Hi!
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.
Bootstrapped/regtested on aarch64-linux (which does have nonzero
target.const_anchor) and x86_64-linux and i686-linux (which have it
zero). Ok for trunk?
2022-12-22 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/108193
* cse.cc (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.
--- gcc/cse.cc.jj 2022-06-28 13:03:30.699692752 +0200
+++ gcc/cse.cc 2022-12-21 12:58:24.277945065 +0100
@@ -1169,14 +1169,14 @@ 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 = INTVAL (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;
@@ -1193,7 +1193,7 @@ insert_const_anchor (HOST_WIDE_INT ancho
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)
--- gcc/testsuite/gfortran.dg/pr108193.f90.jj 2022-12-21 13:02:21.925513332
+0100
+++ gcc/testsuite/gfortran.dg/pr108193.f90 2022-12-21 13:01:38.595139040
+0100
@@ -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
Jakub
