Re: [google/4.6]Backport r184061 from upstream 4.6 (issue5712053)

[Jing Yu <jingyu at google dot com>]

The patch will be auto-merged into google/gcc-4_6 in near future.
I will cherry-pick it into google/gcc-4_6_2-mobile.

On Thu, Mar 1, 2012 at 10:50 AM, Jing Yu <jingyu@google.com> wrote:
> Backport r184061 from gcc-4_6 branch to fix an invalid
> constant simplification (PR52060).
>
> bootstrap and crosstool tests pass.
>
> OK for google/gcc-4_6 and google/gcc-4_6_2-mobile?
>
>
> 2012-03-01 ?Jing Yu ?<jingyu@google.com>
> ? ? ? ?Backport r184061 from gcc-4_6-branch to fix PR52060.
>
> ? ? ? ?2012-02-07 ?Jakub Jelinek ?<jakub@redhat.com>
> ? ? ? ?PR rtl-optimization/52060
> ? ? ? ?* gcc.dg/torture/pr52060.c: New test.
>
> 2012-03-01 ? Jing Yu ?<jingyu@google.com>
> ? ? ? ?Backport r184061 from gcc-4_6-branch to fix PR52060.
>
> ? ? ? ?2012-02-07 ?Jakub Jelinek ?<jakub@redhat.com>
> ? ? ? ?PR rtl-optimization/52060
> ? ? ? ?* combine.c (try_combine): Add i0src_copy and i0src_copy2 variables,
> ? ? ? ?copy i1src to i1src_copy whenever added_sets_2 && i1_feeds_i2_n
> ? ? ? ?already before i1dest -> i1src substitution in newpat, copy i0src
> ? ? ? ?to i0src_copy and/or i0src_copy2 when needed.
>
>
> Index: testsuite/ChangeLog.google-4_6
> ===================================================================
> --- testsuite/ChangeLog.google-4_6 ? ? ?(revision 184667)
> +++ testsuite/ChangeLog.google-4_6 ? ? ?(working copy)
> @@ -1,3 +1,10 @@
> +2012-03-01 ?Jing Yu ?<jingyu@google.com>
> + ? ? ? Backport r184061 from gcc-4_6-branch to fix PR52060.
> +
> + ? ? ? 2012-02-07 ?Jakub Jelinek ?<jakub@redhat.com>
> + ? ? ? PR rtl-optimization/52060
> + ? ? ? * gcc.dg/torture/pr52060.c: New test.
> +
> ?2012-02-19 ?Jeffrey Yasskin <jyasskin@google.com>
> ? ? ? ? Backport r183223 from gcc-4_6-branch to fix a segfault in C++11
> ? ? ? ?mode.
> Index: testsuite/gcc.dg/torture/pr52060.c
> ===================================================================
> --- testsuite/gcc.dg/torture/pr52060.c ?(revision 0)
> +++ testsuite/gcc.dg/torture/pr52060.c ?(revision 0)
> @@ -0,0 +1,57 @@
> +/* PR rtl-optimization/52060 */
> +/* { dg-do run { target int32plus } } */
> +
> +extern void abort (void);
> +union U { float f; unsigned int i; };
> +
> +static inline __attribute__((always_inline)) unsigned int
> +foo (float x)
> +{
> + ?union U u;
> + ?unsigned int a, b, c;
> + ?int d;
> + ?int e;
> + ?u.f = x;
> + ?d = ((unsigned) u.i >> 23) & 0xFF;
> + ?c = d < 126 ? 0 : ~0;
> + ?e = 127 + 30 - d;
> + ?a = (u.i << 8) | 0x80000000U;
> + ?b = a & ((1 << e) - 1);
> + ?a = a >> e;
> + ?c &= (b | (a & 2)) ? ~0 : ~1;
> + ?a = ((a + 1U) >> 1) & c;
> + ?return a;
> +}
> +
> +__attribute__((noinline)) unsigned int
> +bar (float x)
> +{
> + ?unsigned int a, b, c;
> + ?static const unsigned int d[128] =
> + ?{
> + ? ?0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + ? ?0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + ? ?0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + ? ?0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + ? ?1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + ? ?1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + ? ?2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
> + ? ?3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 6, 7
> + ?};
> + ?a = foo (1048575.0f * x);
> + ?c = d[a >> 13];
> + ?b = (c << 13) | ((a >> (7 - c)) & 0x1fff);
> + ?return b;
> +}
> +
> +int
> +main ()
> +{
> + ?union U u;
> + ?u.f = 1048575.0f;
> + ?if (sizeof (u.i) == sizeof (u.f)
> + ? ? ?&& u.i == 0x497ffff0U
> + ? ? ?&& bar (1.0f) != 65535)
> + ? ?abort ();
> + ?return 0;
> +}
> Index: ChangeLog.google-4_6
> ===================================================================
> --- ChangeLog.google-4_6 ? ? ? ?(revision 184667)
> +++ ChangeLog.google-4_6 ? ? ? ?(working copy)
> @@ -1,3 +1,13 @@
> +2012-03-01 ? Jing Yu ?<jingyu@google.com>
> + ? ? ? Backport r184061 from gcc-4_6-branch to fix PR52060.
> +
> + ? ? ? 2012-02-07 ?Jakub Jelinek ?<jakub@redhat.com>
> + ? ? ? PR rtl-optimization/52060
> + ? ? ? * combine.c (try_combine): Add i0src_copy and i0src_copy2 variables,
> + ? ? ? copy i1src to i1src_copy whenever added_sets_2 && i1_feeds_i2_n
> + ? ? ? already before i1dest -> i1src substitution in newpat, copy i0src
> + ? ? ? to i0src_copy and/or i0src_copy2 when needed.
> +
> ?2012-02-21 ? Jing Yu ?<jingyu@google.com>
>
> ? ? ? ?Google Ref 47894
> Index: combine.c
> ===================================================================
> --- combine.c ? (revision 184667)
> +++ combine.c ? (working copy)
> @@ -2551,8 +2551,8 @@
> ? rtx i3dest_killed = 0;
> ? /* SET_DEST and SET_SRC of I2, I1 and I0. ?*/
> ? rtx i2dest = 0, i2src = 0, i1dest = 0, i1src = 0, i0dest = 0, i0src = 0;
> - ?/* Copy of SET_SRC of I1, if needed. ?*/
> - ?rtx i1src_copy = 0;
> + ?/* Copy of SET_SRC of I1 and I0, if needed. ?*/
> + ?rtx i1src_copy = 0, i0src_copy = 0, i0src_copy2 = 0;
> ? /* Set if I2DEST was reused as a scratch register. ?*/
> ? bool i2scratch = false;
> ? /* The PATTERNs of I0, I1, and I2, or a copy of them in certain cases. ?*/
> @@ -3164,6 +3164,11 @@
> ? ? ? n_occurrences = 0;
> ? ? ? subst_low_luid = DF_INSN_LUID (i1);
>
> + ? ? ?/* If the following substitution will modify I1SRC, make a copy of it
> + ? ? ? ?for the case where it is substituted for I1DEST in I2PAT later. ?*/
> + ? ? ?if (added_sets_2 && i1_feeds_i2_n)
> + ? ? ? i1src_copy = copy_rtx (i1src);
> +
> ? ? ? /* If I0 feeds into I1 and I0DEST is in I0SRC, we need to make a unique
> ? ? ? ? copy of I1SRC each time we substitute it, in order to avoid creating
> ? ? ? ? self-referential RTL when we will be substituting I0SRC for I0DEST
> @@ -3191,10 +3196,14 @@
> ? ? ? ? ?return 0;
> ? ? ? ?}
>
> - ? ? ?/* If the following substitution will modify I1SRC, make a copy of it
> - ? ? ? ?for the case where it is substituted for I1DEST in I2PAT later. ?*/
> - ? ? ?if (i0_feeds_i1_n && added_sets_2 && i1_feeds_i2_n)
> - ? ? ? i1src_copy = copy_rtx (i1src);
> + ? ? ?/* If the following substitution will modify I0SRC, make a copy of it
> + ? ? ? ?for the case where it is substituted for I0DEST in I1PAT later. ?*/
> + ? ? ?if (added_sets_1 && i0_feeds_i1_n)
> + ? ? ? i0src_copy = copy_rtx (i0src);
> + ? ? ?/* And a copy for I0DEST in I2PAT substitution. ?*/
> + ? ? ?if (added_sets_2 && ((i0_feeds_i1_n && i1_feeds_i2_n)
> + ? ? ? ? ? ? ? ? ? ? ? ? ?|| (i0_feeds_i2_n)))
> + ? ? ? i0src_copy2 = copy_rtx (i0src);
>
> ? ? ? n_occurrences = 0;
> ? ? ? subst_low_luid = DF_INSN_LUID (i0);
> @@ -3260,7 +3269,7 @@
> ? ? ? ?{
> ? ? ? ? ?rtx t = i1pat;
> ? ? ? ? ?if (i0_feeds_i1_n)
> - ? ? ? ? ? t = subst (t, i0dest, i0src, 0, 0);
> + ? ? ? ? ? t = subst (t, i0dest, i0src_copy ? i0src_copy : i0src, 0, 0);
>
> ? ? ? ? ?XVECEXP (newpat, 0, --total_sets) = t;
> ? ? ? ?}
> @@ -3271,7 +3280,7 @@
> ? ? ? ? ? ?t = subst (t, i1dest, i1src_copy ? i1src_copy : i1src, 0,
> ? ? ? ? ? ? ? ? ? ? ? i0_feeds_i1_n && i0dest_in_i0src);
> ? ? ? ? ?if ((i0_feeds_i1_n && i1_feeds_i2_n) || i0_feeds_i2_n)
> - ? ? ? ? ? t = subst (t, i0dest, i0src, 0, 0);
> + ? ? ? ? ? t = subst (t, i0dest, i0src_copy2 ? i0src_copy2 : i0src, 0, 0);
>
> ? ? ? ? ?XVECEXP (newpat, 0, --total_sets) = t;
> ? ? ? ?}
>
> --
> This patch is available for review at http://codereview.appspot.com/5712053