> Here are two examples of the challenging RTL instructions: > > (call (mem:QI (symbol_ref:SI (\"stpcpy\") [flags 0x41] <function_decl > 0x401f000 0 __builtin_stpcpy>) [0 S1 A8]) > (const_int 8 [0x8])) > > Q: does this instruction call the function stpcpy or __builtin_stpcpy ?
The compiler will emit a call to stpcpy in the assembly file (modulo further symbol mangling). You cannot really call __builtin_stpcpy anyway since it's a builtin. > (call (mem:QI (symbol_ref:SI (\"check_match.7758\") [flags 0x3] > <function_decl 0x404a3e80 check_match>) [0 S1 A8]) > (const_int 0 [0x0])) > > Q: does this instruction call the function check_match.7758 or check_match > ? Same as above, the pure RTL part gives the symbol name. > In general, why do we have somtimes calls like that which (seemingly) have > different callee targets ? In the former case, because it's a builtin. More generally, the RTL back-end is allowed to mangle symbol names at its pleasure. You can display the RTL associated with a FUNCTION_DECL by invoking debug_tree on it from within GDB. -- Eric Botcazou
