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[Bug rtl-optimization/19597] New: avr-gcc 4.0, multiplication by constant, very long code
- From: "dmixm at marine dot febras dot ru" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 23 Jan 2005 22:55:39 -0000
- Subject: [Bug rtl-optimization/19597] New: avr-gcc 4.0, multiplication by constant, very long code
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
avr-gcc 4.0 (20050116) replaces multiplication by a constant to a combination of more simple
operations. Thus it does not pay attention to efficiency of such replacement.
For example:
int foo (int x) { return 24011 * x; }
produce 49 words (-mmcu=atmega8 -Os).
Older GCC branches -- only 11 words in this case.
--
Summary: avr-gcc 4.0, multiplication by constant, very long code
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dmixm at marine dot febras dot ru
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19597
- Follow-Ups:
- [Bug middle-end/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: pinskia at gcc dot gnu dot org
- [Bug middle-end/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: giovannibajo at libero dot it
- [Bug middle-end/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: bernie at develer dot com
- [Bug middle-end/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: roger at eyesopen dot com
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: pinskia at gcc dot gnu dot org
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: giovannibajo at libero dot it
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: marekm at amelek dot gda dot pl
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: bernie at develer dot com
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: bernie at develer dot com
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: schlie at comcast dot net
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: roger at eyesopen dot com
- [Bug target/19597] [4.0 Regression] avr-gcc 4.0, multiplication by constant, very long code
- From: schlie at comcast dot net