Displaying 5 results from an estimated 5 matches for "impliciltly".
2013 May 23
2
[LLVMdev] LLVM Loop Vectorizer puzzle
...ations. Obviously this may not
always be a win, but I'm just wondering if there's a way to communicate
this intent and get around the vectorizer-min-trip-count in specially
desired cases, or if I should decide to generate vectorized IR directly.
(This is in code coming from a DSL which will impliciltly insert
annotations, not manually written loops.)
Cheers,
Dave
On Thu, May 23, 2013 at 5:06 AM, Arnold Schwaighofer <
aschwaighofer at apple.com> wrote:
> Hi,
>
> The TinyTripCountVectorThreshold only applies to loops with a known
> (constant) trip count. If a loop has a trip...
2013 May 23
0
[LLVMdev] LLVM Loop Vectorizer puzzle
...is may not always be a win, but I'm just
> wondering if there's a way to communicate this intent and get around
> the vectorizer-min-trip-count in specially desired cases, or if I
> should decide to generate vectorized IR directly. (This is in code
> coming from a DSL which will impliciltly insert annotations, not
> manually written loops.)
>
I think that the answer is: not currently. On the other hand, if the loop is small enough to get unrolled, then you can either use the BB vectorization pass or the SLP vectorization pass to vectorize it.
-Hal
> Cheers,
> Dave
>...
2013 May 23
2
[LLVMdev] LLVM Loop Vectorizer puzzle
...s be a win, but I'm just
>> wondering if there's a way to communicate this intent and get around
>> the vectorizer-min-trip-count in specially desired cases, or if I
>> should decide to generate vectorized IR directly. (This is in code
>> coming from a DSL which will impliciltly insert annotations, not
>> manually written loops.)
>>
>
> I think that the answer is: not currently. On the other hand, if the loop is small enough to get unrolled, then you can either use the BB vectorization pass or the SLP vectorization pass to vectorize it.
Yes.
I would l...
2013 May 23
0
[LLVMdev] LLVM Loop Vectorizer puzzle
Hi,
The TinyTripCountVectorThreshold only applies to loops with a known (constant) trip count. If a loop has a trip count below this value we don’t attempt to vectorize the loop. The loop below has an unknown trip count.
Once we decide to vectorize a loop, we emit code to check whether we can execute one iteration of the vectorized body. This is the code quoted below.
On May 22, 2013, at 10:23
2013 May 23
2
[LLVMdev] LLVM Loop Vectorizer puzzle
Hi,
I have the llvm loop vectorizer to complie the following sample:
//=================
int test(int *a, int n) {
for(int i = 0; i < n; i++) {
a[i] += i;
}
return 0;
}
//================
The corresponded .ll file has a loop preheader:
//================
for.body.lr.ph: ; preds = %entry