On Tue, Jan 28, 2014 at 11:48 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> I've started an --enable-checking=valgrind bootstrap during the weekend,
> but only on Sunday afternoon and thus killed it on Monday morning, so it
> didn't get very far, but still reported a problem where the build tools
> had uninitialized memory use in copy_rtx:
>     case CLOBBER:
>       /* Share clobbers of hard registers (like cc0), but do not share
>        * pseudo reg
>          clobbers or clobbers of hard registers that originated as pseudos.
>          This is needed to allow safe register renaming.  */
>       if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < 
> FIRST_PSEUDO_REGISTER
>           && ORIGINAL_REGNO (XEXP (orig, 0)) == REGNO (XEXP (orig, 0)))
>         return orig;
> - ORIGINAL_REGNO was uninitialized.  The problem is that read_rtx_code uses
> rtx_alloc, which clears only the first int in the structure (header), and
> then ignores the fields with 0 format character.  For ORIGINAL_REGNO, we
> want to set it to REGNO, for others IMHO it is best to just clear those
> fields.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?

Ok.

Thanks,
Richard.

> 2014-01-28  Jakub Jelinek  <ja...@redhat.com>
>
>         PR other/58712
>         * read-rtl.c (read_rtx_code): Clear all of RTX_CODE_SIZE (code).
>         For REGs set ORIGINAL_REGNO.
>
> --- gcc/read-rtl.c.jj   2014-01-03 11:40:57.000000000 +0100
> +++ gcc/read-rtl.c      2014-01-27 10:01:44.154527266 +0100
> @@ -1131,6 +1131,7 @@ read_rtx_code (const char *code_name)
>    /* If we end up with an insn expression then we free this space below.  */
>    return_rtx = rtx_alloc (code);
>    format_ptr = GET_RTX_FORMAT (code);
> +  memset (return_rtx, 0, RTX_CODE_SIZE (code));
>    PUT_CODE (return_rtx, code);
>
>    if (iterator)
> @@ -1154,6 +1155,8 @@ read_rtx_code (const char *code_name)
>         /* 0 means a field for internal use only.
>            Don't expect it to be present in the input.  */
>        case '0':
> +       if (code == REG)
> +         ORIGINAL_REGNO (return_rtx) = REGNO (return_rtx);
>         break;
>
>        case 'e':
>
>         Jakub

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