Hi All,
I'm writing a code generation with my compiler. I read sever example and documentation but I did understand what I make wrong.
What I try to do is a compare a local variable with a constant.
But when I create a ICMP instruction I get that instruction are not of same type.
I'm using llvm by svn repository updated at two week ago.
The code that I try to generation is something like:
if varInt = 1 then
varInt := 10;
end_if;
This is my code:
void *visit(integer_c *symbol) {
int64_t value = GET_CVALUE(int64, symbol);
if (typeid(*currentType) == typeid(get_datatype_info_c::bool_type_name)) {
std::cout << "Creating integer: " << value << std::endl;
return (void *)ConstantInt::get(Type::getInt1Ty(getGlobalContext()), value, false);
}
return (void *)ConstantInt::get(Type::getInt16Ty(getGlobalContext()), value, false);
}
void *visit(symbolic_variable_c *symbol) {
std::string varName;
AllocaInst *alloc;
varName = get_var_name_c::get_name(symbol->var_name)->value;
alloc = locals[varName];
return (void *)alloc;
}
void *visit(equ_expression_c *symbol) {
Value *lValue;
Value *rValue;
lValue = (Value *)symbol->l_exp->accept(*this);
rValue = (Value *)symbol->r_exp->accept(*this);
return Builder.CreateICmpEQ (lValue, rValue, "cond");
}
Cheers,
Manuele
you’re not showing enough code. What does accept() do?
Based on your description, I strongly suspect that your alloca and constant are not the same type. Remember that alloca returns a pointer type that you must load to get at the actual variable.
Hi Justin,
my class is a visitor pattern and I use accept method to go recursive in suboject in my AST.
In locals I store AllocaInst pointer.
void *visit(var1_init_decl_c *symbol) {
llvm::Type *lType;
varNames.clear();
varType = "";
symbol->var1_list->accept(*this); /* get a vector contains variable names */
symbol->spec_init->accept(*this); /* Store in varType variable list */
lType = typeOf(varType);
for (unsigned int i = 0; i < varNames.size(); i++) {
AllocaInst *alloc = new AllocaInst(lType, varNames[i].c_str(), currentBBlock);
locals[varNames[i]] = alloc;
}
return NULL;
}
Can I load a AllocaInst using CreateLoad instruction?
Cheers,
Manuele
Hi Justin,
my class is a visitor pattern and I use accept method to go recursive in
suboject in my AST.
In locals I store AllocaInst pointer.
void *visit(var1_init_decl_c *symbol) {
llvm::Type *lType;
varNames.clear();
varType = "";
symbol->var1_list->accept(*this); /* get a vector contains variable names */
symbol->spec_init->accept(*this); /* Store in varType variable list */
lType = typeOf(varType);
for (unsigned int i = 0; i < varNames.size(); i++) {
AllocaInst *alloc = new AllocaInst(lType, varNames[i].c_str(), currentBBlock);
locals[varNames[i]] = alloc;
}
return NULL;
}
Can I load a AllocaInst using CreateLoad instruction?
Yes, your generated alloca is actually returning a "pointer of lType" type.
You need to load the value to an "lType" type. If lType is i32, then
alloca returns an i32*.
Hi Justin,
today I followed your suggestion and it work!!
Many Thanks.
Manuele