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[Bug optimization/11864] [3.3/3.4 regression] miscompiles zero extention and test
- From: "amylaar at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 Jan 2004 17:52:59 -0000
- Subject: [Bug optimization/11864] [3.3/3.4 regression] miscompiles zero extention and test
- References: <20030809063003.11864.kkojima@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From amylaar at gcc dot gnu dot org 2004-01-15 17:52 -------
reload_cse_simplify_operands changes a (mem:qi ..) source into a (reg:qi ..).
The source register was set with an SImode set to 0x0000ff00, and the
destination register is used in a SImode equality comparison to zero.
LOAD_EXTEND_OP is SIGN_EXTEND for QImode for this target, hence only
the lower 8 bits of the value should be tested. Thus, the replacement by
reload_cse_simplify_operands is invalid. This bug potentially affects all
targets that define LOAD_EXTEND_OP.
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What |Removed |Added
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Component|target |optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11864