re PR middle-end/70895 (OpenACC: loop reduction does not work. Output is zero.)

2016-08-18  Chung-Lin Tang  <cltang@codesourcery.com>

	PR middle-end/70895
	gcc/
	* gimplify.c (omp_add_variable): Adjust/add variable mapping on
	enclosing parallel construct for reduction variables on OpenACC loop
	directives.

	gcc/testsuite/
	* gfortran.dg/goacc/loop-tree-1.f90: Add gimple scan-tree-dump test.
	* c-c++-common/goacc/reduction-1.c: Likewise.
	* c-c++-common/goacc/reduction-2.c: Likewise.
	* c-c++-common/goacc/reduction-3.c: Likewise.
	* c-c++-common/goacc/reduction-4.c: Likewise.

	libgomp/
	* testsuite/libgomp.oacc-fortran/reduction-7.f90: Add explicit
	firstprivate clauses.
	* testsuite/libgomp.oacc-fortran/reduction-6.f90: Remove explicit
	copy clauses.
	* testsuite/libgomp.oacc-c-c++-common/reduction-7.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/reduction-cplx-flt.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/reduction-flt.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/collapse-2.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/loop-red-wv-1.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/collapse-4.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/loop-red-v-1.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/reduction-cplx-dbl.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/loop-red-g-1.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/loop-red-gwv-1.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/loop-red-w-1.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/reduction-dbl.c: Likewise.

From-SVN: r239576

8 files changed, 77 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 505e66e..da65316 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2016-08-18  Chung-Lin Tang  <cltang@codesourcery.com>
+
+	PR middle-end/70895
+	* gimplify.c (omp_add_variable): Adjust/add variable mapping on
+	enclosing parallel construct for reduction variables on OpenACC loop
+	directives.
+
 2016-08-18  Pierre-Marie de Rodat  <derodat@adacore.com>
 
 	* dwarf2out.c (copy_dwarf_procedure): Remove obsolete comment.
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 1e43dbb..4715332 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -6010,6 +6010,45 @@ omp_add_variable (struct gimplify_omp_ctx *ctx, tree decl, unsigned int flags)
     n->value |= flags;
   else
     splay_tree_insert (ctx->variables, (splay_tree_key)decl, flags);
+
+  /* For reductions clauses in OpenACC loop directives, by default create a
+     copy clause on the enclosing parallel construct for carrying back the
+     results.  */
+  if (ctx->region_type == ORT_ACC && (flags & GOVD_REDUCTION))
+    {
+      struct gimplify_omp_ctx *outer_ctx = ctx->outer_context;
+      while (outer_ctx)
+	{
+	  n = splay_tree_lookup (outer_ctx->variables, (splay_tree_key)decl);
+	  if (n != NULL)
+	    {
+	      /* Ignore local variables and explicitly declared clauses.  */
+	      if (n->value & (GOVD_LOCAL | GOVD_EXPLICIT))
+		break;
+	      else if (outer_ctx->region_type == ORT_ACC_KERNELS)
+		{
+		  /* According to the OpenACC spec, such a reduction variable
+		     should already have a copy map on a kernels construct,
+		     verify that here.  */
+		  gcc_assert (!(n->value & GOVD_FIRSTPRIVATE)
+			      && (n->value & GOVD_MAP));
+		}
+	      else if (outer_ctx->region_type == ORT_ACC_PARALLEL)
+		{
+		  /* Remove firstprivate and make it a copy map.  */
+		  n->value &= ~GOVD_FIRSTPRIVATE;
+		  n->value |= GOVD_MAP;
+		}
+	    }
+	  else if (outer_ctx->region_type == ORT_ACC_PARALLEL)
+	    {
+	      splay_tree_insert (outer_ctx->variables, (splay_tree_key)decl,
+				 GOVD_MAP | GOVD_SEEN);
+	      break;
+	    }
+	  outer_ctx = outer_ctx->outer_context;
+	}
+    }
 }
 
 /* Notice a threadprivate variable DECL used in OMP context CTX.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4c7e609..7679928 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2016-08-18  Chung-Lin Tang  <cltang@codesourcery.com>
+
+	PR middle-end/70895
+	* gfortran.dg/goacc/loop-tree-1.f90: Add gimple scan-tree-dump test.
+	* c-c++-common/goacc/reduction-1.c: Likewise.
+	* c-c++-common/goacc/reduction-2.c: Likewise.
+	* c-c++-common/goacc/reduction-3.c: Likewise.
+	* c-c++-common/goacc/reduction-4.c: Likewise.
+
 2016-08-18  Alan Modra  <amodra@gmail.com>
 
 	* gcc.c-torture/compile/pr72771.c: New.
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-1.c b/gcc/testsuite/c-c++-common/goacc/reduction-1.c
index 3c1c2dd..35bfc86 100644
--- a/gcc/testsuite/c-c++-common/goacc/reduction-1.c
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-1.c
@@ -1,3 +1,4 @@
+/* { dg-additional-options "-fdump-tree-gimple" } */
 /* Integer reductions.  */
 
 #define n 1000
@@ -65,3 +66,7 @@ main(void)
 
   return 0;
 }
+
+/* Check that default copy maps are generated for loop reductions.  */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:result \\\[len: \[0-9\]+\\\]\\)" 7 "gimple" } } */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:lresult \\\[len: \[0-9\]+\\\]\\)" 2 "gimple" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-2.c b/gcc/testsuite/c-c++-common/goacc/reduction-2.c
index c3105a2..9dba035 100644
--- a/gcc/testsuite/c-c++-common/goacc/reduction-2.c
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-2.c
@@ -1,3 +1,4 @@
+/* { dg-additional-options "-fdump-tree-gimple" } */
 /* float reductions.  */
 
 #define n 1000
@@ -47,3 +48,7 @@ main(void)
 
   return 0;
 }
+
+/* Check that default copy maps are generated for loop reductions.  */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:result \\\[len: \[0-9\]+\\\]\\)" 4 "gimple" } } */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:lresult \\\[len: \[0-9\]+\\\]\\)" 2 "gimple" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-3.c b/gcc/testsuite/c-c++-common/goacc/reduction-3.c
index 4dbde04..669cd43 100644
--- a/gcc/testsuite/c-c++-common/goacc/reduction-3.c
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-3.c
@@ -1,3 +1,4 @@
+/* { dg-additional-options "-fdump-tree-gimple" } */
 /* double reductions.  */
 
 #define n 1000
@@ -47,3 +48,7 @@ main(void)
 
   return 0;
 }
+
+/* Check that default copy maps are generated for loop reductions.  */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:result \\\[len: \[0-9\]+\\\]\\)" 4 "gimple" } } */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:lresult \\\[len: \[0-9\]+\\\]\\)" 2 "gimple" } } */
diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-4.c b/gcc/testsuite/c-c++-common/goacc/reduction-4.c
index c4572b9..5c3dfb1 100644
--- a/gcc/testsuite/c-c++-common/goacc/reduction-4.c
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-4.c
@@ -1,3 +1,4 @@
+/* { dg-additional-options "-fdump-tree-gimple" } */
 /* complex reductions.  */
 
 #define n 1000
@@ -35,3 +36,7 @@ main(void)
 
   return 0;
 }
+
+/* Check that default copy maps are generated for loop reductions.  */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:result \\\[len: \[0-9\]+\\\]\\)" 2 "gimple" } } */
+/* { dg-final { scan-tree-dump-times "map\\(tofrom:lresult \\\[len: \[0-9\]+\\\]\\)" 2 "gimple" } } */
diff --git a/gcc/testsuite/gfortran.dg/goacc/loop-tree-1.f90 b/gcc/testsuite/gfortran.dg/goacc/loop-tree-1.f90
index 81bdc23..150f930 100644
--- a/gcc/testsuite/gfortran.dg/goacc/loop-tree-1.f90
+++ b/gcc/testsuite/gfortran.dg/goacc/loop-tree-1.f90
@@ -1,4 +1,4 @@
-! { dg-additional-options "-fdump-tree-original -std=f2008" } 
+! { dg-additional-options "-fdump-tree-original -fdump-tree-gimple -std=f2008" } 
 
 ! test for tree-dump-original and spaces-commas
 
@@ -44,3 +44,4 @@ end program test
 
 ! { dg-final { scan-tree-dump-times "private\\(m\\)" 1 "original" } } 
 ! { dg-final { scan-tree-dump-times "reduction\\(\\+:sum\\)" 1 "original" } } 
+! { dg-final { scan-tree-dump-times "map\\(tofrom:sum \\\[len: \[0-9\]+\\\]\\)" 1 "gimple" } }