On 2/27/2014 4:22 AM, Kyrill Tkachov wrote:
On 27/02/14 11:07, Andrew Haley wrote:
Over the years there has been a great deal of traffic on these lists
caused by misunderstandings of GCC's inline assembler. That's partly
because it's inherently tricky, but the existing documentation needs
to be improved.
dw <limegreenso...@yahoo.com> has done a fairly thorough reworking of
the documentation. I've helped a bit.
Section 6.41 of the GCC manual has been rewritten. It has become:
6.41 How to Use Inline Assembly Language in C Code
6.41.1 Basic Asm - Assembler Instructions with No Operands
6.41.2 Extended Asm - Assembler Instructions with C Expression Operands
We could simply post the patch to GCC-patches and have at it, but I
think it's better to discuss the document here first. You can read it
at
http://www.LimeGreenSocks.com/gcc/Basic-Asm.html
http://www.LimeGreenSocks.com/gcc/Extended-Asm.html
http://www.LimeGreenSocks.com/gcc/extend04.zip (contains .texi, .patch,
and affected html pages)
All comments are very welcome.
Hi Andrew, dw,
Thanks for doing this!
Thanks for taking the time to review it.
In the Extended Asm documentation: Other format strings section:
"'%=' outputs a number that is unique to each instruction in the
entire compilation."
I find the term 'instruction' to be confusing here. From what I
understand the number is unique to each asm statement, which may
contain multiple assembly instructions. IMHO it would be clearer to
say "unique to each asm statement"
I'm not sure your text quite gets us there either. If (as Richard
suggests), the asm can get duplicated, I'd expect each to get a unique
value for %=. And I'd want to be clear about what happens if you do
#define DO_SOMETHING asm("%=":).
How would you feel about:
"'%=' outputs a number that is unique to each instance of the asm
statement in the entire compilation."
Kyrill
Andrew.
