URL:
<http://savannah.nongnu.org/bugs/?40003>
Summary: Integer type promotion leads to inefficent code in
wdt.h
Project: AVR C Runtime Library
Submitted by: joeymorin
Submitted on: Wed 11 Sep 2013 03:15:33 PM GMT
Category: Library
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Header files
Status: None
Percent Complete: 0%
Assigned to: None
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release: 1.8.0
Fixed Release: None
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Details:
Operands constructed in this fashion:
"r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)),
...result in the use of two registers, one of which is loaded with 0x00 and
never used.
Seems as though integer type promotion is responsible. A fix is as simple as
casting to an 8-bit type:
"r" ((uint8_t)(_BV(_WD_CHANGE_BIT) | _BV(WDE))),
Indeed, most __asm__ statements in wdt.h are already taking this approach, but
a couple are not.
Attached is a patch to resolve the issue.
I'm aware this is a minor issue, but as it is easy to resolve, I hope it will
be accepted :)
Cheers,
JJ
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Wed 11 Sep 2013 03:15:33 PM GMT Name: wdt.h.patch Size: 802B By:
joeymorin
<http://savannah.nongnu.org/bugs/download.php?file_id=29105>
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