https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89573
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jsm28 at gcc dot gnu.org
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The FE correctly builds
<<< Unknown tree: excess_precision_expr
(long double) __builtin_log (p) * (long double) inv_log_of_base >>>
but then convert_for_assignment seems to elide via convert_to_real_1:
/* Convert (outertype)((innertype0)a+(innertype1)b)
into ((newtype)a+(newtype)b) where newtype
is the widest mode from all of these. */
304 case PLUS_EXPR:
305 case MINUS_EXPR:
306 case MULT_EXPR:
307 case RDIV_EXPR:
308 {
309 tree arg0 = strip_float_extensions (TREE_OPERAND (expr,
0));
310 tree arg1 = strip_float_extensions (TREE_OPERAND (expr,
1));
where strip_float_extensions makes the comment not true (because we ignore
the casts to long double).
Maybe the code in convert_and_check
1627 if (TREE_CODE (expr) == EXCESS_PRECISION_EXPR)
1628 {
1629 tree orig_type = TREE_TYPE (expr);
1630 expr = TREE_OPERAND (expr, 0);
1631 expr_for_warning = convert (orig_type, expr);
1632 if (orig_type == type)
1633 return expr_for_warning;
shouldn't use convert here but convert_to_real_1 with fold_p = false?
But then other code may simply elide the conversions (can we really
ignore the extra rounding performed by the outer truncating conversion, ever?)
