digitalmars.D.bugs - repost: codegen issues with -inline
- "Kris" <someidiot earthlink.dot.dot.dot.net> May 24 2004
- "Walter" <newshound digitalmars.com> May 25 2004
- "Kris" <someidiot earthlink.dot.dot.dot.net> May 25 2004
- "Kris" <someidiot earthlink.dot.dot.dot.net> May 25 2004
- "Walter" <newshound digitalmars.com> May 27 2004
- "Walter" <newshound digitalmars.com> May 25 2004
- "Kris" <someidiot earthlink.dot.dot.dot.net> May 27 2004
- "Walter" <newshound digitalmars.com> May 27 2004
- "Kris" <someidiot earthlink.dot.dot.dot.net> May 27 2004
- "Walter" <newshound digitalmars.com> May 28 2004
(Repost, so it doesn't get lost)
[Here's a binary-chop with an interesting codegen issue. It operates fine
with any compiler flags other than -inline which, when applied, will cause
an access violation.
Compiler flags for the code listing are -g -O -release -inline]
Here's the code:
private static int bsearch (short[] array, short match)
{
int l, u, m;
l = -1;
u = array.length;
while (l+1 != u)
{
m = (l + u) / 2;
if (array[m] < match)
l = m;
else
u = m;
}
if (u >= array.length || array[u] != match)
return -u;
return u;
}
static int lookup (short target)
{
short index = bsearch (primes, target);
if (index < 0)
index = -index;
if (index >= primes.length)
index = primes.length - 1;
return primes[index];
}
The caller looks like this:
this (FileBucket bucket, int capacity)
{
super (Primes.lookup (capacity));
<snip>
}
Taking a closer look, the -inline is inlining an instance of the lookup()
method, but passing invalid arguments to the bsearch() method.
GPFs caused by bogus codegen aside, the lookup() method is a seriously poor
candidate for inlining. Perhaps D needs to expose more control over such
things?
- Kris
May 24 2004
Can you make a fully compilable example, please? The reasons are: 1) frequently the real problem is in the stuff snipped out. 2) it's a fair amount of work to invent the boilerplate needed to compile it. If you already have it, please leave it in - and I hate doing this only to find out that (1) was the problem. 3) when done, it makes for a nice addition to the tests I run D through for every release.
May 25 2004
Sure Walter; just download the Mango tree from dsource.org :-) Seriously though; I'm vaguely concerned that some shortening will cause your -inline algorithm to change strategy. Will give it a shot tomorrow, and send you the resulting code. BTW, how sensitive are your D hash algorithms to prime numbers? Nada? Some? Seriously so? - Kris "Walter" <newshound digitalmars.com> wrote in message news:c8uup3$303e$1 digitaldaemon.com...Can you make a fully compilable example, please? The reasons are: 1) frequently the real problem is in the stuff snipped out. 2) it's a fair amount of work to invent the boilerplate needed to compile it. If you already have it, please leave it in - and I hate doing this
to find out that (1) was the problem. 3) when done, it makes for a nice addition to the tests I run D through
every release.
May 25 2004
Here you go Walter: dmd -O -release -inline primes.d inlineBug.d (see attached files)"Walter" <newshound digitalmars.com> wrote Can you make a fully compilable example, please?
May 25 2004
"Walter" <newshound digitalmars.com> Thanks. It'll get fixed in the next update. "Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c90cmf$28r5$1 digitaldaemon.com...Here you go Walter: dmd -O -release -inline primes.d inlineBug.d (see attached files)"Walter" <newshound digitalmars.com> wrote Can you make a fully compilable example, please?
May 27 2004
"Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c8v0mb$1ag$1 digitaldaemon.com...BTW, how sensitive are your D hash algorithms to prime numbers? Nada?
Seriously so?
??
May 25 2004
I meant, does the .length of an associative array impact the performance of the algorithms? Some hashing algorithms favour prime array-lengths ... Am I completely off base here? - Kris "Walter" <newshound digitalmars.com> wrote in message news:c9185v$gj6$1 digitaldaemon.com..."Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c8v0mb$1ag$1 digitaldaemon.com...BTW, how sensitive are your D hash algorithms to prime numbers? Nada?
Seriously so?
??
May 27 2004
"Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c95knj$1oss$1 digitaldaemon.com...I meant, does the .length of an associative array impact the performance
the algorithms? Some hashing algorithms favour prime array-lengths ... Am I completely off base here?
Most of the time, I doubt you'll notice any difference.
May 27 2004
LOL! The "Am I completely off base here?" and your answer make a much better combination than the original question :-) "Walter" <newshound digitalmars.com> wrote in message news:c96dut$2tp8$1 digitaldaemon.com..."Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c95knj$1oss$1 digitaldaemon.com...I meant, does the .length of an associative array impact the performance
the algorithms? Some hashing algorithms favour prime array-lengths ... Am I completely off base here?
Most of the time, I doubt you'll notice any difference.
May 27 2004
Arf! You'll never believe me, but I had intended it to apply to the first sentence, not the last <g>. "Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c96f75$309k$1 digitaldaemon.com...LOL! The "Am I completely off base here?" and your answer make a much better combination than the original question :-) "Walter" <newshound digitalmars.com> wrote in message news:c96dut$2tp8$1 digitaldaemon.com..."Kris" <someidiot earthlink.dot.dot.dot.net> wrote in message news:c95knj$1oss$1 digitaldaemon.com...I meant, does the .length of an associative array impact the
ofthe algorithms? Some hashing algorithms favour prime array-lengths ... Am I completely off base here?
Most of the time, I doubt you'll notice any difference.
May 28 2004