Commit
8bf0597dde55e4c94a2ff39f1d8130902e3d7a9b (titled as 'Fixed the parser
such that it can read in user defined classes again.') made the parser a bit
slower, especially if the input contains many terms of user-defined type.
The reason for that is quite simple: we throw and catch an exception every
time we construct an object of user-defined type:
// dirty hack to distinguish between serial numbers of functions and real
// pointers.
GiNaC::function* f = NULL;
try {
unsigned serial = (unsigned)(unsigned long)(void *)(reader->second);
f = new GiNaC::function(serial, args);
}
catch ( std::runtime_error ) {
if ( f ) delete f;
ex ret = reader->second(args);
return ret;
}
Fortunately functions are aligned and we can use much more efficient
technique to distinguish between serial and pointers to functions.
#include "power.h"
#include "operators.h"
#include "inifcns.h"
#include "power.h"
#include "operators.h"
#include "inifcns.h"
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#ifdef HAVE_STDINT_H
+#include <stdint.h> // for uintptr_t
+#endif
(format '#f "~{ev[~a]~^, ~}" (sequence 0 (- nargs 1)))) +]);
}[+ ENDFOR +]
(format '#f "~{ev[~a]~^, ~}" (sequence 0 (- nargs 1)))) +]);
}[+ ENDFOR +]
+// function::registered_functions() is protected, but we need to access it
+class registered_functions_hack : public function
+{
+public:
+ static const std::vector<function_options>& get_registered_functions()
+ {
+ return function::registered_functions();
+ }
+private:
+ registered_functions_hack();
+ registered_functions_hack(const registered_functions_hack&);
+ registered_functions_hack& operator=(const registered_functions_hack&);
+};
+
+// Encode an integer into a pointer to a function. Since functions
+// are aligned (the minimal alignment depends on CPU architecture)
+// we can distinguish between pointers and integers.
+static reader_func encode_serial_as_reader_func(unsigned serial)
+{
+ uintptr_t u = (uintptr_t)serial;
+ u = (u << 1) | (uintptr_t)1;
+ reader_func ptr = reinterpret_cast<reader_func>((void *)u);
+ return ptr;
+}
+
const prototype_table& get_default_reader()
{
using std::make_pair;
const prototype_table& get_default_reader()
{
using std::make_pair;
(if (exist? "args") (get "args") "1")
+])] = [+ (get "name") +]_reader;[+
ENDFOR +]
(if (exist? "args") (get "args") "1")
+])] = [+ (get "name") +]_reader;[+
ENDFOR +]
- try {
- for ( unsigned ser=0; ; ++ser ) {
- GiNaC::function f(ser);
- std::string name = f.get_name();
- for ( std::size_t nargs=0; ; ++nargs ) {
- try {
- function::find_function(name, nargs);
- prototype proto = std::pair<std::string, std::size_t>(name, nargs);
- std::pair<prototype_table::iterator, bool> ins = reader.insert(std::pair<prototype,reader_func>(proto, (reader_func)ser));
- if ( ins.second ) break;
- }
- catch ( std::runtime_error ) { }
- }
- }
+ std::vector<function_options>::const_iterator it =
+ registered_functions_hack::get_registered_functions().begin();
+ std::vector<function_options>::const_iterator end =
+ registered_functions_hack::get_registered_functions().end();
+ unsigned serial = 0;
+ for (; it != end; ++it) {
+ prototype proto = make_pair(it->get_name(), it->get_nparams());
+ reader[proto] = encode_serial_as_reader_func(serial);
+ ++serial;
- catch ( std::runtime_error ) { }
initialized = true;
}
return reader;
initialized = true;
}
return reader;
+// <KLUDGE>
+// Find out if ptr is a pointer to a function or a specially crafted integer.
+// It's possible to distinguish between these because functions are aligned.
+// Returns true if ptr is a pointer and false otherwise.
+static bool decode_serial(unsigned& serial, const reader_func ptr)
+{
+ uintptr_t u = (uintptr_t)(void *)ptr;
+ if (u & 1) {
+ u >>= 1;
+ serial = (unsigned)u;
+ return false;
+ }
+ return true;
+}
+
+// Figures out if ptr is a pointer to function or a serial of GiNaC function.
+// In the former case calls that function, in the latter case constructs
+// GiNaC function with corresponding serial and arguments.
+static ex dispatch_reader_fcn(const reader_func ptr, const exvector& args)
+{
+ unsigned serial = 0; // dear gcc, could you please shut up?
+ bool is_ptr = decode_serial(serial, ptr);
+ if (is_ptr)
+ return ptr(args);
+ else
+ return function(serial, args);
+}
+// </KLUDGE>
+
+
/// identifier_expr: identifier | identifier '(' expression* ')'
ex parser::parse_identifier_expr()
{
/// identifier_expr: identifier | identifier '(' expression* ')'
ex parser::parse_identifier_expr()
{
Parse_error_("no function \"" << name << "\" with " <<
args.size() << " arguments");
}
Parse_error_("no function \"" << name << "\" with " <<
args.size() << " arguments");
}
- // dirty hack to distinguish between serial numbers of functions and real
- // pointers.
- GiNaC::function* f = NULL;
- try {
- unsigned serial = (unsigned)(unsigned long)(void *)(reader->second);
- f = new GiNaC::function(serial, args);
- }
- catch ( std::runtime_error ) {
- if ( f ) delete f;
- ex ret = reader->second(args);
- return ret;
- }
- return f->setflag(status_flags::dynallocated);
+ // reader->second might be a pointer to a C++ function or a specially
+ // crafted serial of a GiNaC::function.
+ ex ret = dispatch_reader_fcn(reader->second, args);
+ return ret;
}
/// paren_expr: '(' expression ')'
}
/// paren_expr: '(' expression ')'