[gcc r10-11352] cse: Fix up CSE const_anchor handling [PR108193]

[gcc r10-11352] cse: Fix up CSE const_anchor handling [PR108193]

[Jakub Jelinek]

https://gcc.gnu.org/g:14cb8af5a6a1f09250a207359535399fedbbb4ff

commit r10-11352-g14cb8af5a6a1f09250a207359535399fedbbb4ff
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Dec 22 12:44:13 2022 +0100

    cse: Fix up CSE const_anchor handling [PR108193]
    
    The following testcase ICEs on aarch64, because insert_const_anchor
    inserts invalid CONST_INT into the CSE tables - 0x80000000 for SImode.
    The second hunk of the patch fixes that, the first one is to avoid
    triggering undefined behavior at compile time during compute_const_anchors
    computations - performing those additions and subtractions in
    HOST_WIDE_INT means it can overflow for certain constants.
    
    2022-12-22  Jakub Jelinek  <jakub@redhat.com>
    
            PR rtl-optimization/108193
            * cse.c (compute_const_anchors): Change n type to
            unsigned HOST_WIDE_INT, adjust comparison against it to avoid
            warnings.  Formatting fix.
            (insert_const_anchor): Use gen_int_mode instead of GEN_INT.
    
            * gfortran.dg/pr108193.f90: New test.
    
    (cherry picked from commit 0cb5d7cdbab8e5f8359764ef5f62d93c2bc88552)

Diff:
---
 gcc/cse.c                              | 10 +++++-----
 gcc/testsuite/gfortran.dg/pr108193.f90 | 24 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/gcc/cse.c b/gcc/cse.c
index f69a33a82e0..7253b7caf6c 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -1190,14 +1190,14 @@ compute_const_anchors (rtx cst,
 		       HOST_WIDE_INT *lower_base, HOST_WIDE_INT *lower_offs,
 		       HOST_WIDE_INT *upper_base, HOST_WIDE_INT *upper_offs)
 {
-  HOST_WIDE_INT n = INTVAL (cst);
+  unsigned HOST_WIDE_INT n = UINTVAL (cst);
 
   *lower_base = n & ~(targetm.const_anchor - 1);
-  if (*lower_base == n)
+  if ((unsigned HOST_WIDE_INT) *lower_base == n)
     return false;
 
-  *upper_base =
-    (n + (targetm.const_anchor - 1)) & ~(targetm.const_anchor - 1);
+  *upper_base = ((n + (targetm.const_anchor - 1))
+		 & ~(targetm.const_anchor - 1));
   *upper_offs = n - *upper_base;
   *lower_offs = n - *lower_base;
   return true;
@@ -1214,7 +1214,7 @@ insert_const_anchor (HOST_WIDE_INT anchor, rtx reg, HOST_WIDE_INT offs,
   rtx anchor_exp;
   rtx exp;
 
-  anchor_exp = GEN_INT (anchor);
+  anchor_exp = gen_int_mode (anchor, mode);
   hash = HASH (anchor_exp, mode);
   elt = lookup (anchor_exp, hash, mode);
   if (!elt)
diff --git a/gcc/testsuite/gfortran.dg/pr108193.f90 b/gcc/testsuite/gfortran.dg/pr108193.f90
new file mode 100644
index 00000000000..3a3655f1248
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr108193.f90
@@ -0,0 +1,24 @@
+! PR rtl-optimization/108193
+! { dg-do compile { target pthread } }
+! { dg-options "-O2 -fsplit-loops -ftree-parallelize-loops=2 -fno-tree-dominator-opts" }
+
+subroutine foo (n, r)
+  implicit none
+  integer :: i, j, n
+  real :: s, r(*)
+
+  s = 0.0
+
+  do j = 1, 2
+     do i = j, n
+        s = r(i)
+     end do
+  end do
+
+  do i = 1, n
+     do j = i, n
+        s = s + 1
+     end do
+     r(i) = s
+  end do
+end subroutine foo