Hi, I am thinking (as I am not familiar with IRA) to the following alternative to your solution:
I set to zero all CALL_USED_REGISTERS (except the fixed regs), and then in the expand_call I set CALL_INSN_FUNCTION_USAGE to the list of clobbered registers (given by attribute attached to a function declaration). Then, I should be able to achieve the same effect without touching the IRA. Additionally, a global variable will hold the "default" call_used_registers for the cases when the function call used regs attribute is not set. What do you think about this approach? Best regards, Claudiu
