[Bug rtl-optimization/64882] [5 Regression] ICE on valid code at -O3 with -g enabled in simplify_subreg, at simplify-rtx.c:5681

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64882

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ebotcazou at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
And the problem seems to be that the mode argument to address_no_seg_operand
predicate is completely ignored.

The big question is where to fix this.
I've tried changing ix86_legitimate_address_p, but that ICEs pretty much
everywhere, on the other side doing it just in address_no_seg_operand might be
sufficient for this exact testcase, but what about others? 
config/i386/predicates.md has tons of predicates that check "address_operand"
and do something on top of that.

--- gcc/recog.c.jj    2015-01-15 20:25:30.000000000 +0100
+++ gcc/recog.c    2015-01-31 11:33:28.546090770 +0100
@@ -1122,6 +1122,8 @@ general_operand (rtx op, machine_mode mo
 int
 address_operand (rtx op, machine_mode mode)
 {
+  if (GET_MODE (op) != mode && mode != VOIDmode && GET_MODE (op) != VOIDmode)
+    return 0;
   return memory_address_p (mode, op);
 }

seems to fix this testcase, can try to bootstrap/regtest that, but as it is a
generic change, there is a risk of breaking many other ports.

So, any thoughts on this?  Or should it be postreload's duty to verify that
modes match?