This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] S/390: Allow to use r2 to r4 as literal pool base.
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>, Ulrich Weigand <Ulrich dot Weigand at de dot ibm dot com>, gcc-patches at gcc dot gnu dot org
- Date: Mon, 21 Dec 2015 13:08:16 +0100
- Subject: Re: [PATCH] S/390: Allow to use r2 to r4 as literal pool base.
- Authentication-results: sourceware.org; auth=none
- References: <20151216135141 dot GA19006 at linux dot vnet dot ibm dot com> <20151216141821 dot B095F1513 at oc7340732750 dot ibm dot com> <20151218102138 dot GA25456 at linux dot vnet dot ibm dot com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Fri, Dec 18, 2015 at 11:21:38AM +0100, Dominik Vogt wrote:
> Latest patch for r2 to r4, including a test case.
> diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
> index ed684af..cba88bb 100644
> --- a/gcc/config/s390/s390.c
> +++ b/gcc/config/s390/s390.c
> @@ -9584,10 +9584,17 @@ s390_init_frame_layout (void)
> as base register to avoid save/restore overhead. */
> if (!base_used)
> cfun->machine->base_reg = NULL_RTX;
> - else if (crtl->is_leaf && !df_regs_ever_live_p (5))
> - cfun->machine->base_reg = gen_rtx_REG (Pmode, 5);
> else
> - cfun->machine->base_reg = gen_rtx_REG (Pmode, BASE_REGNUM);
> + {
> + int br = 0;
> +
> + if (crtl->is_leaf)
> + /* Prefer r5 (most likely to be free). */
> + for (br = 5; br >= 2 && df_regs_ever_live_p (br); br--)
> + ;
> + cfun->machine->base_reg =
> + gen_rtx_REG (Pmode, (br > 0) ? br : BASE_REGNUM);
Note the formatting is wrong. It should be:
cfun->machine->base_reg
= gen_rtx_REG (Pmode, (br > 0) ? br : BASE_REGNUM);
Jakub