[OE-core] [PATCH] gcc-9.2: fix bug #91102 'aarch64 ICE on Linux kernel with -Os'

[Khem Raj]

this is ok. Also please ask it to be backported to 9.3 on gcc bugzilla

On Mon, Feb 3, 2020 at 6:20 PM Taras Kondratiuk <takondra at cisco.com> wrote:
>
> Linux kernel compilation for aarch64 triggers ICE if
> CONFIG_CC_OPTIMIZE_FOR_SIZE=y.
>
> The rootcause is GCC bug #91102 'aarch64 ICE on Linux kernel with -Os'.
> Apply the fix to 9.2.
>
> Signed-off-by: Taras Kondratiuk <takondra at cisco.com>
> ---
>  meta/recipes-devtools/gcc/gcc-9.2.inc         |  1 +
>  ...02-aarch64-ICE-on-Linux-kernel-with-.patch | 95 +++++++++++++++++++
>  2 files changed, 96 insertions(+)
>  create mode 100644 meta/recipes-devtools/gcc/gcc-9.2/re-PR-target-91102-aarch64-ICE-on-Linux-kernel-with-.patch
>
> diff --git a/meta/recipes-devtools/gcc/gcc-9.2.inc b/meta/recipes-devtools/gcc/gcc-9.2.inc
> index 926df11c2782..2bae85afe3a3 100644
> --- a/meta/recipes-devtools/gcc/gcc-9.2.inc
> +++ b/meta/recipes-devtools/gcc/gcc-9.2.inc
> @@ -69,6 +69,7 @@ SRC_URI = "\
>            file://CVE-2019-15847_1.patch \
>            file://CVE-2019-15847_2.patch \
>            file://CVE-2019-15847_3.patch \
> +           file://re-PR-target-91102-aarch64-ICE-on-Linux-kernel-with-.patch \
>  "
>  S = "${TMPDIR}/work-shared/gcc-${PV}-${PR}/gcc-${PV}"
>  SRC_URI[md5sum] = "3818ad8600447f05349098232c2ddc78"
> diff --git a/meta/recipes-devtools/gcc/gcc-9.2/re-PR-target-91102-aarch64-ICE-on-Linux-kernel-with-.patch b/meta/recipes-devtools/gcc/gcc-9.2/re-PR-target-91102-aarch64-ICE-on-Linux-kernel-with-.patch
> new file mode 100644
> index 000000000000..c37e0bb9dd9b
> --- /dev/null
> +++ b/meta/recipes-devtools/gcc/gcc-9.2/re-PR-target-91102-aarch64-ICE-on-Linux-kernel-with-.patch
> @@ -0,0 +1,95 @@
> +From efb0ee06f5c0186c2d1442ecd4dbbd55dbd97b44 Mon Sep 17 00:00:00 2001
> +From: Vladimir Makarov <vmakarov at redhat.com>
> +Date: Wed, 10 Jul 2019 16:07:10 +0000
> +Subject: [PATCH] re PR target/91102 (aarch64 ICE on Linux kernel with -Os
> + starting with r270266)
> +
> +2019-07-10  Vladimir Makarov  <vmakarov at redhat.com>
> +
> +       PR target/91102
> +       * lra-constraints.c (process_alt_operands): Don't match user
> +       defined regs only if they are early clobbers.
> +
> +2019-07-10  Vladimir Makarov  <vmakarov at redhat.com>
> +
> +       PR target/91102
> +       * gcc.target/aarch64/pr91102.c: New test.
> +
> +From-SVN: r273357
> +Upstream-Status: Backport [https://github.com/gcc-mirror/gcc/commit/613caed2feb9cfc8158308670b59df3d031ec629]
> +[takondra: dropped conflicting ChangeLog changes]
> +Signed-off-by: Taras Kondratiuk <takondra at cisco.com>
> +---
> + gcc/lra-constraints.c                      | 17 ++++++++++----
> + gcc/testsuite/gcc.target/aarch64/pr91102.c | 26 ++++++++++++++++++++++
> + 2 files changed, 39 insertions(+), 4 deletions(-)
> + create mode 100644 gcc/testsuite/gcc.target/aarch64/pr91102.c
> +
> +diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
> +index cf33da8013e4..6382dbf852b6 100644
> +--- a/gcc/lra-constraints.c
> ++++ b/gcc/lra-constraints.c
> +@@ -2172,8 +2172,9 @@ process_alt_operands (int only_alternative)
> +                   else
> +                     {
> +                       /* Operands don't match.  If the operands are
> +-                         different user defined explicit hard registers,
> +-                         then we cannot make them match.  */
> ++                         different user defined explicit hard
> ++                         registers, then we cannot make them match
> ++                         when one is early clobber operand.  */
> +                       if ((REG_P (*curr_id->operand_loc[nop])
> +                            || SUBREG_P (*curr_id->operand_loc[nop]))
> +                           && (REG_P (*curr_id->operand_loc[m])
> +@@ -2192,9 +2193,17 @@ process_alt_operands (int only_alternative)
> +                               && REG_P (m_reg)
> +                               && HARD_REGISTER_P (m_reg)
> +                               && REG_USERVAR_P (m_reg))
> +-                            break;
> ++                            {
> ++                              int i;
> ++
> ++                              for (i = 0; i < early_clobbered_regs_num; i++)
> ++                                if (m == early_clobbered_nops[i])
> ++                                  break;
> ++                              if (i < early_clobbered_regs_num
> ++                                  || early_clobber_p)
> ++                                break;
> ++                            }
> +                         }
> +-
> +                       /* Both operands must allow a reload register,
> +                          otherwise we cannot make them match.  */
> +                       if (curr_alt[m] == NO_REGS)
> +diff --git a/gcc/testsuite/gcc.target/aarch64/pr91102.c b/gcc/testsuite/gcc.target/aarch64/pr91102.c
> +new file mode 100644
> +index 000000000000..70b99045a48e
> +--- /dev/null
> ++++ b/gcc/testsuite/gcc.target/aarch64/pr91102.c
> +@@ -0,0 +1,26 @@
> ++/* PR target/91102 */
> ++/* { dg-do compile } */
> ++/* { dg-options "-O2" } */
> ++
> ++int
> ++foo (long d, long l)
> ++{
> ++  register long e asm ("x1") = d;
> ++  register long f asm("x2") = l;
> ++  asm ("" : : "r" (e), "r" (f));
> ++  return 3;
> ++}
> ++
> ++struct T { int i; int j; };
> ++union S { long h; struct T t; };
> ++
> ++void
> ++bar (union S b)
> ++{
> ++  while (1)
> ++    {
> ++      union S c = b;
> ++      c.t.j++;
> ++      b.h = foo (b.h, c.h);
> ++    }
> ++}
> --
> 2.18.1
>