ggml.c CACHE_LINE_SIZE error: initializer element is not constant

[biemster]

I get this on Ubuntu 18.04 gcc 7.5.0 (time to update, yes), and I don't immediately see how to fix it since I don't know __cpp_lib_hardware_interference_size. Otherwise a simple replacement with a #define would suffice.

gcc -pthread -O3 -mavx -mavx2 -mfma -mf16c -c ggml.c
ggml.c:183:36: error: initializer element is not constant
 const size_t CACHE_LINE_SIZE_F32 = CACHE_LINE_SIZE/sizeof(float);

[biemster]

Also a few

main.cpp:1349:62: sorry, unimplemented: non-trivial designated initializers not supported
             struct ggml_cgraph gf = { .n_threads = n_threads };

so it is really time to update. You can close this if you choose not to support old compilers (although to my defense this is not THAT old..)

[biemster]

Hold on, I'm being to quick here. The initial issue can actually be solved by replacing the const size_t with a #define.

[ggerganov]

Regarding CACHE_LINE_SIZE - we need this to be at least as big as the L1 cache line size to avoid false sharing between threads during computation. I don't see why gcc 7.5.0 thinks this is not constant, but I'm okay to replace it with #define if that solves the issue.

Regarding the designated initializers in the .cpp - just replace it with:

struct ggml_cgraph gf; gf.n_threads = n_threads;

Feel free to submit a PR with these changes and I will be happy to apply them

---

Edit Oct 7:

The suggested fix above is wrong. It should be:

struct ggml_cgraph gf = {}; gf.n_threads = n_threads;

Already fixed on master

[biemster]

Thanks! That works.