/* Procedure cGen recursively generates code by
* tree traversal
*/
static void cGen( TreeNode * tree)
{ if (tree != NULL)
{ switch (tree->nodekind) {
case StmtK:
genStmt(tree);
break;
case ExpK:
genExp(tree);
break;
default:
break;
}
cGen(tree->sibling);
}
}
static void genExp(TreeNode *tree, TreeType ttype)
{
TreeNode *t1, *t2;
int loc = 0;
int tempvar_loc = 0;
t1 = tree->child[0];
t2 = tree->child[1];
switch (tree->kind.exp)
{
case ConstK:
//emitLOC(REG_EAX, tree->attr.token.val);
break;
case IdK:
//loc = st_lookup(tree->attr.token.stype);
//emitLOV_N(REG_EAX, loc);
break;
case OpK:
genExp(t1, LEFT);
genExp(t2, RIGHT);
switch (t1->kind.exp)
{
case ConstK:
emitLOC(REG_EAX, t1->attr.token.val);
break;
case IdK:
loc = st_lookup(t1->attr.token.stype);
emitLOV_N(REG_EAX, loc);
tempvar_loc = mallocTempVar();
emitMov(REG_EAX, tempvar_loc, VTYPE_TEMP);
break;
case OpK:
break;
}
switch (t2->kind.exp)
{
case ConstK:
emitLOC(REG_EBX, t2->attr.token.val);
break;
case IdK:
loc = st_lookup(t2->attr.token.stype);
emitLOV_N(REG_EBX, loc);
break;
case OpK:
break;
}
switch (ttype)
{
int tempvar_loc;
case ROOT:
switch (tree->attr.token.ttype)
{
case ADD:
emitLOV(REG_EAX, 0, VTYPE_TEMP);
emitLOV(REG_EBX, 1, VTYPE_TEMP);
emitAdd(REG_EBX, REG_EAX);
freeTempVar();
freeTempVar();
break;
case SUB:
break;
case MUL:
emitLOV(REG_EAX, 0, VTYPE_TEMP);
emitLOV(REG_EBX, 1, VTYPE_TEMP);
emitMul(REG_EBX, REG_EAX);
freeTempVar();
freeTempVar();
break;
case DIV:
break;
}
break;
case LEFT:
switch (tree->attr.token.ttype)
{
case ADD:
emitAdd(REG_EBX, REG_EAX);
tempvar_loc = mallocTempVar();
emitMov(REG_EAX, tempvar_loc, VTYPE_TEMP);
break;
case SUB:
break;
case MUL:
emitMul(REG_EBX, REG_EAX);
tempvar_loc = mallocTempVar();
emitMov(REG_EAX, tempvar_loc, VTYPE_TEMP);
break;
case DIV:
break;
}
break;
case RIGHT:
switch (tree->attr.token.ttype)
{
case ADD:
emitAdd(REG_EAX, REG_EBX);
tempvar_loc = mallocTempVar();
emitMov(REG_EBX, tempvar_loc, VTYPE_TEMP);
break;
case SUB:
break;
case MUL:
emitMul(REG_EAX, REG_EBX);
tempvar_loc = mallocTempVar();
emitMov(REG_EBX, tempvar_loc, VTYPE_TEMP);
break;
case DIV:
break;
}
break;
};
break;
}
}
