66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
Code conventions used internally by fftw3 (not in API):
|
|
|
|
LEARN FROM THE MASTERS: read Ken Thompson's C compiler in Plan 9.
|
|
Avoid learning from C++/Java programs.
|
|
|
|
INDENTATION: K&R, 5 spaces/tab. In case of doubt, indent -kr -i5.
|
|
|
|
NAMES: keep them short. Shorter than you think. The Bible was written
|
|
without vowels. Don't outsmart the Bible.
|
|
|
|
Common names:
|
|
|
|
R : real type, aka fftw_real
|
|
E : real type for local variables (possibly extra precision)
|
|
C : complex type
|
|
sz : size
|
|
vecsz : vector size
|
|
is, os : input/output stride
|
|
ri, ii : real/imag input (complex data)
|
|
ro, io : real/imag output (complex data)
|
|
I, O : real input/output (real data)
|
|
A : assert
|
|
CK : check
|
|
S : solver, defined internally to each solver file
|
|
P : plan, defined internally to each solver file
|
|
k : codelet
|
|
X(...) : used for mangling of external names (see below)
|
|
K(...) : floating-point constant, in E precision
|
|
|
|
If a name is used often and must have the form fftw_foo to avoid
|
|
namespace pollution, #define FOO fftw_foo and use the short name.
|
|
|
|
Leave that hungarian crap to MS. foo_t counts as hungarian: use
|
|
foo instead. foo is lowercase so that it does not look like a DOS
|
|
program. Exception: typedef struct foo_s {...} foo; instead of
|
|
typedef struct foo {...} foo; for C++ compatibility.
|
|
|
|
NAME MANGLING: use X(foo) for external names instead of fftw_foo.
|
|
X(foo) expands to fftwf_foo or fftw_foo, depending on the
|
|
precision. (Unfortunately, this is a ugly form of hungarian
|
|
notation. Grrr...) Names that are not exported do not need to be
|
|
mangled.
|
|
|
|
REPEATED CODE: favor a table. E.g., do not write
|
|
|
|
foo("xxx", 1);
|
|
foo("yyy", 2);
|
|
foo("zzz", -1);
|
|
|
|
Instead write
|
|
|
|
struct { const char *nam, int arg } footab[] = {
|
|
{ "xxx", 1 },
|
|
{ "yyy", 2 },
|
|
{ "zzz", -1 }
|
|
};
|
|
|
|
and loop over footab. Rationale: it saves code space.
|
|
Similarly, replace a switch statement with a table whenever
|
|
possible.
|
|
|
|
C++: The code should compile as a C++ program. Run the code through
|
|
gcc -xc++ . The extra C++ restrictions are unnecessary, of
|
|
course, but this will save us from a flood of complaints when
|
|
we release the code.
|