OpenACC as a concept of loop independence, in which independent loops
may be executed in parallel across gangs, workers and vectors. Inside
acc parallel regions, if a loop isn't explicitly marked seq or auto, it
is predetermined to be independent.
This patch corrects a bug where acc loops marked as auto were being
mistakenly promoted to independent. That's bad because it can generate
bogus results if a dependency exist.
Note that this patch depends on the following patches for
-fnote-info-omp-optimized which is used in a test case.
* Add user-friendly OpenACC diagnostics regarding detected
parallelism.
https://gcc.gnu.org/ml/gcc-patches/2018-07/msg01652.html
* Correct the reported line number in fortran combined OpenACC
directives
https://gcc.gnu.org/ml/gcc-patches/2018-07/msg01554.html
* Correct the reported line number in c++ combined OpenACC directives
https://gcc.gnu.org/ml/gcc-patches/2018-07/msg01552.html
Is this OK for trunk? I bootstrapped and regtested on x86_64 Linux with
nvptx offloading.
Thanks,
Cesar
[OpenACC] Don't mark OpenACC auto loops as independent inside acc parallel regions
2018-XX-YY Cesar Philippidis <ce...@codesourcery.com>
gcc/
* omp-low.c (lower_oacc_head_mark): Don't mark OpenACC auto
loops as independent inside acc parallel regions.
gcc/testsuite/
* c-c++-common/goacc/loop-auto-1.c: Adjust test case to conform to
the new behavior of the auto clause in OpenACC 2.5.
* c-c++-common/goacc/loop-auto-2.c: Likewise.
* gcc.dg/goacc/loop-processing-1.c: Likewise.
* c-c++-common/goacc/loop-auto-3.c: New test.
* gfortran.dg/goacc/loop-auto-1.f90: New test.
libgomp/
* testsuite/libgomp.oacc-c-c++-common/loop-auto-1.c: Adjust test case
to conform to the new behavior of the auto clause in OpenACC 2.5.
(cherry picked from gomp-4_0-branch r247569, 6d30b542f29)
---
gcc/omp-low.c | 5 +-
.../c-c++-common/goacc/loop-auto-1.c | 50 +++++------
.../c-c++-common/goacc/loop-auto-2.c | 4 +-
.../c-c++-common/goacc/loop-auto-3.c | 78 ++++++++++++++++
.../gcc.dg/goacc/loop-processing-1.c | 2 +-
.../gfortran.dg/goacc/loop-auto-1.f90 | 88 +++++++++++++++++++
.../libgomp.oacc-c-c++-common/loop-auto-1.c | 20 ++---
7 files changed, 207 insertions(+), 40 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/goacc/loop-auto-3.c
create mode 100644 gcc/testsuite/gfortran.dg/goacc/loop-auto-1.f90
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index fdabf67249b..24685fd012c 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -5647,9 +5647,10 @@ lower_oacc_head_mark (location_t loc, tree ddvar, tree clauses,
tag |= OLF_GANG_STATIC;
}
- /* In a parallel region, loops are implicitly INDEPENDENT. */
+ /* In a parallel region, loops without auto and seq clauses are
+ implicitly INDEPENDENT. */
omp_context *tgt = enclosing_target_ctx (ctx);
- if (!tgt || is_oacc_parallel (tgt))
+ if ((!tgt || is_oacc_parallel (tgt)) && !(tag & (OLF_SEQ | OLF_AUTO)))
tag |= OLF_INDEPENDENT;
if (tag & OLF_TILE)
diff --git a/gcc/testsuite/c-c++-common/goacc/loop-auto-1.c b/gcc/testsuite/c-c++-common/goacc/loop-auto-1.c
index 124befc4002..dcad07f11c8 100644
--- a/gcc/testsuite/c-c++-common/goacc/loop-auto-1.c
+++ b/gcc/testsuite/c-c++-common/goacc/loop-auto-1.c
@@ -10,7 +10,7 @@ void Foo ()
#pragma acc loop seq
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++) {}
}
@@ -20,7 +20,7 @@ void Foo ()
#pragma acc loop auto
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++)
{
#pragma acc loop vector
@@ -51,7 +51,7 @@ void Foo ()
#pragma acc loop vector
for (int jx = 0; jx < 10; jx++)
{
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int kx = 0; kx < 10; kx++) {}
}
@@ -64,27 +64,27 @@ void Foo ()
}
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 10; ix++)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < 10; jx++)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int kx = 0; kx < 10; kx++) {}
}
}
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 10; ix++)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < 10; jx++)
{
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int kx = 0; kx < 10; kx++)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int lx = 0; lx < 10; lx++) {}
}
}
@@ -101,7 +101,7 @@ void Gang (void)
#pragma acc loop seq
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++) {}
}
@@ -111,7 +111,7 @@ void Gang (void)
#pragma acc loop auto
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++)
{
#pragma acc loop vector
@@ -142,7 +142,7 @@ void Gang (void)
#pragma acc loop vector
for (int jx = 0; jx < 10; jx++)
{
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int kx = 0; kx < 10; kx++) {}
}
@@ -176,7 +176,7 @@ void Worker (void)
#pragma acc loop seq
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++) {}
}
@@ -186,7 +186,7 @@ void Worker (void)
#pragma acc loop auto
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++)
{
#pragma acc loop vector
@@ -194,20 +194,20 @@ void Worker (void)
}
}
-#pragma acc loop auto
+#pragma acc loop
for (int ix = 0; ix < 10; ix++)
{
-#pragma acc loop auto
+#pragma acc loop
for (int jx = 0; jx < 10; jx++) {}
}
-#pragma acc loop auto
+#pragma acc loop
for (int ix = 0; ix < 10; ix++)
{
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++)
{
-#pragma acc loop auto
+#pragma acc loop
for (int kx = 0; kx < 10; kx++) {}
}
}
@@ -222,17 +222,17 @@ void Vector (void)
#pragma acc loop seq
for (int jx = 0; jx < 10; jx++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++) {}
}
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 10; ix++) {}
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int ix = 0; ix < 10; ix++)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < 10; jx++) {}
}
}
@@ -240,6 +240,6 @@ void Vector (void)
#pragma acc routine seq
void Seq (void)
{
-#pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int ix = 0; ix < 10; ix++) {}
}
diff --git a/gcc/testsuite/c-c++-common/goacc/loop-auto-2.c b/gcc/testsuite/c-c++-common/goacc/loop-auto-2.c
index af3f0bddf2c..5aa36e93ab8 100644
--- a/gcc/testsuite/c-c++-common/goacc/loop-auto-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/loop-auto-2.c
@@ -72,12 +72,12 @@ void Bad ()
#pragma acc loop tile(*) gang vector
for (int ix = 0; ix < 10; ix++)
{
- #pragma acc loop auto /* { dg-warning "insufficient partitioning" } */
+ #pragma acc loop auto independent /* { dg-warning "insufficient partitioning" } */
for (int jx = 0; jx < 10; jx++)
;
}
-#pragma acc loop tile(*) auto /* { dg-warning "insufficient partitioning" } */
+#pragma acc loop tile(*) auto independent /* { dg-warning "insufficient partitioning" } */
for (int ix = 0; ix < 10; ix++)
{
#pragma acc loop worker
diff --git a/gcc/testsuite/c-c++-common/goacc/loop-auto-3.c b/gcc/testsuite/c-c++-common/goacc/loop-auto-3.c
new file mode 100644
index 00000000000..5826967240e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/loop-auto-3.c
@@ -0,0 +1,78 @@
+/* Ensure that the auto clause falls back to seq parallelism when the
+ OpenACC loop is not explicitly independent. */
+
+/* { dg-additional-options "-fopt-info-optimized-omp" } */
+
+void
+test ()
+{
+ int i, j, k, l, n = 100;
+
+#pragma acc parallel loop auto /* { dg-message "Detected parallelism <acc loop seq>" } */
+ for (i = 0; i < n; i++)
+#pragma acc loop auto independent /* { dg-message "Detected parallelism <acc loop gang>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop worker vector /* { dg-message "Detected parallelism <acc loop worker vector>" } */
+ for (k = 0; k < n; k++)
+ ;
+
+#pragma acc parallel loop auto independent /* { dg-message "Detected parallelism <acc loop gang worker>" } */
+ for (i = 0; i < n; i++)
+#pragma acc loop auto /* { dg-message "Detected parallelism <acc loop seq>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop auto /* { dg-message "Detected parallelism <acc loop seq>" } */
+ for (k = 0; k < n; k++)
+#pragma acc loop auto independent /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (l = 0; l < n; l++)
+ ;
+
+#pragma acc parallel loop gang /* { dg-message "Detected parallelism <acc loop gang>" } */
+ for (i = 0; i < n; i++)
+#pragma acc loop worker /* { dg-message "Detected parallelism <acc loop worker>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop vector /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (k = 0; k < n; k++)
+ {
+#pragma acc loop auto independent /* { dg-message "Detected parallelism <acc loop seq>" } */
+ /* { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 } */
+ for (l = 0; l < n; l++)
+ ;
+#pragma acc loop auto /* { dg-message "Detected parallelism <acc loop seq>" } */
+ for (l = 0; l < n; l++)
+ ;
+ }
+
+#pragma acc parallel loop /* { dg-message "Detected parallelism <acc loop seq>" } */
+ /* { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 } */
+ for (i = 0; i < n; i++)
+ {
+#pragma acc loop gang worker /* { dg-message "Detected parallelism <acc loop gang worker>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop auto /* { dg-message "Detected parallelism <acc loop seq>" } */
+ for (k = 0; k < n; k++)
+ {
+#pragma acc loop vector /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (l = 0; l < n; l++)
+ ;
+#pragma acc loop auto independent /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (l = 0; l < n; l++)
+ ;
+ }
+#pragma acc loop worker /* { dg-message "Detected parallelism <acc loop worker>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop vector /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (k = 0; k < n; k++)
+ ;
+ }
+
+#pragma acc parallel loop /* { dg-message "Detected parallelism <acc loop gang>" } */
+ for (i = 0; i < n; i++)
+#pragma acc loop /* { dg-message "Detected parallelism <acc loop worker>" } */
+ for (j = 0; j < n; j++)
+#pragma acc loop /* { dg-message "Detected parallelism <acc loop seq>" } */
+ /* { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 } */
+ for (k = 0; k < n; k++)
+#pragma acc loop /* { dg-message "Detected parallelism <acc loop vector>" } */
+ for (l = 0; l < n; l++)
+ ;
+}
diff --git a/gcc/testsuite/gcc.dg/goacc/loop-processing-1.c b/gcc/testsuite/gcc.dg/goacc/loop-processing-1.c
index bd4c07e7d81..7ba61e53012 100644
--- a/gcc/testsuite/gcc.dg/goacc/loop-processing-1.c
+++ b/gcc/testsuite/gcc.dg/goacc/loop-processing-1.c
@@ -9,7 +9,7 @@ void vector_1 (int *ary, int size)
{
#pragma acc loop gang
for (int jx = 0; jx < 1; jx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < size; ix++)
ary[ix] = place ();
}
diff --git a/gcc/testsuite/gfortran.dg/goacc/loop-auto-1.f90 b/gcc/testsuite/gfortran.dg/goacc/loop-auto-1.f90
new file mode 100644
index 00000000000..a8fadf504bc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/goacc/loop-auto-1.f90
@@ -0,0 +1,88 @@
+! Ensure that the auto clause falls back to seq parallelism when the
+! OpenACC loop is not explicitly independent.
+
+! { dg-additional-options "-fopt-info-optimized-omp" }
+
+program test
+ implicit none
+ integer, parameter :: n = 100
+ integer i, j, k, l
+
+ !$acc parallel loop auto ! { dg-message "Detected parallelism <acc loop seq>" }
+ do i = 1, n
+ !$acc loop auto independent ! { dg-message "Detected parallelism <acc loop gang>" }
+ do j = 1, n
+ !$acc loop worker vector ! { dg-message "Detected parallelism <acc loop worker vector>" }
+ do k = 1, n
+ end do
+ end do
+ end do
+
+ !$acc parallel loop auto independent ! { dg-message "Detected parallelism <acc loop gang worker>" }
+ do i = 1, n
+ !$acc loop auto ! { dg-message "Detected parallelism <acc loop seq>" }
+ do j = 1, n
+ !$acc loop auto ! { dg-message "Detected parallelism <acc loop seq>" }
+ do k = 1, n
+ !$acc loop auto independent ! { dg-message "Detected parallelism <acc loop vector>" }
+ do l = 1, n
+ end do
+ end do
+ end do
+ end do
+
+ !$acc parallel loop gang ! { dg-message "Detected parallelism <acc loop gang>" }
+ do i = 1, n
+ !$acc loop worker ! { dg-message "Detected parallelism <acc loop worker>" }
+ do j = 1, n
+ !$acc loop vector ! { dg-message "Detected parallelism <acc loop vector>" }
+ do k = 1, n
+ !$acc loop auto independent ! { dg-message "Detected parallelism <acc loop seq>" }
+ ! { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 }
+ do l = 1, n
+ end do
+ !$acc loop auto ! { dg-message "Detected parallelism <acc loop seq>" }
+ do l = 1, n
+ end do
+ end do
+ end do
+ end do
+
+
+ !$acc parallel loop ! { dg-message "Detected parallelism <acc loop seq>" }
+ ! { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 }
+ do i = 1, n
+ !$acc loop gang worker ! { dg-message "Detected parallelism <acc loop gang worker>" }
+ do j = 1, n
+ !$acc loop auto ! { dg-message "Detected parallelism <acc loop seq>" }
+ do k = 1, n
+ !$acc loop vector ! { dg-message "Detected parallelism <acc loop vector>" }
+ do l = 1, n
+ end do
+ end do
+ !$acc loop auto independent ! { dg-message "Detected parallelism <acc loop vector>" }
+ do l = 1, n
+ end do
+ end do
+ !$acc loop worker ! { dg-message "Detected parallelism <acc loop worker>" }
+ do j = 1, n
+ !$acc loop vector ! { dg-message "Detected parallelism <acc loop vector>" }
+ do k = 1, n
+ end do
+ end do
+ end do
+
+ !$acc parallel loop ! { dg-message "Detected parallelism <acc loop gang>" }
+ do i = 1, n
+ !$acc loop ! { dg-message "Detected parallelism <acc loop worker>" }
+ do j = 1, n
+ !$acc loop ! { dg-message "Detected parallelism <acc loop seq>" }
+ ! { dg-warning "insufficient partitioning available to parallelize loop" "" { target *-*-* } .-1 }
+ do k = 1, n
+ !$acc loop ! { dg-message "Detected parallelism <acc loop vector>" }
+ do l = 1, n
+ end do
+ end do
+ end do
+ end do
+end program test
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-auto-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-auto-1.c
index 34bc57e51f5..cfb18d11acd 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-auto-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/loop-auto-1.c
@@ -101,7 +101,7 @@ int vector_1 (int *ary, int size)
{
#pragma acc loop gang
for (int jx = 0; jx < 1; jx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < size; ix++)
ary[ix] = place ();
}
@@ -117,7 +117,7 @@ int vector_2 (int *ary, int size)
{
#pragma acc loop worker
for (int jx = 0; jx < size / 64; jx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 64; ix++)
ary[ix + jx * 64] = place ();
}
@@ -133,7 +133,7 @@ int worker_1 (int *ary, int size)
{
#pragma acc loop gang
for (int kx = 0; kx < 1; kx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < size / 64; jx++)
#pragma acc loop vector
for (int ix = 0; ix < 64; ix++)
@@ -149,7 +149,7 @@ int gang_1 (int *ary, int size)
#pragma acc parallel num_gangs (32) num_workers (32) vector_length(32) copy(ary[0:size]) firstprivate (size)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < size / 64; jx++)
#pragma acc loop worker
for (int ix = 0; ix < 64; ix++)
@@ -165,11 +165,11 @@ int gang_2 (int *ary, int size)
#pragma acc parallel num_gangs (32) num_workers (32) vector_length(32) copy(ary[0:size]) firstprivate (size)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int kx = 0; kx < size / (32 * 32); kx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < 32; jx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 32; ix++)
ary[ix + jx * 32 + kx * 32 * 32] = place ();
}
@@ -183,9 +183,9 @@ int gang_3 (int *ary, int size)
#pragma acc parallel num_workers (32) vector_length(32) copy(ary[0:size]) firstprivate (size)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < size / 64; jx++)
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int ix = 0; ix < 64; ix++)
ary[ix + jx * 64] = place ();
}
@@ -199,7 +199,7 @@ int gang_4 (int *ary, int size)
#pragma acc parallel vector_length(32) copy(ary[0:size]) firstprivate (size)
{
-#pragma acc loop auto
+#pragma acc loop auto independent
for (int jx = 0; jx < size; jx++)
ary[jx] = place ();
}
--
2.17.1
