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update description and code for examples async_target.2[cf]

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Henry Jin 2015-02-04 23:01:13 -08:00
parent d75aaf49b5
commit 4aa8473543
4 changed files with 27 additions and 7 deletions
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19
Examples_async_target.tex
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@ -24,7 +24,24 @@ accessed.
\cexample{async_target}{2c}
The Fortran example uses allocatable arrays for dynamic memory on the device.
The Fortran example below is similar to the C version above. Instead of pointers, though, it uses
the convenience of Fortran allocatable arrays on the device. An allocatable array has the
same behavior in a \code{map} clause as a C pointer, in this case.
If there is no shape specified for an allocatable array in a \code{map} clause, only the array descriptor
(also called a dope vector) is mapped. That is, device space is created for the descriptor, and it
is initially populated with host values. In this case, the \plc{v1} and \plc{v2} arrays will be in a
non-associated state on the device. When space for \plc{v1} and \plc{v2} is allocated on the device
the addresses to the space will be included in their descriptors.
At the end of the device region, the descriptor (of an unshaped specification of an allocatable
array in a \code{map} clause) is returned with the raw device address of the allocated space.
The content of the array is not returned. In the example the data in arrays \plc{v1} and \plc{v2}
are not returned. In the second target directive, the \plc{v1} and \plc{v2} descriptors are
re-created on the device with the descriptive information; and references to the
vectors point to the correct local storage, of the space that was not freed in the first target
directive. At the end of the \code{target} region the data in array \plc{p} is copied back
to the host, since \plc{p} is not an allocatable array.
\fexample{async_target}{2f}

4
Title_Page.tex
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@ -17,7 +17,7 @@
\vspace{1.0in}
\textbf{Version 4.0.2 -- February, 2015}
\textbf{Version 4.0.2rv1 -- February, 2015}
\end{center}
\end{adjustwidth}
@ -38,5 +38,7 @@ permission of OpenMP Architecture Review Board.\end{adjustwidth}
\thispagestyle{empty}
\phantom{a}
\emph{This page intentionally left blank}
This working version enacted the following tickets: 299, 342, and a few other editorial changes.
\vfill

7
sources/Example_async_target.2c.c
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@ -12,10 +12,11 @@ extern void init(float *, float *, int);
#pragma omp end declare target
extern void foo();
extern void output(float *, int);
void vec_mult(float *p, float *v1, float *v2, int N, int dev)
void vec_mult(float *p, int N, int dev)
{
float *v1, *v2;
int i;
#pragma omp task depend(out: v1, v2)
#pragma omp task shared(v1, v2) depend(out: v1, v2)
#pragma omp target device(dev) map(v1, v2)
{
// check whether on device dev
@ -26,7 +27,7 @@ void vec_mult(float *p, float *v1, float *v2, int N, int dev)
init(v1, v2, N);
}
foo(); // execute other work asychronously
#pragma omp task depend(in: v1, v2)
#pragma omp task shared(v1, v2, p) depend(in: v1, v2)
#pragma omp target device(dev) map(to: v1, v2) map(from: p[0:N])
{
// check whether on device dev

4
sources/Example_async_target.2f.f
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@ -10,7 +10,7 @@
integer :: i, idev
!$omp declare target (init)
!$omp task depend(out: v1,v2)
!$omp task shared(v1,v2) depend(out: v1,v2)
!$omp target device(idev) map(v1,v2)
if( omp_is_initial_device() ) &
stop "not executing on target device"
@ -21,7 +21,7 @@
call foo() ! execute other work asychronously
!$omp task depend(in: v1,v2)
!$omp task shared(v1,v2,p) depend(in: v1,v2)
!$omp target device(idev) map(to: v1,v2) map(from: p)
if( omp_is_initial_device() ) &
stop "not executing on target device"