On December 10, 2015 9:11:16 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
wrote:
>Hi!
>
>It seems some passes in between the combiner and ira aren't prepared to
>update dominance info. It usually is not a problem, because already
>before
>the combiner we call free_dominance_info. But we now have a new i?86
>stv pass that is injected after the combiner that computes dominators
>but
>does not free them.
>
>So, to fix ICE on the following testcase, we can either do what the
>patch
>does, or could conditionalize both the calculate_dominance_info and
>free_dominance_info in the convert_scalars_to_vector function (stv
>pass)
>on the dominance info not being computed (like other places in gcc do),
>or we could stick free_dominance_info into all passes that break the
>dominators just in case it would be computed (out_of_cfglayout is one
>example).
We rely on this everywhere else so that would be preferred.
Richard.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, is this ok for
>trunk
>(or some other variant is preferrable)?
>
>2015-12-10 Jakub Jelinek <ja...@redhat.com>
>
> PR rtl-optimization/68730
> * config/i386/i386.c (convert_scalars_to_vector): Call
> free_dominance_info at the end.
>
> * gcc.dg/pr68730.c: New test.
>
>--- gcc/config/i386/i386.c.jj 2015-12-09 14:39:02.000000000 +0100
>+++ gcc/config/i386/i386.c 2015-12-10 12:15:59.517609392 +0100
>@@ -3577,6 +3577,7 @@ convert_scalars_to_vector ()
> BITMAP_FREE (candidates);
> bitmap_obstack_release (NULL);
> df_process_deferred_rescans ();
>+ free_dominance_info (CDI_DOMINATORS);
>
> /* Conversion means we may have 128bit register spills/fills
> which require aligned stack. */
>--- gcc/testsuite/gcc.dg/pr68730.c.jj 2015-12-10 12:22:07.330365019
>+0100
>+++ gcc/testsuite/gcc.dg/pr68730.c 2015-12-10 12:24:03.908702426 +0100
>@@ -0,0 +1,51 @@
>+/* PR rtl-optimization/68730 */
>+/* { dg-do compile } */
>+/* { dg-options "-O3 -fno-if-conversion" } */
>+/* { dg-additional-options "-march=x86-64" { target { i?86-*-*
>x86_64-*-* } } } */
>+
>+int b, d, e;
>+unsigned long long c = 4100543410106915;
>+
>+void
>+foo (void)
>+{
>+ short f, g = 4 % c;
>+ int h = c;
>+ if (h)
>+ {
>+ int i = ~c;
>+ if (~c)
>+ i = 25662;
>+ f = g = i;
>+ h = c - g + ~-f;
>+ c = ~(c * h - f);
>+ }
>+ f = g;
>+ unsigned long long k = g || c;
>+ short l = c ^ g ^ k;
>+ if (g > 25662 || c == 74074520320 || !(g < 2))
>+ {
>+ k = c;
>+ l = g;
>+ c = ~((k && c) + ~l);
>+ f = ~(f * (c ^ k) | l);
>+ if (c > k)
>+ __builtin_printf ("%d\n", f);
>+ }
>+ short m = -f;
>+ unsigned long long n = c;
>+ c = m * f | n % c;
>+ if (n)
>+ __builtin_printf ("%d\n", f);
>+ while (f < -31807)
>+ ;
>+ c = ~(n | c) | f;
>+ if (n < c)
>+ __builtin_printf ("%lld\n", (long long) f);
>+ for (; d;)
>+ for (; e;)
>+ for (;;)
>+ ;
>+ c = h;
>+ c = l % c;
>+}
>
> Jakub
