Hello, I have been trying to implement sibcalls (you can see my digression yesterday in gcc-help) for an arch with gcc 4.3.4. The problem with this is that I only want to sibcall when it happens to reduce my code size.
I noticed (in the internals manual) we cannot actually fallback to a normal call once we decide to sibcall through FUNCTION_OK_FOR_SIBCALL, however, FUNCTION_OK_FOR_SIBCALL is called during expansion which doesn't provide me with as much information as I need to choose between sibcalling or not. The best timing would be when the epilogue is generated, but this doesn't seem possible. One example of the kind of information is if some registers are ever live. This changes in some cases between the expand pass and the pro_and_epilogue pass. As well as the framesize. All of this information is important to have as a precise instrument to decide if sibcall should actually be done. Any suggestion on how to achieve this? -- Paulo Jorge Matos - pocmatos at gmail.com http://www.pmatos.net
