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Re: Expansion of memset and memcpy calls.



On 21/10/14 08:37, Ajit Kumar Agarwal wrote:
Hello All:

Memset and Memcpy calls are extensively used in many benchmarks. Inlining or expansion
the memcpy and memset calls improves the performance of many performance
Benchmark.
I have implemented the expansion of strcmp  to the optimizaed sequence of instruction
In open64 compiler for AMD x86 target.

Can I suggest and propose to expand the memset and memcpy calls to the sequence
Of instruction as many targets like ARM are moving implementation of memcpy and
Memset in assembly instead of C. This makes it easier to expand the memcpy and
Memset call in gcc.

There is the 'movmem' standard name that backends can expand to implement memcpy semantics. For aarch64, for example, look at the movmemdi pattern in aarch64.md and the aarch64_expand_movmem helper in aarch64.c

Kyrill


To implement this in GCC we need to expand similarly to the implementation as  builtins.

Let me know what do you think.

Thanks & Regards
Ajit





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