public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
* [PATCH] Fix up foperator_abs::op1_range [PR107569]
@ 2022-11-09 10:55 Jakub Jelinek
  2022-11-09 11:32 ` Aldy Hernandez
  0 siblings, 1 reply; 2+ messages in thread
From: Jakub Jelinek @ 2022-11-09 10:55 UTC (permalink / raw)
  To: Aldy Hernandez; +Cc: gcc-patches

Hi!

foperator_abs::op1_range works except for the NaN handling,
from:
[frange] double [-Inf, 1.79769313486231570814527423731704356798070567525844996599e+308 (0x0.fffffffffffff8p+1024)]
lhs it computes r
[frange] double [-1.79769313486231570814527423731704356798070567525844996599e+308 (-0x0.fffffffffffff8p+1024), 1.79769313486231570814527423731704356798070567525844996599e+308 (0x0.fffffffffffff8p+1024)] +-NAN
which is correct except for the +-NAN part.
For r before the final step it makes sure to add -NAN if there is +NAN
in the lhs range, but the final r.union_ makes it unconditional +-NAN,
because the frange ctor sets +-NAN.
So, I think we need to clear it (or have some set variant which
says not to set NAN).

This patch fixes that, but isn't enough to fix the PR, something in
the assumptions handling is still broken (and the PR has other parts).

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2022-11-09  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/107569
	* range-op-float.cc (foperator_abs::op1_range): Clear NaNs
	from the negatives frange before unioning it into r.

--- gcc/range-op-float.cc.jj	2022-11-06 11:56:27.138137781 +0100
+++ gcc/range-op-float.cc	2022-11-08 18:13:18.026974667 +0100
@@ -1280,9 +1280,10 @@ foperator_abs::op1_range (frange &r, tre
     return true;
   // Then add the negative of each pair:
   // ABS(op1) = [5,20] would yield op1 => [-20,-5][5,20].
-  r.union_ (frange (type,
-		    real_value_negate (&positives.upper_bound ()),
-		    real_value_negate (&positives.lower_bound ())));
+  frange negatives (type, real_value_negate (&positives.upper_bound ()),
+		    real_value_negate (&positives.lower_bound ()));
+  negatives.clear_nan ();
+  r.union_ (negatives);
   return true;
 }
 

	Jakub


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2022-11-09 11:32 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-09 10:55 [PATCH] Fix up foperator_abs::op1_range [PR107569] Jakub Jelinek
2022-11-09 11:32 ` Aldy Hernandez

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).