[PATCH] Fix trunc_int_for_mode in eliminate_regs_in_insn (PR target/38208)
Richard Guenther
richard.guenther@gmail.com
Fri Nov 21 13:50:00 GMT 2008
On Fri, Nov 21, 2008 at 2:33 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> gcc.c-torture/compile/20080806-1.c now fails on i386 at -O3
> -fomit-frame-pointer -funroll-loops, because gas warns about
> addw $65544, %dx. My memcpy optimization patch just changed what comes up
> from the tree optimizers, but it is correct. But when
> eliminate_regs_in_insn is called on:
>
> (insn:HI 6 5 7 2 20080806-1.c:16 (parallel [
> (set (reg:HI 58 [ pretmp.42 ])
> (plus:HI (subreg:HI (reg/f:SI 20 frame) 0)
> (const_int 136 [0x88])))
> (clobber (reg:CC 17 flags))
> ]) 293 {*addhi_1_lea} (expr_list:REG_UNUSED (reg:CC 17 flags)
> (nil)))
>
> and wants to eliminate (reg:SI 20 frame) for
> (plus:SI (reg:SI sp) (const_int 65408 [0xff80]))
> it adds 136 to 0xff80, but truncates it for SImode (GET_MODE (reg))
> instead of the mode in which the PLUS is performed (HImode,
> GET_MODE (plus_cst_src)). So
> (set (reg:HI 1 dx [orig:58 pretmp.42 ] [58])
> (plus:HI (reg:HI 1 dx [orig:58 pretmp.42 ] [58])
> (const_int 65544 [0x10008])))
> is created, which is of course invalid.
>
> The following patch fixes that, bootstrapped/regtested on x86_64-linux,
> ok for trunk?
Ok.
Thanks,
Richard.
> 2008-11-21 Jakub Jelinek <jakub@redhat.com>
>
> PR target/38208
> * reload1.c (eliminate_regs_in_insn): For trunc_int_for_mode use
> mode of PLUS, not mode of the eliminated register.
>
> --- gcc/reload1.c.jj 2008-10-14 13:58:50.000000000 +0200
> +++ gcc/reload1.c 2008-11-21 09:20:25.000000000 +0100
> @@ -1,6 +1,6 @@
> /* Reload pseudo regs into hard regs for insns that require hard regs.
> Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
> - 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
> + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
> Free Software Foundation, Inc.
>
> This file is part of GCC.
> @@ -3299,7 +3299,7 @@ eliminate_regs_in_insn (rtx insn, int re
> {
> rtx to_rtx = ep->to_rtx;
> offset += ep->offset;
> - offset = trunc_int_for_mode (offset, GET_MODE (reg));
> + offset = trunc_int_for_mode (offset, GET_MODE (plus_cst_src));
>
> if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
> to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
>
> Jakub
>
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