[PATCH] gimple-fold, v2: Fix fold_truth_andor_for_ifcombine [PR120074]

[Jakub Jelinek]

On Mon, May 05, 2025 at 09:02:15AM +0200, Jakub Jelinek wrote:
> The other option would be
> +       if (ll_bitsize != lr_bitsize)
> +         return 0;
>         if (!lr_and_mask.get_precision ())
>           lr_and_mask = sign;
>         else
>           lr_and_mask &= sign;
> and similarly in the other hunk.

Here is the second option in patch form, so far briefly tested on the
testcase.

2025-05-05  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/120074
        * gimple-fold.cc (fold_truth_andor_for_ifcombine): For
        lsignbit && l_xor case, punt if ll_bitsize != lr_bitsize.  Similarly
        for rsignbit && r_xor case, punt if rl_bitsize != rr_bitsize.
        Formatting fix.

        * gcc.dg/pr120074.c: New test.

--- gcc/gimple-fold.cc.jj       2025-04-21 17:04:48.000000000 +0200
+++ gcc/gimple-fold.cc  2025-05-05 09:36:14.208753999 +0200
@@ -8334,6 +8334,8 @@ fold_truth_andor_for_ifcombine (enum tre
        ll_and_mask &= sign;
       if (l_xor)
        {
+         if (ll_bitsize != lr_bitsize)
+           return 0;
          if (!lr_and_mask.get_precision ())
            lr_and_mask = sign;
          else
@@ -8355,6 +8357,8 @@ fold_truth_andor_for_ifcombine (enum tre
        rl_and_mask &= sign;
       if (r_xor)
        {
+         if (rl_bitsize != rr_bitsize)
+           return 0;
          if (!rr_and_mask.get_precision ())
            rr_and_mask = sign;
          else
@@ -8762,7 +8766,7 @@ fold_truth_andor_for_ifcombine (enum tre
       wide_int lr_mask, rr_mask;
       if (lr_and_mask.get_precision ())
        lr_mask = wi::lshift (wide_int::from (lr_and_mask, rnprec, UNSIGNED),
-                         xlr_bitpos);
+                             xlr_bitpos);
       else
        lr_mask = wi::shifted_mask (xlr_bitpos, lr_bitsize, false, rnprec);
       if (rr_and_mask.get_precision ())
--- gcc/testsuite/gcc.dg/pr120074.c.jj  2025-05-03 13:55:45.374319266 +0200
+++ gcc/testsuite/gcc.dg/pr120074.c     2025-05-03 13:54:53.264995823 +0200
@@ -0,0 +1,20 @@
+/* PR tree-optimization/120074 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fno-tree-copy-prop -fno-tree-forwprop -fno-tree-ccp" } */
+
+int foo (int);
+short a;
+int b;
+
+int
+bar (int d, int e)
+{
+  return d < 0 || d > __INT_MAX__ >> e;
+}
+
+int
+main ()
+{
+  int f = bar ((b ^ a) & 3, __SIZEOF_INT__ * __CHAR_BIT__ - 2);
+  foo (f);
+}


        Jakub