDC", AC, 0, AC3, (char*)"False case");
break;
case notK:
emitRM((char*)"LDA", AC, 1, AC2, (char*)"Not load address");
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Op Not");
break;
case andK:
emitRM((char*)"JEQ", AC, 1, PC, (char*)"Op AND");
emitRM((char*)"LDA", AC, 0, AC2, (char*)"");
break;
case orK:
emitRM((char*)"JEQ", AC, 1, PC, (char*)"Op OR");
emitRM((char*)"LDA", AC, 0, AC2, (char*)"");
break;
}
inexp = texp;
break;
case constK:
if(currnode->expType == Int)
emitRM((char*)"LDC", AC, currnode->attr.val, AC3, (char*)"Load constant");
if(currnode->expType == Bool)
{
if(currnode->attr.bval)
emitRM((char*)"LDC", AC, 1, AC3, (char*)"Load constant");
else
emitRM((char*)"LDC", AC, 0, AC3, (char*)"Load constant");
}
if(currnode->expType == Char)
emitRM((char*)"LDC",AC, currnode->attr.string[1], AC3, (char*)"Load constant");
break;
case idK:
codeGen(currnode->child[0]);
t2 = (TreeNode*)tab->lookup(currnode->attr.name);
if(t2 != NULL)
{
if(currnode->scopeT == local || currnode->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->isArray)
{
if((params != 0 && !inexp) || opexp || ifexp)
{
if(currnode->scopeT == param)
{
//emitRM2((char*)"LD", AC1, currnode->location, FP, (char*)"Load address of base of array", currnode->attr.name);
if(currnode->child[0] != NULL)
emitRM2((char*)"LD", AC1, currnode->location, offReg, (char*)"Load address of base of array", currnode->attr.name);
else
emitRM2((char*)"LD", AC, currnode->location, offReg, (char*)"Load address of base of array", currnode->attr.name);
}
else
{
if(currnode->child[0] != NULL)
emitRM2((char*)"LDA", AC1, currnode->location, offReg, (char*)"Load address of base of array", currnode->attr.name);
else
emitRM2((char*)"LDA", AC, currnode->location, offReg, (char*)"Load address of base of array", currnode->attr.name);
}
if(currnode->child[0] != NULL)
{
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Compute offset of value");
emitRM((char*)"LD", AC, 0, AC, (char*)"load the value");
}
}
//in = true;
}
else if(currnode->scopeT != param && currnode->scopeT != local)
emitRM2((char*)"LD", AC, currnode->location, offReg, (char*)"Load variable", currnode->attr.name);
else
emitRM2((char*)"LD", AC, currnode->location, offReg, (char*)"Load variable", currnode->attr.name);
break;
case assignK:
texp = inexp;
inexp = true;
switch(currnode->attr.op)
{
case peqK:
if(currnode->child[0]->isArray)
{
codeGen(currnode->child[0]);
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save index");
}
codeGen(currnode->child[1]);
t2 = (TreeNode*)tab->lookup(currnode->child[0]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[1]->isArray)
{
if(currnode->child[1]->scopeT == param)
emitRM2((char*)"LD", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Compute offset of value");
emitRM((char*)"LD", AC, 0, AC2, (char*)"Load the value");
}
if(currnode->child[0]->isArray)
{
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Restore index");
if(currnode->child[0]->scopeT == param)
emitRM2((char*)"LD", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC2, AC2, AC1, (char*)"Compute offset of value");
emitRM2((char*)"LD", AC1, 0, AC2, (char*)"loah lhs variable", currnode->child[0]->attr.name);
emitRO((char*)"ADD", AC, AC1, AC, (char*)"op +="); // decrement
emitRM2((char*)"ST", AC, 0, AC2, (char*)"Store variable", currnode->child[0]->attr.name);
}
else
{
emitRM2((char*)"LD", AC1, currnode->child[0]->location, offReg, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRO((char*)"ADD", AC, AC1, AC, (char*)"op +="); // decrement
emitRM2((char*)"ST", AC, currnode->child[0]->location, offReg, (char*)"Store variable", currnode->child[0]->attr.name); // store mutable
}
break;
case meqK:
if(currnode->child[0]->isArray)
{
codeGen(currnode->child[0]);
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save index");
}
codeGen(currnode->child[1]);
t2 = (TreeNode*)tab->lookup(currnode->child[0]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[1]->isArray)
{
if(currnode->child[1]->scopeT == param)
emitRM2((char*)"LD", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Compute offset of value");
emitRM((char*)"LD", AC, 0, AC2, (char*)"Load the value");
}
if(currnode->child[0]->isArray)
{
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Restore index");
if(currnode->child[0]->scopeT == param)
emitRM2((char*)"LD", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC2, AC2, AC1, (char*)"Compute offset of value");
emitRM2((char*)"LD", AC1, 0, AC2, (char*)"loah lhs variable", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC, AC1, AC, (char*)"op -="); // decrement
emitRM2((char*)"ST", AC, 0, AC2, (char*)"Store variable", currnode->child[0]->attr.name);
}
else
{
emitRM2((char*)"LD", AC1, currnode->child[0]->location, offReg, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRO((char*)"SUB", AC, AC1, AC, (char*)"op -="); // decrement
emitRM2((char*)"ST", AC, currnode->child[0]->location, offReg, (char*)"Store variable", currnode->child[0]->attr.name); // store mutable
}
break;
case eqK:
if(currnode->child[0]->isArray)
{
codeGen(currnode->child[0]);
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save index");
}
codeGen(currnode->child[1]);
t2 = (TreeNode*)tab->lookup(currnode->child[0]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[1]->isArray)
{
if(currnode->child[1]->scopeT == param)
emitRM2((char*)"LD", AC1, currnode->child[1]->location, offReg, (char*)"Load address of base of array", currnode->child[1]->attr.name);
else
emitRM2((char*)"LDA", AC1, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC, AC1, AC, (char*)"Compute offset of value");
emitRM((char*)"LD", AC, 0, AC, (char*)"Load the value");
}
if(currnode->child[0]->isArray)
{
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Restore index");
if(currnode->child[0]->scopeT == param)
emitRM2((char*)"LD", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC2, AC2, AC1, (char*)"Compute offset of value");
emitRM2((char*)"ST", AC, 0, AC2, (char*)"Store variable", currnode->child[0]->attr.name);
}
else
emitRM2((char*)"ST", AC, currnode->child[0]->location, offReg, (char*)"Store variable", currnode->child[0]->attr.name);
break;
case ppK:
if(currnode->child[0]->isArray)
{
codeGen(currnode->child[0]);
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save index");
}
//codeGen(currnode->child[0]);
t2 = (TreeNode*)tab->lookup(currnode->child[0]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[0]->isArray)
{
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Restore index");
if(currnode->child[0]->scopeT == param)
emitRM2((char*)"LD", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC2, AC2, AC1, (char*)"Compute offset of the value");
emitRM2((char*)"LD", AC, 0, AC2, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRM2((char*)"LDA", AC, 1, AC, (char*)"increment value of", currnode->child[0]->attr.name); // decrement
emitRM2((char*)"ST", AC, 0, AC2, (char*)"Store variable", currnode->child[0]->attr.name);
}
else
{
emitRM2((char*)"LD", AC, currnode->child[0]->location, offReg, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRM2((char*)"LDA", AC, 1, AC, (char*)"increment value of", currnode->child[0]->attr.name); // decrement
emitRM2((char*)"ST", AC, currnode->child[0]->location, offReg, (char*)"Store variable", currnode->child[0]->attr.name); // store mutable
}
break;
case mmK:
if(currnode->child[0]->isArray)
{
codeGen(currnode->child[0]);
emitRM((char*)"ST", AC, toff-- - framesize, FP, (char*)"Save index");
}
//codeGen(currnode->child[0]);
t2 = (TreeNode*)tab->lookup(currnode->child[0]->attr.name);
if(t2 != NULL)
{
if(t2->scopeT == local || t2->scopeT == param)
offReg = 1;
else
offReg = 0;
}
if(currnode->child[0]->isArray)
{
emitRM((char*)"LD", AC1, ++toff - framesize, FP, (char*)"Restore index");
if(currnode->child[0]->scopeT == param)
emitRM2((char*)"LD", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
else
emitRM2((char*)"LDA", AC2, currnode->child[0]->location, offReg, (char*)"Load address of base of array", currnode->child[0]->attr.name);
emitRO((char*)"SUB", AC2, AC2, AC1, (char*)"Compute offset of the value");
emitRM2((char*)"LD", AC, 0, AC2, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRM2((char*)"LDA", AC, -1, AC, (char*)"increment value of", currnode->child[0]->attr.name); // decrement
emitRM2((char*)"ST", AC, 0, AC2, (char*)"Store variable", currnode->child[0]->attr.name);
}
else
{
emitRM2((char*)"LD", AC, currnode->child[0]->location, offReg, (char*)"load lhs variable", currnode->child[0]->attr.name); // load mutable
emitRM2((char*)"LDA", AC, -1, AC, (char*)"increment value of", currnode->child[0]->attr.name); // decrement
emitRM2((char*)"ST", AC, currnode->child[0]->location, offReg, (char*)"Store variable", currnode->child[0]->attr.name); // store mutable
}
break;
inexp = texp;
}
inexp = false;
break;
case callK:
texp = inexp;
inexp = false;
int ttemp = toff;
TreeNode *tmp = currnode->child[0];
//emitComment((char*)"EXPRESSION STMT");
emitComment2((char*)"\t\t\tBegin call to ", currnode->attr.name);
emitRM((char*)"ST", FP, toff - framesize, 1, (char*)"Store old fp in ghost frame");
toff -= 2;
while(tmp != NULL)
{
params++;
emitComment((char*)"\t\t\tLoad param 1");
codeGen(tmp);
emitRM((char*)"ST", AC, toff-- - framesize,FP, (char*)"Store parameter");
paramoff--;
tmp = tmp->sibling;
params--;
}
toff = ttemp;
paramoff = -2;
//t1 = (TreeNode*)tab->lookup(currnode->attr.name);
emitComment2((char*)"\t\t\tJump to", currnode->attr.name);
emitRM((char*)"LDA", FP, toff - framesize, 1, (char*)"Load address of new frame");
emitRM((char*)"LDA", AC, 1, PC, (char*)"Return address in ac");
//FIX THE DAMN symbtable
TreeNode* t = (TreeNode*)tab->lookup(currnode->attr.name);
emitRM2((char*)"LDA", PC, t->location - emitSkip(0) - 1, PC, (char*)"CALL", t->attr.name);
emitRM((char*)"LDA", AC, 0, RT, (char*)"Save the result in ac");
emitComment2((char*)"\t\t\tEnd call to", currnode->attr.name);
emitComment((char*)"EXPRESSION STMT");
calloff += 2;
inexp = texp;
break;
}//end switch exp
in_exp = false;
}//end expK
//else printf("Unknown node kind");
if(params == 0)
currnode = currnode->sibling;
else
currnode = NULL;
}//end while
}//end function
