7 Sep
2010
7 Sep
'10
1:36 p.m.
On Tue, 07 Sep 2010 21:06:10 +0800 Yao Qi yao.qi@linaro.org wrote:
Julian Brown wrote:
So yeah, I think there is indeed a possible improvement here (and we don't even need to break the EABI, I don't think). Unless I've overlooked something, anyway...
Julian, I revert back the first example, and add your comments in it. https://wiki.linaro.org/YaoQi/Sandbox/Thumb2SizeOptimize
In order to teach gcc chooses low register when keeping stack alignment, which part of gcc shall I have a look? Is it about RA or regrename?
No, all the code to generate prologues & epilogues is target-specific, and happens after register allocation. Take a look at e.g. arm.c:arm_expand_prologue and friends. (Beware though, they can be quite fiddly!)
Julian