def handle_prologue(self, func_name, *operands):
"""Handles the prologue of the function definition in IR.
"""
self.memory_offset = 0
# Allocate memory for both the defined variables and the formal parameters.
# Symbol table will have entry for all of them.
for symtab_entry in self.ir.local_symbol_table.values():
if 'memory' in symtab_entry:
symtab_entry['memory'].offset = self.memory_offset
symtab_entry['memory'].size = MEMORY_WIDTH
symtab_entry['memory'].base = 0
self.memory_offset += MEMORY_WIDTH
elif symtab_entry.get('dimensions'):
if 'memory' not in symtab_entry:
symtab_entry['memory'] = Memory()
symtab_entry['memory'].offset = self.memory_offset
total_size = 1
for dimension in symtab_entry['dimensions']:
total_size *= dimension
symtab_entry['memory'].size = total_size * MEMORY_WIDTH
symtab_entry['memory'].base = 0
self.memory_offset += total_size * MEMORY_WIDTH
self.create_stack()
def allocate_global_memory(global_symbol_table):
"""Allocate memory for global datastructures.
Args:
global_symbol_table: Dictionary containing the global symbol table whose
keys are symbol names and values are symbol table data like memory
object for this symbol and type.
"""
memory_offset = 0
for symbol, symtab_entry in global_symbol_table.iteritems():
if symtab_entry.get('type') == 'function_name' or (
symbol in ['InputNum', 'OutputNum', 'OutputNewLine']):
# These symbols are function names, don't do anything for them here.
continue
elif symtab_entry.get('dimensions', None) != None:
# This entry is an array
if 'memory' not in symtab_entry:
symtab_entry['memory'] = Memory()
symtab_entry['memory'].offset = memory_offset
total_size = 1
for dimension in symtab_entry['dimensions']:
total_size *= dimension
symtab_entry['memory'].size = total_size * MEMORY_WIDTH
symtab_entry['memory'].base = 'rip'
memory_offset += total_size * MEMORY_WIDTH
else:
# This entry is a regular integer.
if 'memory' not in symtab_entry:
symtab_entry['memory'] = Memory()
symtab_entry['memory'].offset = memory_offset
symtab_entry['memory'].size = MEMORY_WIDTH
symtab_entry['memory'].base = 'rip'
memory_offset += MEMORY_WIDTH
return memory_offset
