On Wed, 21 Apr 2021, Jakub Jelinek wrote:
> Hi!
>
> The following testcase shows different behavior between -g and -g0
> in constprop_register, if a flags register setter is separated
> from a conditional jump using those flags with -g by a DEBUG_INSN.
> As it uses just NEXT_INSN, for -g it will look at the DEBUG_INSN which is
> not a conditional jump, while otherwise it would look at the conditional
> jump and call cprop_jump.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk/11.2/10.4?
OK.
Thanks,
Richard.
> 2021-04-20 Jakub Jelinek <ja...@redhat.com>
>
> PR rtl-optimization/100148
> * cprop.c (constprop_register): Use next_nondebug_insn instead of
> NEXT_INSN.
>
> * g++.dg/opt/pr100148.C: New test.
>
> --- gcc/cprop.c.jj 2021-01-04 10:25:39.000000000 +0100
> +++ gcc/cprop.c 2021-04-20 13:48:28.691450016 +0200
> @@ -1007,16 +1007,18 @@ static int
> constprop_register (rtx from, rtx src, rtx_insn *insn)
> {
> rtx sset;
> + rtx_insn *next_insn;
>
> /* Check for reg or cc0 setting instructions followed by
> conditional branch instructions first. */
> if ((sset = single_set (insn)) != NULL
> - && NEXT_INSN (insn)
> - && any_condjump_p (NEXT_INSN (insn)) && onlyjump_p (NEXT_INSN (insn)))
> + && (next_insn = next_nondebug_insn (insn)) != NULL
> + && any_condjump_p (next_insn)
> + && onlyjump_p (next_insn))
> {
> rtx dest = SET_DEST (sset);
> if ((REG_P (dest) || CC0_P (dest))
> - && cprop_jump (BLOCK_FOR_INSN (insn), insn, NEXT_INSN (insn),
> + && cprop_jump (BLOCK_FOR_INSN (insn), insn, next_insn,
> from, src))
> return 1;
> }
> --- gcc/testsuite/g++.dg/opt/pr100148.C.jj 2021-04-20 15:32:31.820489909
> +0200
> +++ gcc/testsuite/g++.dg/opt/pr100148.C 2021-04-20 15:32:06.376770658
> +0200
> @@ -0,0 +1,27 @@
> +// PR rtl-optimization/100148
> +// { dg-do compile }
> +// { dg-options "-O2 -fno-dce -fno-tree-dce -fno-tree-dominator-opts
> -fno-tree-sink -fcompare-debug" }
> +
> +int i;
> +enum E { } e, ee;
> +
> +bool
> +baz (int)
> +{
> + return ee;
> +}
> +
> +bool bar ();
> +bool a, b;
> +
> +void
> +foo ()
> +{
> + switch (ee)
> + {
> + case 0:
> + e = E (a ? : i);
> + case 1:
> + !(b || baz (0) && bar ());
> + }
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
