Conditional stack frame allocation
A method for allocating memory includes an operation that determines whether a prototype of a callee function is within a scope of a caller. The caller is a module containing a function call to the callee function. In addition, the method includes determining whether the function call includes one or more unnamed parameters when a prototype of the callee function is within the scope of the caller. Further, the method may include inserting instructions in the caller to allocate a register save area in a memory when it is determined that the function call includes one or more unnamed parameters.
1. A computer-implemented method for allocating memory, comprising:
determining whether a prototype of a callee function is within a scope of a caller, the caller being a module containing a function call to the callee function;
when the prototype of the callee function is not within the scope of the module, inserting instructions in the caller to allocate a register save area in a memory;
when the prototype of the callee function is within the scope of the caller, determining whether the function call includes one or more unnamed parameters;
inserting instructions in the caller to allocate the register save area in the memory when it is determined that the function call includes one or more unnamed parameters;
determining whether all parameters of the function can be passed in registers; and
inserting instructions in the caller to allocate a parameter overflow area in the memory when all parameters of the function call cannot be passed in registers.
2. The method of claim 1 , wherein the inserting of instructions in the caller to allocate a register save area in a memory when it is determined that the function call includes one or more unnamed parameters further comprises:
determining whether all parameters of the function can be passed in registers; and
inserting instructions in the caller to allocate a parameter overflow area in the memory when all parameters of the function call cannot be passed in registers.
3. The method of claim 1 , further comprising:
determining whether all parameters of the function can be passed in registers when it is determined that the function call only includes named parameters; and
omitting instructions in the caller to allocate a register save area in a memory when all parameters of the function call can be passed in registers.
4. The method of claim 1 , further comprising:
determining whether all parameters of the function can be passed in registers when it is determined that the function call only includes named parameters; and
inserting instructions in the caller to allocate a register save area and a parameter overflow area in a memory when all parameters of the function call cannot be passed in registers.
5. The method of claim 1 , wherein the memory is a stack frame of the caller.