1 files changed, 109 insertions, 0 deletions
diff --git a/ruy/context.cc b/ruy/context.cc
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+++ b/ruy/context.cc
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+/* Copyright 2019 Google LLC. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#include "ruy/context.h"
+
+#include "ruy/check_macros.h"
+#include "ruy/detect_arm.h"
+#include "ruy/detect_x86.h"
+#include "ruy/have_built_path_for.h"
+#include "ruy/platform.h"
+
+namespace ruy {
+
+void Context::SetRuntimeEnabledPaths(Path paths) {
+  runtime_enabled_paths_ = paths;
+}
+
+Path Context::GetRuntimeEnabledPaths() {
+  // This function should always return the same value on a given machine.
+  // When runtime_enabled_paths_ has its initial value kNone, it performs
+  // some platform detection to resolve it to specific Path values.
+
+  // Fast path: already resolved.
+  if (runtime_enabled_paths_ != Path::kNone) {
+    return runtime_enabled_paths_;
+  }
+
+  // Need to resolve now. Start by considering all paths enabled.
+  runtime_enabled_paths_ = kAllPaths;
+
+  // This mechanism is intended to be used for testing and benchmarking. For
+  // example, one can set RUY_FORCE_DISABLE_PATHS to Path::kAvx512 in order to
+  // evaluate AVX2 performance on an AVX-512 machine.
+#ifdef RUY_FORCE_DISABLE_PATHS
+  runtime_enabled_paths_ = runtime_enabled_paths_ & ~(RUY_FORCE_DISABLE_PATHS);
+#endif
+
+#if RUY_PLATFORM(ARM)
+  // Now selectively disable paths that aren't supported on this machine.
+  if ((runtime_enabled_paths_ & Path::kNeonDotprod) != Path::kNone) {
+    if (!DetectDotprod()) {
+      runtime_enabled_paths_ = runtime_enabled_paths_ & ~Path::kNeonDotprod;
+      // Sanity check.
+      RUY_DCHECK((runtime_enabled_paths_ & Path::kNeonDotprod) == Path::kNone);
+    }
+  }
+#endif  // RUY_PLATFORM(ARM)
+
+#if RUY_PLATFORM(X86)
+  // TODO(b/147376783): SSE 4.2 and AVX-VNNI support is incomplete /
+  // placeholder. Optimization is not finished. In particular the dimensions of
+  // the kernel blocks can be changed as desired.
+  //
+  if ((runtime_enabled_paths_ & Path::kSse42) != Path::kNone) {
+    if (!(HaveBuiltPathForSse42() && DetectCpuSse42())) {
+      runtime_enabled_paths_ = runtime_enabled_paths_ & ~Path::kSse42;
+      // Sanity check.
+      RUY_DCHECK((runtime_enabled_paths_ & Path::kSse42) == Path::kNone);
+    }
+  }
+
+  if ((runtime_enabled_paths_ & Path::kAvx2) != Path::kNone) {
+    if (!(HaveBuiltPathForAvx2() && DetectCpuAvx2())) {
+      runtime_enabled_paths_ = runtime_enabled_paths_ & ~Path::kAvx2;
+      // Sanity check.
+      RUY_DCHECK((runtime_enabled_paths_ & Path::kAvx2) == Path::kNone);
+    }
+  }
+
+  if ((runtime_enabled_paths_ & Path::kAvx512) != Path::kNone) {
+    if (!(HaveBuiltPathForAvx512() && DetectCpuAvx512())) {
+      runtime_enabled_paths_ = runtime_enabled_paths_ & ~Path::kAvx512;
+      // Sanity check.
+      RUY_DCHECK((runtime_enabled_paths_ & Path::kAvx512) == Path::kNone);
+    }
+  }
+
+  // TODO(b/147376783): SSE 4.2 and AVX-VNNI support is incomplete /
+  // placeholder. Optimization is not finished. In particular the dimensions of
+  // the kernel blocks can be changed as desired.
+  //
+  if ((runtime_enabled_paths_ & Path::kAvxVnni) != Path::kNone) {
+    if (!(HaveBuiltPathForAvxVnni() && DetectCpuAvxVnni())) {
+      runtime_enabled_paths_ = runtime_enabled_paths_ & ~Path::kAvxVnni;
+      // Sanity check.
+      RUY_DCHECK((runtime_enabled_paths_ & Path::kAvxVnni) == Path::kNone);
+    }
+  }
+#endif  // RUY_PLATFORM(X86)
+
+  // Sanity check. We can't possibly have disabled all paths, as some paths
+  // are universally available (kReference, kStandardCpp).
+  RUY_DCHECK_NE(runtime_enabled_paths_, Path::kNone);
+  return runtime_enabled_paths_;
+}
+
+}  // namespace ruy