Re: [gomp4] Generate sequential loop for OpenACC loop directive inside kernels

[Chung-Lin Tang]

On 2015/6/16 05:05 PM, Tom de Vries wrote:
 On 16/06/15 10:59, Chung-Lin Tang wrote:
 This patch adjusts omp-low.c:expand_omp_for_generic() to expand to a 
 sequential
 loop form (without the OMP runtime calls), used for loop directives inside
 OpenACC kernels constructs. Tom mentions that this allows the kernels 
 parallelization
 to work when '#pragma acc loop' makes the front-ends create OMP_FOR, which 
 the
 loop analysis phases don't understand.

 Tested and committed to gomp-4_0-branch.

 
 Hi Chung-Lin,
 
 can you commit a test-case to exercise the code?
 
 Thanks,
 - Tom

Just committed the attached testcase patch to gomp-4_0-branch.

Chung-Lin

2015-06-23  Chung-Lin Tang  clt...@codesourcery.com

gcc/testsuite/
* c-c++-common/goacc/kernels-loop.c (ACC_LOOP): Add #ifndef/#define.
(main): Tag loops inside kernels construct with '#pragma ACC_LOOP'.
* c-c++-common/goacc/kernels-loop-2.c: Likewise.
* c-c++-common/goacc/kernels-loop-3.c: Likewise.
* c-c++-common/goacc/kernels-loop-n.c: Likewise.
* c-c++-common/goacc/kernels-loop-acc-loop.c: New test.
* c-c++-common/goacc/kernels-loop-2-acc-loop.c: New test.
* c-c++-common/goacc/kernels-loop-3-acc-loop.c: New test.
* c-c++-common/goacc/kernels-loop-n-acc-loop.c: New test.

Index: gcc/testsuite/c-c++-common/goacc/kernels-loop-3-acc-loop.c
===
--- gcc/testsuite/c-c++-common/goacc/kernels-loop-3-acc-loop.c	(revision 0)
+++ gcc/testsuite/c-c++-common/goacc/kernels-loop-3-acc-loop.c	(revision 0)
@@ -0,0 +1,20 @@
+/* { dg-additional-options -O2 } */
+/* { dg-additional-options -ftree-parallelize-loops=32 } */
+/* { dg-additional-options -fdump-tree-parloops_oacc_kernels-all } */
+/* { dg-additional-options -fdump-tree-optimized } */
+
+/* Check that loops with '#pragma acc loop' tagged gets properly parallelized.  */
+#define ACC_LOOP acc loop
+#include kernels-loop-3.c
+
+/* Check that only one loop is analyzed, and that it can be parallelized.  */
+/* { dg-final { scan-tree-dump-times SUCCESS: may be parallelized 1 parloops_oacc_kernels } } */
+/* { dg-final { scan-tree-dump-not FAILED: parloops_oacc_kernels } } */
+
+/* Check that the loop has been split off into a function.  */
+/* { dg-final { scan-tree-dump-times (?n);; Function .*main._omp_fn.0 1 optimized } } */
+
+/* { dg-final { scan-tree-dump-times (?n)pragma omp target oacc_parallel.*num_gangs\\(32\\) 1 parloops_oacc_kernels } } */
+
+/* { dg-final { cleanup-tree-dump parloops_oacc_kernels } } */
+/* { dg-final { cleanup-tree-dump optimized } } */
Index: gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c
===
--- gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c	(revision 224836)
+++ gcc/testsuite/c-c++-common/goacc/kernels-loop-2.c	(working copy)
@@ -8,6 +8,10 @@
 #define N (1024 * 512)
 #define COUNTERTYPE unsigned int
 
+#ifndef ACC_LOOP
+#define ACC_LOOP
+#endif
+
 int
 main (void)
 {
@@ -21,18 +25,21 @@ main (void)
 
 #pragma acc kernels copyout (a[0:N])
   {
+#pragma ACC_LOOP
 for (COUNTERTYPE i = 0; i  N; i++)
   a[i] = i * 2;
   }
 
 #pragma acc kernels copyout (b[0:N])
   {
+#pragma ACC_LOOP
 for (COUNTERTYPE i = 0; i  N; i++)
   b[i] = i * 4;
   }
 
 #pragma acc kernels copyin (a[0:N], b[0:N]) copyout (c[0:N])
   {
+#pragma ACC_LOOP
 for (COUNTERTYPE ii = 0; ii  N; ii++)
   c[ii] = a[ii] + b[ii];
   }
Index: gcc/testsuite/c-c++-common/goacc/kernels-loop.c
===
--- gcc/testsuite/c-c++-common/goacc/kernels-loop.c	(revision 224836)
+++ gcc/testsuite/c-c++-common/goacc/kernels-loop.c	(working copy)
@@ -8,6 +8,10 @@
 #define N (1024 * 512)
 #define COUNTERTYPE unsigned int
 
+#ifndef ACC_LOOP
+#define ACC_LOOP
+#endif
+
 int
 main (void)
 {
@@ -27,6 +31,7 @@ main (void)
 
 #pragma acc kernels copyin (a[0:N], b[0:N]) copyout (c[0:N])
   {
+#pragma ACC_LOOP
 for (COUNTERTYPE ii = 0; ii  N; ii++)
   c[ii] = a[ii] + b[ii];
   }
Index: gcc/testsuite/c-c++-common/goacc/kernels-loop-2-acc-loop.c
===
--- gcc/testsuite/c-c++-common/goacc/kernels-loop-2-acc-loop.c	(revision 0)
+++ gcc/testsuite/c-c++-common/goacc/kernels-loop-2-acc-loop.c	(revision 0)
@@ -0,0 +1,23 @@
+/* { dg-additional-options -O2 } */
+/* { dg-additional-options -ftree-parallelize-loops=32 } */
+/* { dg-additional-options -fdump-tree-parloops_oacc_kernels-all } */
+/* { dg-additional-options -fdump-tree-optimized } */
+
+/* Check that loops with '#pragma acc loop' tagged gets properly parallelized.  */
+#define ACC_LOOP acc loop
+#include kernels-loop-2.c
+
+/* Check that only three loops are analyzed, and that all can be
+   parallelized.  */
+/* { dg-final { scan-tree-dump-times SUCCESS: may be parallelized 3 parloops_oacc_kernels } } */
+/* { dg-final { 

Re: [gomp4] Generate sequential loop for OpenACC loop directive inside kernels

[Tom de Vries]

On 16/06/15 10:59, Chung-Lin Tang wrote:

This patch adjusts omp-low.c:expand_omp_for_generic() to expand to a 
sequential
loop form (without the OMP runtime calls), used for loop directives inside
OpenACC kernels constructs. Tom mentions that this allows the kernels 
parallelization
to work when '#pragma acc loop' makes the front-ends create OMP_FOR, which the
loop analysis phases don't understand.

Tested and committed to gomp-4_0-branch.



Hi Chung-Lin,

can you commit a test-case to exercise the code?

Thanks,
- Tom


Chung-Lin

2015-06-16  Chung-Lin Tang  clt...@codesourcery.com

 * omp-low.c (struct omp_region): Add inside_kernels_p field.
 (expand_omp_for_generic): Adjust to generate a 'sequential' loop
 when GOMP builtin arguments are BUILT_IN_NONE.
 (expand_omp_for): Use expand_omp_for_generic() to generate a
 non-parallelized loop for OMP_FORs inside OpenACC kernels regions.
 (expand_omp): Mark inside_kernels_p field true for regions
 nested inside OpenACC kernels constructs.