[Bug tree-optimization/95694] [9/10/11 Regression] ICE in trunc_int_for_mode, at explow.c:59 since r9-7156-g33579b59aaf02eb7

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95694

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org
   Target Milestone|---                         |9.4

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
We're expanding

 <ssa_name 0x7ffff6bc1e10
    type <integer_type 0x7ffff6cf03f0 sizes-gimplified public unsigned TI
        size <integer_cst 0x7ffff6bb7d20 constant 128>
        unit-size <integer_cst 0x7ffff6bb7d38 constant 16>
        align:128 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff6cf03f0 precision:65 min <integer_cst 0x7ffff6d0d018 0> max <integer_cst
0x7ffff6cf6100 0x1ffffffffffffffff>>
    visited
    def_stmt _5 = (<unnamed-unsigned:65>) _4;
    version:5>

and

#2  0x0000000000d9a5bf in reduce_to_bit_field_precision (exp=0x7ffff6d1d180, 
    target=0x0, type=<integer_type 0x7ffff6cf03f0>)
    at /space/rguenther/src/gcc/gcc/expr.c:11553
(gdb) p debug_rtx (exp)
(const_wide_int 0x1fffffffffffffffe)
$1 = void
(gdb) p debug_tree (type)
 <integer_type 0x7ffff6cf03f0 sizes-gimplified public unsigned TI
    size <integer_cst 0x7ffff6bb7d20 type <integer_type 0x7ffff6bd00a8
bitsizetype> constant 128>
    unit-size <integer_cst 0x7ffff6bb7d38 type <integer_type 0x7ffff6bd0000
sizetype> constant 16>
    align:128 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff6cf03f0 precision:65 min <integer_cst 0x7ffff6d0d018 0> max <integer_cst
0x7ffff6cf6100 0x1ffffffffffffffff>>
$2 = void

here a CONST_WIDE_INT does not have a mode.  Note somehow the earlier

  /* For constant values, reduce using build_int_cst_type. */
  poly_int64 const_exp;
  if (poly_int_rtx_p (exp, &const_exp))
    {
      tree t = build_int_cst_type (type, const_exp);
      return expand_expr (t, target, VOIDmode, EXPAND_NORMAL);
    }

does not trigger.  Ah, poly_int64 ...  but

diff --git a/gcc/expr.c b/gcc/expr.c
index ca6b1c1291e..7367e332a05 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -11541,11 +11541,10 @@ reduce_to_bit_field_precision (rtx exp, rtx target,
tree type)
   HOST_WIDE_INT prec = TYPE_PRECISION (type);
   if (target && GET_MODE (target) != GET_MODE (exp))
     target = 0;
-  /* For constant values, reduce using build_int_cst_type. */
-  poly_int64 const_exp;
-  if (poly_int_rtx_p (exp, &const_exp))
+  /* For constant values, reduce using build_poly_int_cst. */
+  if (poly_int_rtx_p (exp))
     {
-      tree t = build_int_cst_type (type, const_exp);
+      tree t = build_poly_int_cst (type, wi::to_poly_wide (exp));
       return expand_expr (t, target, VOIDmode, EXPAND_NORMAL);
     }
   else if (TYPE_UNSIGNED (type))

does not compile and insists on a mode - but the implementation for
poly_int64 does not need a mode.  And we shouldn't need one (and the
whole point of this path is we don't have one).

Richard?  Can you please take this?