More Weirdness

[R.D. Silverman]

It's heavy mystery time. Under Linux gcc I have:


#define T 15
#define K 32

printf("%d %d %d %d\n", T, K, T*K, (T)*(K) );


yields

15 32 108 480

!!!!!!!

What is the preprocessor doing??? Why is it misinterpreting T*K?
and furthermore..... how is it misinterpreting it??????

[jrk]

I get: 15 32 480 480

Which version of GCC?

gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC)

edit: also tried gcc version 3.4.6 20060404 (Red Hat 3.4.6-9) and it still works.

[ldesnogu]

Originally Posted by R.D. Silverman

What is the preprocessor doing??? Why is it misinterpreting T*K?
and furthermore..... how is it misinterpreting it??????

If you think your preprocessor is playing tricks on you, you can try gcc -E, which will produce a file after preprocessing has been done.

[grandpascorpion]

Why not use const int rather than define?

[CRGreathouse]

Originally Posted by grandpascorpion

Why not use const int rather than define?

I imagine he's more interested in giving us a minimal example displaying the (bug? weirdness?) he's found than anything else.