Re: [Tinycc-devel] Optimizing code for expressions

[Fabrice Bellard]

Mauro Persano wrote:
> Hi,
>
> I'm wondering if there would be any interest in a modification
> for tcc that would make it keep an expression in a tree in memory
> before generating code. This could allow for some optimizations, 
> such as better constant folding (tcc generates just two 
> multiplications for '5 * 3 * foo', but its single-pass nature 
> prevents it from optimizing 'foo * 5 * 3'), better register 
> allocation, and maybe some common subexpression elimination.
>
> I realize that tcc is (highly) optimized for compiler size and 
> fast compile times, so a modification like this could be viewed as 
> an attempt to steer it away from its original goals. I'm 
> willing to try it, though. Any thoughts?

I would prefer a modification in which the program is transformed in an 
intermediate RISC like machine language. A first step would be to add a 
new target for TCC to generate this RISC like language, and then to 
write the converter to x86 code.

Fabrice.