public inbox for
 help / color / mirror / Atom feed
* [COMMITTED] Check if varying may also be non-negative.
@ 2022-10-26 13:49 Andrew MacLeod
  0 siblings, 0 replies; only message in thread
From: Andrew MacLeod @ 2022-10-26 13:49 UTC (permalink / raw)
  To: gcc-patches; +Cc: hernandez, aldy

[-- Attachment #1: Type: text/plain, Size: 399 bytes --]

When strict enums are in use, we don't always get ranges reduced 
sufficiently thru casts and such.  Ranger vrp has been missing the odd 
case because I didn't notice that gimple_stmt_nonnegative_warnv_p() use 
to be called on all integral results that were varying, not just calls 
like it was doing. this corrects that.

Bootstrapped on x86_64-pc-linux-gnu with no regressions.  Pushed.


[-- Attachment #2: 0001 --]
[-- Type: text/plain, Size: 1220 bytes --]

commit a87819b8f1b890d36a3f05bd9de80be20e9525dd
Author: Andrew MacLeod <>
Date:   Tue Oct 25 15:16:47 2022 -0400

    Check if varying may also be non-negative.
    When using strict enums, we can sometimes turn varying into a better
            * (fold_using_range::fold_stmt): Check if
            stmt is non-negative and adjust the range.

diff --git a/gcc/ b/gcc/
index f91923782dc..a899d8260b3 100644
--- a/gcc/
+++ b/gcc/
@@ -494,6 +494,14 @@ fold_using_range::fold_stmt (vrange &r, gimple *s, fur_source &src, tree name)
   else if (is_a<gassign *> (s) && gimple_assign_rhs_code (s) == COND_EXPR)
     res = range_of_cond_expr (r, as_a<gassign *> (s), src);
+  // If the result is varying, check for basic nonnegativeness.
+  // Specifically this helps for now with strict enum in cases like
+  // g++.dg/warn/pr33738.C.
+  bool so_p;
+  if (res && r.varying_p () && INTEGRAL_TYPE_P (r.type ())
+      && gimple_stmt_nonnegative_warnv_p (s, &so_p))
+    r.set_nonnegative (r.type ());
   if (!res)
       // If no name specified or range is unsupported, bail.

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2022-10-26 13:49 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-10-26 13:49 [COMMITTED] Check if varying may also be non-negative Andrew MacLeod

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).