[Bug rtl-optimization/68636] unnecessary unaligned load on mips o32

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68636

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fix:

Index: gcc/builtins.c
===================================================================
--- gcc/builtins.c      (revision 231058)
+++ gcc/builtins.c      (working copy)
@@ -497,6 +497,10 @@ get_pointer_alignment_1 (tree exp, unsig
        {
          *bitposp = ptr_misalign * BITS_PER_UNIT;
          *alignp = ptr_align * BITS_PER_UNIT;
+         /* Make sure to return a sensible alignment when the multiplication
+            by BITS_PER_UNIT overflowed.  */
+         if (*alignp == 0)
+           *alignp = 1u << (HOST_BITS_PER_INT - 1);
          /* We cannot really tell whether this result is an approximation.  */
          return true;
        }