[meta-arm] [PATCH] arm-toolchain: Fix potential runtime crash

["Jon Mason" <jdmason@kudzu.us>]

Unless you have a problem with the patch below, I'm inclined to pull
it in ASAP.  However, given that the Arm GCC 9.x has been EoL'ed in
favor of the 10.x code, should we just drop support for it?

Thanks,
Jon

----- Forwarded message from Jon Mason <jon.mason@arm.com> -----

Date: Thu, 11 Feb 2021 11:36:47 -0500
From: Jon Mason <jon.mason@arm.com>
To: meta-arm@lists.yoctoproject.org
Subject: [meta-arm] [PATCH] arm-toolchain: Fix potential runtime crash

GCCv9 tree vectorization code is faulty and can cause random crashes at
runtime (when using -O3).  Add the backported patch to address this
issue.

Change-Id: If7bb0ba0720bab42e7d34f3679d988934f657392
Signed-off-by: Jon Mason <jon.mason@arm.com>
---
 .../recipes-devtools/gcc/gcc-arm-9.2.inc      |   1 +
 ...-PR-tree-optimization-97236-fix-bad-.patch | 119 ++++++++++++++++++
 2 files changed, 120 insertions(+)
 create mode 100644 meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2/0001-Backport-fix-for-PR-tree-optimization-97236-fix-bad-.patch

diff --git a/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2.inc b/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2.inc
index 08ad796..6378ecf 100644
--- a/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2.inc
+++ b/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2.inc
@@ -68,6 +68,7 @@ SRC_URI = "\
            file://0035-Fix-for-testsuite-failure.patch \
            file://0036-Re-introduce-spe-commandline-options.patch \
            file://0037-Fix-up-libsanitizer-build-with-master-glibc.patch \
+           file://0001-Backport-fix-for-PR-tree-optimization-97236-fix-bad-.patch \
 "
 SRC_URI[md5sum] = "9c570fc4286825b4e6f67b3d34aade23"
 
diff --git a/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2/0001-Backport-fix-for-PR-tree-optimization-97236-fix-bad-.patch b/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2/0001-Backport-fix-for-PR-tree-optimization-97236-fix-bad-.patch
new file mode 100644
index 0000000..dc1039d
--- /dev/null
+++ b/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-9.2/0001-Backport-fix-for-PR-tree-optimization-97236-fix-bad-.patch
@@ -0,0 +1,119 @@
+Upstream-Status: Backport [https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=97b668f9a8c6ec565c278a60e7d1492a6932e409]
+Signed-off-by: Jon Mason <jon.mason@arm.com>
+
+From 97b668f9a8c6ec565c278a60e7d1492a6932e409 Mon Sep 17 00:00:00 2001
+From: Matthias Klose <doko@ubuntu.com>
+Date: Tue, 6 Oct 2020 13:41:37 +0200
+Subject: [PATCH] Backport fix for PR/tree-optimization/97236 - fix bad use of
+ VMAT_CONTIGUOUS
+
+This avoids using VMAT_CONTIGUOUS with single-element interleaving
+when using V1mode vectors.  Instead keep VMAT_ELEMENTWISE but
+continue to avoid load-lanes and gathers.
+
+2020-10-01  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/97236
+	* tree-vect-stmts.c (get_group_load_store_type): Keep
+	VMAT_ELEMENTWISE for single-element vectors.
+
+	* gcc.dg/vect/pr97236.c: New testcase.
+
+(cherry picked from commit 1ab88985631dd2c5a5e3b5c0dce47cf8b6ed2f82)
+---
+ gcc/testsuite/gcc.dg/vect/pr97236.c | 43 +++++++++++++++++++++++++++++
+ gcc/tree-vect-stmts.c               | 20 ++++++--------
+ 2 files changed, 52 insertions(+), 11 deletions(-)
+ create mode 100644 gcc/testsuite/gcc.dg/vect/pr97236.c
+
+diff --git a/gcc/testsuite/gcc.dg/vect/pr97236.c b/gcc/testsuite/gcc.dg/vect/pr97236.c
+new file mode 100644
+index 000000000000..9d3dc20d953d
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/vect/pr97236.c
+@@ -0,0 +1,43 @@
++typedef unsigned char __uint8_t;
++typedef __uint8_t uint8_t;
++typedef struct plane_t {
++  uint8_t *p_pixels;
++  int i_lines;
++  int i_pitch;
++} plane_t;
++
++typedef struct {
++  plane_t p[5];
++} picture_t;
++
++#define N 4
++
++void __attribute__((noipa))
++picture_Clone(picture_t *picture, picture_t *res)
++{
++  for (int i = 0; i < N; i++) {
++    res->p[i].p_pixels = picture->p[i].p_pixels;
++    res->p[i].i_lines = picture->p[i].i_lines;
++    res->p[i].i_pitch = picture->p[i].i_pitch;
++  }
++}
++
++int
++main()
++{
++  picture_t aaa, bbb;
++  uint8_t pixels[10] = {1, 1, 1, 1, 1, 1, 1, 1};
++
++  for (unsigned i = 0; i < N; i++)
++    aaa.p[i].p_pixels = pixels;
++
++  picture_Clone (&aaa, &bbb);
++
++  uint8_t c = 0;
++  for (unsigned i = 0; i < N; i++)
++    c += bbb.p[i].p_pixels[0];
++
++  if (c != N)
++    __builtin_abort ();
++  return 0;
++}
+diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
+index 507f81b0a0e8..ffbba3441de2 100644
+--- a/gcc/tree-vect-stmts.c
++++ b/gcc/tree-vect-stmts.c
+@@ -2355,25 +2355,23 @@ get_group_load_store_type (stmt_vec_info stmt_info, tree vectype, bool slp,
+ 	  /* First cope with the degenerate case of a single-element
+ 	     vector.  */
+ 	  if (known_eq (TYPE_VECTOR_SUBPARTS (vectype), 1U))
+-	    *memory_access_type = VMAT_CONTIGUOUS;
++	    ;
+ 
+ 	  /* Otherwise try using LOAD/STORE_LANES.  */
+-	  if (*memory_access_type == VMAT_ELEMENTWISE
+-	      && (vls_type == VLS_LOAD
+-		  ? vect_load_lanes_supported (vectype, group_size, masked_p)
+-		  : vect_store_lanes_supported (vectype, group_size,
+-						masked_p)))
++	  else if (vls_type == VLS_LOAD
++		   ? vect_load_lanes_supported (vectype, group_size, masked_p)
++		   : vect_store_lanes_supported (vectype, group_size,
++						 masked_p))
+ 	    {
+ 	      *memory_access_type = VMAT_LOAD_STORE_LANES;
+ 	      overrun_p = would_overrun_p;
+ 	    }
+ 
+ 	  /* If that fails, try using permuting loads.  */
+-	  if (*memory_access_type == VMAT_ELEMENTWISE
+-	      && (vls_type == VLS_LOAD
+-		  ? vect_grouped_load_supported (vectype, single_element_p,
+-						 group_size)
+-		  : vect_grouped_store_supported (vectype, group_size)))
++	  else if (vls_type == VLS_LOAD
++		   ? vect_grouped_load_supported (vectype, single_element_p,
++						  group_size)
++		   : vect_grouped_store_supported (vectype, group_size))
+ 	    {
+ 	      *memory_access_type = VMAT_CONTIGUOUS_PERMUTE;
+ 	      overrun_p = would_overrun_p;
+-- 
+2.20.1
+
-- 
2.17.1







----- End forwarded message -----