On 02/14/2017 12:18 AM, 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; } }Even if you don't trust this, with the ranges in argmin/argmax, it is IMHO undesirable to set it differently at the different code paths, if you want to check whether the final range includes zero and at least one another value, just do - if (likely_adjust && maybebase && base != 10) + if ((tree_int_cst_sgn (argmin) < 0 || tree_int_cst_sgn (argmax) > 0) && maybebase && base != 10) Though, it is useless both for the above reason and for the reason that you actually do something only:I'm not convinced it's useless, but it does seem advisable to bring test down to where it's actually used and to bse it strictly on argmin/argmax. Can you test a patch which does that?That would then be (the only difference compared to the previous patch is the last hunk) following. I can surely test that, I'm still convinced it would work equally if that (tree_int_cst_sgn (argmin) < 0 || tree_int_cst_sgn (argmax) > 0) is just gcc_checking_assert. 2017-02-14 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/79327 * gimple-ssa-sprintf.c (format_integer): Remove likely_adjust variable, its initialization and use. --- gcc/gimple-ssa-sprintf.c.jj 2017-02-04 08:43:12.000000000 +0100 +++ gcc/gimple-ssa-sprintf.c 2017-02-04 08:45:33.173709580 +0100 @@ -1232,10 +1232,6 @@ format_integer (const directive &dir, tr of the format string by returning [-1, -1]. */ return fmtresult (); - /* True if the LIKELY counter should be adjusted upward from the MIN - counter to account for arguments with unknown values. */ - bool likely_adjust = false; - fmtresult res; /* Using either the range the non-constant argument is in, or its @@ -1265,14 +1261,6 @@ format_integer (const directive &dir, tr res.argmin = argmin; res.argmax = argmax; - - /* Set the adjustment for an argument whose range includes - zero since that doesn't include the octal or hexadecimal - base prefix. */ - wide_int wzero = wi::zero (wi::get_precision (min)); - if (wi::le_p (min, wzero, SIGNED) - && !wi::neg_p (max)) - likely_adjust = true; } else if (range_type == VR_ANTI_RANGE) { @@ -1307,11 +1295,6 @@ format_integer (const directive &dir, tr if (!argmin) { - /* Set the adjustment for an argument whose range includes - zero since that doesn't include the octal or hexadecimal - base prefix. */ - likely_adjust = true; - if (TREE_CODE (argtype) == POINTER_TYPE) { argmin = build_int_cst (pointer_sized_int_node, 0); @@ -1371,7 +1354,8 @@ format_integer (const directive &dir, tr else { res.range.likely = res.range.min; - if (likely_adjust && maybebase && base != 10) + if (maybebase && base != 10 + && (tree_int_cst_sgn (argmin) < 0 || tree_int_cst_sgn (argmax) > 0)) { if (res.range.min == 1) res.range.likely += base == 8 ? 1 : 2;
You've removed all the comments that explain what's going on. If you must make the change (I see no justification for it now) please at least document it. Martin
