Hello everyone, I am involved in gcc port in which i found the following problem.
Before register renaming pass, callee registers was being used in the body of the code. Hence function prologue saved the register and epilogue restored the register. But register renaming pass removed this particular callee saved register.The output and code generation is proper, but there is an unnecessary save and restore of a callee saved register in the prologue and epilogue even though the reference of the callee saved register has been removed by the renaming pass. I am using the prologue/epilogue patterns instead of the target macros. So is the rename pass allowed to rename a callee saved register? Where might this going wrong? Thanks for you help. Regards, Shafi
