Displaying 4 results from an estimated 4 matches for "dstsubscript".
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dstsubscripts
2019 May 13
3
Delinearization validity checks in DependenceAnalysis
...record these sizes and add them as
constraints
// to the dependency checks.
for (int i = 1; i < size; ++i) {
if (!isKnownNonNegative(SrcSubscripts[i], SrcPtr))
return false;
if (!isKnownLessThan(SrcSubscripts[i], Sizes[i - 1]))
return false;
if (!isKnownNonNegative(DstSubscripts[i], DstPtr))
return false;
if (!isKnownLessThan(DstSubscripts[i], Sizes[i - 1]))
return false;
}
```
The problem is that in a lot of cases these conditions cannot be proven
statically, even though the delinearized indexes are in fact correct. For
example consider this simple...
2019 May 15
3
Delinearization validity checks in DependenceAnalysis
.../ FIXME: It may be better to record these sizes and add them as
constraints
// to the dependency checks.
for (int i = 1; i < size; ++i) {
if (!isKnownNonNegative(SrcSubscripts[i], SrcPtr))
return false;
if (!isKnownLessThan(SrcSubscripts[i], Sizes[i - 1]))
return false;
if (!isKnownNonNegative(DstSubscripts[i], DstPtr))
return false;
if (!isKnownLessThan(DstSubscripts[i], Sizes[i - 1]))
return false;
}
```
The problem is that in a lot of cases these conditions cannot be proven
statically, even though the delinearized indexes are in fact correct. For
example consider this simple loop:
```
void foo(...
2019 May 16
2
Delinearization validity checks in DependenceAnalysis
...d add them as
> constraints
> // to the dependency checks.
> for (int i = 1; i < size; ++i) {
> if (!isKnownNonNegative(SrcSubscripts[i], SrcPtr))
> return false;
>
> if (!isKnownLessThan(SrcSubscripts[i], Sizes[i - 1]))
> return false;
>
> if (!isKnownNonNegative(DstSubscripts[i], DstPtr))
> return false;
>
> if (!isKnownLessThan(DstSubscripts[i], Sizes[i - 1]))
> return false;
> }
> ```
>
> The problem is that in a lot of cases these conditions cannot be proven
> statically, even though the delinearized indexes are in fact correct. For
>...
2019 May 22
2
Delinearization validity checks in DependenceAnalysis
...j] and A[i*M + j - 1] would get delinearized as follows:
SrcSCEV = {{((4 * %M) + %A)<nsw>,+,(4 * %M)}<%for.body>,+,4}<%for.body4>
DstSCEV = {{(-4 + (4 * %M) + %A),+,(4 * %M)}<%for.body>,+,4}<%for.body4>
SrcSubscripts: {1,+,1}<%for.body>{0,+,1}<%for.body4>
DstSubscripts: {1,+,1}<%for.body>{-1,+,1}<%for.body4> delinearized
subscript 0
src = {1,+,1}<%for.body>
dst = {1,+,1}<%for.body>
class = 1
loops = {1}
subscript 1
src = {0,+,1}<%for.body4>
dst = {-1,+,1}<%for.body4>
class = 1
loops = {2}
Separable = {0 1}
Coupled = {}
Why is...