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[Bug rtl-optimization/15792] missed subreg optimization
- From: "dann at godzilla dot ics dot uci dot edu" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 20 Aug 2004 18:47:07 -0000
- Subject: [Bug rtl-optimization/15792] missed subreg optimization
- References: <20040603042727.15792.pinskia@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From dann at godzilla dot ics dot uci dot edu 2004-08-20 18:47 -------
(In reply to comment #1)
> Indeed. In test1, we get a completely bogus sequence:
> movl 12(%ebp), %edx
> movl 8(%ebp), %eax
> movl %edx, %ecx
> orl %eax, %ecx
> What is the compiler thinking, moving data first into adx just to move
> it further into ecx the next moment?
This is a regression from gcc-3.0, the mov is not generated there:
movl 16(%esp), %eax
movl 20(%esp), %edx
orl %edx, %eax
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15792