On 02/14/2017 06:43 AM, Jakub Jelinek wrote:
On Tue, Feb 14, 2017 at 08:18:13AM +0100, Jakub Jelinek wrote:
On Mon, Feb 13, 2017 at 04:53:19PM -0700, Jeff Law wrote:
dirtype is one of the standard {un,}signed {char,short,int,long,long long}
types, all of them have 0 in their ranges.
For VR_RANGE we almost always set res.knownrange to true:
/* Set KNOWNRANGE if the argument is in a known subrange
of the directive's type (KNOWNRANGE may be reset below). */
res.knownrange
= (!tree_int_cst_equal (TYPE_MIN_VALUE (dirtype), argmin)
|| !tree_int_cst_equal (TYPE_MAX_VALUE (dirtype), argmax));
(the exception is in case that range clearly has to include zero),
and reset it only if adjust_range_for_overflow returned true, which means
it also set the range to TYPE_M{IN,AX}_VALUE (dirtype) and again
includes zero.
So IMNSHO likely_adjust in what you've committed is always true
when you use it and thus just a useless computation and something to make
the code harder to understand.
If KNOWNRANGE is false, then LIKELY_ADJUST will be true. But I don't see
how we can determine anything for LIKELY_ADJUST if KNOWNRANGE is true.
We can't, but that doesn't matter, we only use it if KNOWNRANGE is false.
The only user of LIKELY_ADJUST is:
if (res.knownrange)
res.range.likely = res.range.max;
else
{
// -- Here we know res.knownrage is false
res.range.likely = res.range.min;
if (likely_adjust && maybebase && base != 10)
// -- and here is the only user of likely_adjust
{
if (res.range.min == 1)
res.range.likely += base == 8 ? 1 : 2;
else if (res.range.min == 2
&& base == 16
&& (dir.width[0] == 2 || dir.prec[0] == 2))
++res.range.likely;
}
}
Duh. You're obviously right. Still reading the rest of the thread.
jeff
