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[Bug tree-optimization/37242] missed FRE opportunity
- From: "bonzini at gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 26 Aug 2008 12:02:05 -0000
- Subject: [Bug tree-optimization/37242] missed FRE opportunity
- References: <bug-37242-7849@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from bonzini at gnu dot org 2008-08-26 12:02 -------
This is missed because this:
maxIdx.1_15 = (unsigned int) maxIdx_59;
D.1923_20 = maxIdx.1_15 + 1;
D.1924_21 = D.1923_20 * 4;
D.1925_22 = numbers_9(D) + D.1924_21;
and this:
maxIdx_24 = maxIdx_59 + 1;
pretmp.36_86 = (unsigned int) maxIdx_24;
pretmp.36_88 = pretmp.36_86 * 4;
pretmp.38_90 = numbers_9(D) + pretmp.36_88;
do not match. The first has the arithmetic done as unsigned, the second as
signed. This could be due to array indexing lowered to POINTER_PLUS_EXPR.
--
bonzini at gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org, pinskia at gcc dot gnu
| |dot org
Summary|missed load PRE-like |missed FRE opportunity
|opportunity |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37242