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[Bug rtl-optimization/37544] [4.2/4.3/4.4 Regression] Conversion double -> unsigned long long -> unsigned -> double gives wrong results
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 17 Sep 2008 10:39:31 -0000
- Subject: [Bug rtl-optimization/37544] [4.2/4.3/4.4 Regression] Conversion double -> unsigned long long -> unsigned -> double gives wrong results
- References: <bug-37544-16622@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #8 from ubizjak at gmail dot com 2008-09-17 10:39 -------
The problem is in regrename.c, function maybe_mode_change. We enter the
function with:
orig_mode = DImode
copy_mode = SImode
new_mode = DImode
At the beginning of maybe_mode_change() we have:
if (orig_mode == new_mode)
return gen_rtx_raw_REG (new_mode, regno);
we simply discard the change to a narrower mode.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37544