Hi!
In OpenMP 5.0, although the simd loop iteration vars are still predetermined
linear (for non-collapsed loops or collapse(1)) or lastprivate (collapse>1),
one can explicitly make the iteration variable private or lastprivate;
especially the former is useful to make it clear nothing needs to be
propagated to the original list item.
Tested on x86_64-linux, committed to gomp-5_0-branch.
2018-06-04 Jakub Jelinek <ja...@redhat.com>
* gimplify.c (omp_is_private): Allow simd iterator to be lastprivate
or private. Fix up diagnostics if linear is used on collapse>1 simd
iterator.
* gcc.dg/gomp/simd-1.c: New test.
* g++.dg/gomp/simd-2.C: New test.
* testsuite/libgomp.c-c++-common/simd-1.c: New test.
--- gcc/gimplify.c.jj 2018-05-31 17:16:02.925643457 +0200
+++ gcc/gimplify.c 2018-06-04 12:40:32.232748770 +0200
@@ -7463,18 +7463,9 @@ omp_is_private (struct gimplify_omp_ctx
else if ((n->value & GOVD_REDUCTION) != 0)
error ("iteration variable %qE should not be reduction",
DECL_NAME (decl));
- else if (simd == 0 && (n->value & GOVD_LINEAR) != 0)
+ else if (simd != 1 && (n->value & GOVD_LINEAR) != 0)
error ("iteration variable %qE should not be linear",
DECL_NAME (decl));
- else if (simd == 1 && (n->value & GOVD_LASTPRIVATE) != 0)
- error ("iteration variable %qE should not be lastprivate",
- DECL_NAME (decl));
- else if (simd && (n->value & GOVD_PRIVATE) != 0)
- error ("iteration variable %qE should not be private",
- DECL_NAME (decl));
- else if (simd == 2 && (n->value & GOVD_LINEAR) != 0)
- error ("iteration variable %qE is predetermined linear",
- DECL_NAME (decl));
}
return (ctx == gimplify_omp_ctxp
|| (ctx->region_type == ORT_COMBINED_PARALLEL
--- gcc/testsuite/gcc.dg/gomp/simd-1.c.jj 2018-06-04 14:32:12.406269289
+0200
+++ gcc/testsuite/gcc.dg/gomp/simd-1.c 2018-06-04 14:13:31.279028667 +0200
@@ -0,0 +1,21 @@
+int a[32], b[32];
+
+void
+foo (void)
+{
+ int i, j;
+ #pragma omp simd linear(i, j) collapse(2) /* { dg-error "iteration
variable 'i' should not be linear" } */
+ for (i = 0; i < 32; ++i) /* { dg-error "iteration
variable 'j' should not be linear" "" { target *-*-* } .-1 } */
+ for (j = 0; j < 32; ++j)
+ a[i] += b[j];
+}
+
+void
+bar (void)
+{
+ static int i, j;
+ #pragma omp for simd linear(i, j) collapse(2) /* { dg-error
"iteration variable 'i' should not be linear" } */
+ for (i = 0; i < 32; ++i) /* { dg-error "iteration
variable 'j' should not be linear" "" { target *-*-* } .-1 } */
+ for (j = 0; j < 32; ++j)
+ a[i] += b[j];
+}
--- gcc/testsuite/g++.dg/gomp/simd-2.C.jj 2018-06-04 14:32:28.938287583
+0200
+++ gcc/testsuite/g++.dg/gomp/simd-2.C 2018-06-04 14:37:43.931636150 +0200
@@ -0,0 +1,21 @@
+int a[32], b[32];
+
+void
+foo (void)
+{
+ int i, j;
+ #pragma omp simd linear(i, j) collapse(2) // { dg-error "iteration
variable 'i' should not be linear" }
+ for (i = 0; i < 32; ++i) // { dg-error "iteration
variable 'j' should not be linear" "" { target *-*-* } .-1 }
+ for (j = 0; j < 32; ++j)
+ a[i] += b[j];
+}
+
+void
+bar (void)
+{
+ static int i, j;
+ #pragma omp for simd linear(i, j) collapse(2) // { dg-error
"iteration variable 'i' should not be linear" "" { target *-*-* } .+1 }
+ for (i = 0; i < 32; ++i) // { dg-error "iteration
variable 'j' should not be linear" }
+ for (j = 0; j < 32; ++j)
+ a[i] += b[j];
+}
--- libgomp/testsuite/libgomp.c-c++-common/simd-1.c.jj 2018-06-04
14:18:27.803356796 +0200
+++ libgomp/testsuite/libgomp.c-c++-common/simd-1.c 2018-06-04
14:19:02.968395710 +0200
@@ -0,0 +1,71 @@
+// { dg-do run }
+// { dg-additional-options "-msse2" { target sse2_runtime } }
+// { dg-additional-options "-mavx" { target avx_runtime } }
+
+#define N 1024
+int a[N], b[N];
+
+int
+f1 (void)
+{
+ int i;
+ #pragma omp simd private (i)
+ for (i = 0; i < N; i++)
+ a[i] = b[i] * 2;
+ #pragma omp simd lastprivate (i)
+ for (i = 0; i < N; i++)
+ a[i] += b[i] * 2;
+ return i;
+}
+
+int
+f2 (void)
+{
+ int i, j;
+ #pragma omp simd private (i), collapse (2), lastprivate (j)
+ for (i = 0; i < 32; i++)
+ for (j = 0; j < 32; ++j)
+ a[i * 32 + j] += b[i * 32 + j] * 2;
+ return j;
+}
+
+int
+f3 (void)
+{
+ static int i;
+ #pragma omp for simd private (i)
+ for (i = 0; i < N; ++i)
+ a[i] = b[i] * 2;
+ #pragma omp for simd lastprivate (i)
+ for (i = 0; i < N; ++i)
+ a[i] += b[i] * 2;
+ return i;
+}
+
+int
+f4 (void)
+{
+ static int i, j;
+ #pragma omp for simd private (i)collapse (2)lastprivate (j)
+ for (i = 0; i < 32; ++i)
+ for (j = 0; j < 32; j++)
+ a[i * 32 + j] += b[i * 32 + j] * 2;
+ return j;
+}
+
+int
+main ()
+{
+ int i;
+ for (i = 0; i < N; ++i)
+ a[i] = b[i] = i;
+ if (f1 () != 1024 || f2 () != 32)
+ __builtin_abort ();
+ #pragma omp parallel num_threads(4)
+ if (f3 () != 1024 || f4 () != 32)
+ __builtin_abort ();
+ for (i = 0; i < N; ++i)
+ if (a[i] != 6 * i || b[i] != i)
+ __builtin_abort ();
+ return 0;
+}
Jakub
