commit:     45d4820445bee14f31c0f6381504c67ebc5d0c52
Author:     Sam James <sam <AT> gentoo <DOT> org>
AuthorDate: Sun Jul 27 01:00:15 2025 +0000
Commit:     Sam James <sam <AT> gentoo <DOT> org>
CommitDate: Sun Jul 27 01:01:24 2025 +0000
URL:        https://gitweb.gentoo.org/proj/gcc-patches.git/commit/?id=45d48204

15.1.0: backport SRA fix, cut patchset 4

Note that the fix for the related https://gcc.gnu.org/PR117423 is already
on the 15 branch.

Bug: https://bugs.gentoo.org/941225
Bug: https://gcc.gnu.org/PR119085
Signed-off-by: Sam James <sam <AT> gentoo.org>

 15.1.0/gentoo/86_all_PR119085.patch | 98 +++++++++++++++++++++++++++++++++++++
 15.1.0/gentoo/README.history        |  4 ++
 2 files changed, 102 insertions(+)

diff --git a/15.1.0/gentoo/86_all_PR119085.patch 
b/15.1.0/gentoo/86_all_PR119085.patch
new file mode 100644
index 0000000..cf145a6
--- /dev/null
+++ b/15.1.0/gentoo/86_all_PR119085.patch
@@ -0,0 +1,98 @@
+https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=171fcc80ede596442712e559c4fc787aa4636694
+
+From 171fcc80ede596442712e559c4fc787aa4636694 Mon Sep 17 00:00:00 2001
+From: Martin Jambor <[email protected]>
+Date: Wed, 23 Jul 2025 11:22:33 +0200
+Subject: [PATCH] tree-sra: Avoid total SRA if there are incompat. aggregate
+ accesses  (PR119085)
+
+We currently use the types encountered in the function body and not in
+type declaration to perform total scalarization.  Bug PR 119085
+uncovered that we miss a check that when the same data is accessed
+with aggregate types that those are actually compatible.  Without it,
+we can base total scalarization on a type that does not "cover" all
+live data in a different part of the function.  This patch adds the
+check.
+
+gcc/ChangeLog:
+
+2025-07-21  Martin Jambor  <[email protected]>
+
+       PR tree-optimization/119085
+       * tree-sra.cc (sort_and_splice_var_accesses): Prevent total
+       scalarization if two incompatible aggregates access the same place.
+
+gcc/testsuite/ChangeLog:
+
+2025-07-21  Martin Jambor  <[email protected]>
+
+       PR tree-optimization/119085
+       * gcc.dg/tree-ssa/pr119085.c: New test.
+---
+ gcc/testsuite/gcc.dg/tree-ssa/pr119085.c | 37 ++++++++++++++++++++++++
+ gcc/tree-sra.cc                          |  6 ++++
+ 2 files changed, 43 insertions(+)
+ create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr119085.c
+
+diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr119085.c 
b/gcc/testsuite/gcc.dg/tree-ssa/pr119085.c
+new file mode 100644
+index 000000000000..e9811ce12b58
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/tree-ssa/pr119085.c
+@@ -0,0 +1,37 @@
++/* { dg-do run } */
++/* { dg-options "-O1" } */
++
++struct with_hole {
++  int x;
++  long y;
++};
++struct without_hole {
++  int x;
++  int y;
++};
++union u {
++  struct with_hole with_hole;
++  struct without_hole without_hole;
++};
++
++void __attribute__((noinline))
++test (union u *up, union u u)
++{
++  union u u2;
++  volatile int f = 0;
++  u2 = u;
++  if (f)
++    u2.with_hole = u.with_hole;
++  *up = u2;
++}
++
++int main(void)
++{
++  union u u;
++  union u u2;
++  u2.without_hole.y = -1;
++  test (&u, u2);
++  if (u.without_hole.y != -1)
++    __builtin_abort ();
++  return 0;
++}
+diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
+index 240af676ea33..032f27704847 100644
+--- a/gcc/tree-sra.cc
++++ b/gcc/tree-sra.cc
+@@ -2504,6 +2504,12 @@ sort_and_splice_var_accesses (tree var)
+               }
+             unscalarizable_region = true;
+           }
++        /* If there the same place is accessed with two incompatible
++           aggregate types, trying to base total scalarization on either of
++           them can be wrong.  */
++        if (!first_scalar && !types_compatible_p (access->type, ac2->type))
++          bitmap_set_bit (cannot_scalarize_away_bitmap,
++                          DECL_UID (access->base));
+ 
+         if (grp_same_access_path
+             && (!ac2->grp_same_access_path
+-- 
+2.43.7

diff --git a/15.1.0/gentoo/README.history b/15.1.0/gentoo/README.history
index d89a94a..2b37a49 100644
--- a/15.1.0/gentoo/README.history
+++ b/15.1.0/gentoo/README.history
@@ -1,3 +1,7 @@
+4      27 July 2025
+
+       + 86_all_PR119085.patch
+
 3      13 July 2025
 
        - 86_all_PR120358-qt-pta.patch

Reply via email to