avr-gcc-list-requ...@nongnu.org wrote:
>>> OK, I only spent a few minutes looking at old code and I found some
>>> obviously sub-optimal results. It distills down to this:
>>>
>>> #include
>>>
>>> int main(void) {
>>> unsigned long packet = 0;
>>>
>>> while(1) {
>>> if( !(PINC & _BV(PC2))
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Vincent Trouilliez
> Sent: Saturday, February 28, 2009 7:41 PM
> To: avr-gcc-list@nongnu.org
> Subject: Re: [avr
On Sat, 28 Feb 2009 19:24:38 -0700
"Weddington, Eric" wrote:
> You wouldn't need *nested* ifs, but an if-else-if structure, or better yet, a
> table of function pointers, also known as a dispatch table. Each method
> depends on the type of data that you're switching on.
I switch on an unsigned
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Vincent Trouilliez
> Sent: Saturday, February 28, 2009 7:20 PM
> To: avr-gcc-list@nongnu.org
> Subject: Re: [avr
On Sat, 28 Feb 2009 19:09:13 -0700
"Weddington, Eric" wrote:
> So in application code I tend to avoid switch statements for embedded
> systems, unless I'm writing throw-away code or the application is trivial.
Oh no ! ;-)
I have only recently got round to using switch statements, to improve
cod
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Bob Paddock
> Sent: Saturday, February 28, 2009 6:40 PM
> To: avr-gcc-list@nongnu.org
> Subject: Re: [avr-gcc-li
> In practice, the experienced programmer can do a lot to help
> the tools. avr-gcc *does* do a good job with most code - I do
> much less re-structuring of my source code for avr-gcc than I do
> for most other compilers (I use a lot of compilers for a lot of >different
> targets).
Something I a
Georg-Johann Lay wrote:
David Brown schrieb:
Nicholas Vinen wrote:
OK, I only spent a few minutes looking at old code and I found some
obviously sub-optimal results. It distills down to this:
#include
int main(void) {
unsigned long packet = 0;
while(1) {
if( !(PINC & _BV(PC2)) ) {
David Brown schrieb:
Nicholas Vinen wrote:
OK, I only spent a few minutes looking at old code and I found some
obviously sub-optimal results. It distills down to this:
#include
int main(void) {
unsigned long packet = 0;
while(1) {
if( !(PINC & _BV(PC2)) ) {
packet = (packet<<
>
> Unless your "big iron" guys are similarly inexperienced (being a beginner
> is a good excuse for many mistakes), then they are incompetent. There is
> *no* excuse for a knowledgeable programmer using an inefficient and unsafe
> function in such a horribly unclear manner
I disagree, but I'm
Nicholas Vinen wrote:
OK, I only spent a few minutes looking at old code and I found some
obviously sub-optimal results. It distills down to this:
#include
int main(void) {
unsigned long packet = 0;
while(1) {
if( !(PINC & _BV(PC2)) ) {
packet = (packet<<1)|(((unsigned char)PIN
David VanHorn wrote:
> has exactly the same effect as:
>
> A_String[i] = 0xff;
> A_String[i + 1] = 0x00;
> delay_about_1000_processor_cycles();
> waste_about_2000_bytes_of_code_space();
ROTF ! :-
As was earlier, and more gently poin
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of David Brown
> Sent: Saturday, February 28, 2009 12:49 PM
> To: avr-gcc-list@nongnu.org
> Subject: [avr-gcc-list]
Daniel O'Connor wrote:
On Saturday 28 February 2009 09:00:50 David Kelly wrote:
On Fri, Feb 27, 2009 at 10:37:30PM +0100, Vincent Trouilliez wrote:
On Fri, 27 Feb 2009 22:10:16 +0100
David Brown wrote:
sprintf((A_String + i), "%c", 0xff)
has exactly the same effect as:
A_St
Hi Eric,
thanks for the extremely fast replies!
On Sat, Feb 28, 2009 at 9:09 PM, Weddington, Eric
wrote:
> Used this command line:
> avr-gcc -Os -mmcu=atmega8 -c ATmegaBOOT.c -DF_CPU=800UL -o ATmegaBOOT.o
> No warnings, no errors.
> Using avr-gcc 4.3.2.
I have found the problem in my Makefi
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Radoslav Kolev
> Sent: Saturday, February 28, 2009 11:55 AM
> To: avr-gcc-list@nongnu.org
> Subject: [avr-gcc-li
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Radoslav Kolev
> Sent: Saturday, February 28, 2009 11:55 AM
> To: avr-gcc-list@nongnu.org
> Subject: [avr-gcc-li
On Sat, Feb 28, 2009 at 8:09 PM, Weddington, Eric
wrote:
> Are you including or ?
Yes, is included. I'm attaching the complete .c file.
> And please stop using inb() and outb(). They have been removed from avr-libc
> and are not necessary. Just use a regular assignment.
I know. I didn't writ
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Radoslav Kolev
> Sent: Saturday, February 28, 2009 10:51 AM
> To: avr-gcc-list@nongnu.org
> Subject: [avr-gcc-li
Hello!
I wanted to rebuild the Arduino Atmega8 bootloader using avr-gcc
4.2.2, installed from the Ubuntu 8.04.1 packages.
At first I run against the problem of 4.x gcc versions producing
bigger code, compared to 3.x versions that doesn't fit in the 1k boot
loader space. The bug report is here
htt
> -Original Message-
> From: Georg-Johann Lay [mailto:a...@gjlay.de]
> Sent: Saturday, February 28, 2009 10:09 AM
> To: Weddington, Eric
> Cc: Nicholas Vinen; avr-gcc-list@nongnu.org
> Subject: Re: [avr-gcc-list] Re: C vs. assembly performance
>
> Weddington, Eric schrieb:
>
> BTW, is
Weddington, Eric schrieb:
-Original Message-
From:
avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
[mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
org] On Behalf Of Georg-Johann Lay
Sent: Saturday, February 28, 2009 9:00 AM
To: Nicholas Vinen
Cc: avr-gcc-l
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Georg-Johann Lay
> Sent: Saturday, February 28, 2009 9:00 AM
> To: Nicholas Vinen
> Cc: avr-gcc-list@nongnu.org
Nicholas Vinen schrieb:
Georg-Johann Lay wrote:
If you are sure it is really some performance issue/regression and not
due to some language standard implication, you can add a report to
http://sourceforge.net/tracker/?group_id=68108
so that the subject won't be forgotten. Also mind
http:
> -Original Message-
> From:
> avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.org
> [mailto:avr-gcc-list-bounces+eweddington=cso.atmel@nongnu.
> org] On Behalf Of Nicholas Vinen
> Sent: Saturday, February 28, 2009 6:21 AM
> To: partha_nay...@yahoo.com
> Cc: avr-gcc-list@nong
Georg-Johann Lay wrote:
> If you are sure it is really some performance issue/regression and not
> due to some language standard implication, you can add a report to
> http://sourceforge.net/tracker/?group_id=68108
>
> so that the subject won't be forgotten. Also mind
> http://gcc.gnu.org/b
Georg-Johann Lay wrote:
> compiling the following code
> unsigned char sh4 (unsigned char x)
> {
> return x >> 4;
> }
>
> unsigned char sh8 (unsigned short x)
> {
> return x >> 8;
> }
>
> with avr-gcc 4.3.2 and -Os yields (non-code stripped)
>
> sh4:
> swap r24 ;
> andi r24,lo8(
Parthasaradhi Nayani wrote:
>
>> From: Nicholas Vinen
>>
>
> For example, things like "unsigned char x, y;
>
>> x = y>>4" could
>> use the nibble swap instruction rather than four shifts,
>> and things like
>>
>
> Shifting a byte or int right or left must push in 00s from the othe
Nicholas Vinen schrieb:
* On the other hand, it would be great if avr-gcc could perform some
basic optimisations that even a fairly inexperienced amateur could
manage. For example, things like "unsigned char x, y; x = y>>4" could
use the nibble swap instruction rather than four shifts, and things
> From: Nicholas Vinen
For example, things like "unsigned char x, y;
> x = y>>4" could
> use the nibble swap instruction rather than four shifts,
> and things like
Shifting a byte or int right or left must push in 00s from the other side so
swapping a nibble is not the right thing to do. So
> If I wanted fast and small, I'd have done it in ASM. But half of the point
> of this exercise was to get my feet wet with C.
> So, both points accomplished. I have GCC up under AVR studio, a working
> project, and I feel reasonably confident with the code.
>
Despite avr-gcc being fairly dim a
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