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Re: New target macro HARD_REGNO_CALL_PART_CLOBBERED
- To: Michael Hayes <m dot hayes at elec dot canterbury dot ac dot nz>
- Subject: Re: New target macro HARD_REGNO_CALL_PART_CLOBBERED
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Wed, 30 Sep 1998 18:21:16 -0600
- cc: egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <firstname.lastname@example.org>you write:
> This target macro is used by the register allocator to prevent
> allocation of certain modes in registers which may be clobbered by a
> call. Currently, GCC assumes if a hard register is not a
> call_used_register, then it is fully preserved across a call. This is
> not true with the ABI used by the C4x target, where some registers are
> only partially preserved across a call.
> This patch has no effect on existing targets.
> Sun Sep 27 10:25:18 1998 Michael Hayes <email@example.com>
> * regs.h (HARD_REGNO_CALL_PART_CLOBBERED): New macro.
> * local-alloc.c (find_free_reg): Use it.
> * global.c (find_reg): Likewise.
Is this to deal with the high 8 bits in a 40bit register or something similar?