[ESIMD] Disable non-critical messages from VC backend (disable-finalizer-msg) (#4918)

1. Add doc for the existing environment variable SYCL_RT_WARNING_LEVEL.
2. Add -disable-finalizer-msg to vc-codegen to disable warnings/hints from vc-codegen
about spilling some registers to memory, which are performance hints and often not wanted
in std output by default.

Signed-off-by: Vyacheslav N Klochkov <[email protected]>

Author: v-klochkov

sycl/doc/EnvironmentVariables.md

@@ -21,6 +21,7 @@ compiler and runtime.
 | `SYCL_CACHE_MIN_DEVICE_IMAGE_SIZE` | Positive integer | Minimum size of device code image in bytes which is reasonable to cache on disk because disk access operation may take more time than do JIT compilation for it. Default value is 0 to cache all images. |
 | `SYCL_CACHE_MAX_DEVICE_IMAGE_SIZE` | Positive integer | Maximum size of device image in bytes which is cached. Too big kernels may overload disk too fast. Default value is 1 GB. |
 | `SYCL_ENABLE_DEFAULT_CONTEXTS` | '1' or '0' | Enable ('1') or disable ('0') creation of default platform contexts in SYCL runtime. The default context for each platform contains all devices in the platform. Refer to [Platform Default Contexts](extensions/supported/sycl_ext_oneapi_default_context.asciidoc) extension to learn more. Enabled by default on Linux and disabled on Windows. |
+| `SYCL_RT_WARNING_LEVEL` | Positive integer | The higher warning level is used the more warnings and performance hints the runtime library may print. Default value is '0', which means no warning/hint messages from the runtime library are allowed. The value '1' enables performance warnings from device runtime/codegen. The values greater than 1 are reserved for future use. |
 | `SYCL_USM_HOSTPTR_IMPORT` | Integer | Enable by specifying non-zero value. Buffers created with a host pointer will result in host data promotion to USM, improving data transfer performance. To use this feature, also set SYCL_HOST_UNIFIED_MEMORY=1. |
 
 `(*) Note: Any means this environment variable is effective when set to any non-null value.`

sycl/source/detail/program_manager/program_manager.cpp

@@ -403,6 +403,10 @@ static void appendCompileOptionsFromImage(std::string &CompileOpts,
     if (!CompileOpts.empty())
       CompileOpts += " ";
     CompileOpts += "-vc-codegen";
+    // Allow warning and performance hints from vc/finalizer if the RT warning
+    // level is at least 1.
+    if (detail::SYCLConfig<detail::SYCL_RT_WARNING_LEVEL>::get() == 0)
+      CompileOpts += " -disable-finalizer-msg";
   }
 }
 

sycl/unittests/misc/KernelBuildOptions.cpp

@@ -243,15 +243,14 @@ TEST(KernelBuildOptions, KernelBundleBasic) {
   sycl::kernel_bundle KernelBundle =
       sycl::get_kernel_bundle<sycl::bundle_state::input>(Ctx, {Dev});
   auto ExecBundle = sycl::build(KernelBundle);
-  EXPECT_EQ(BuildOpts, "-compile-img -vc-codegen -link-img");
+  EXPECT_EQ(BuildOpts,
+            "-compile-img -vc-codegen -disable-finalizer-msg -link-img");
 
   auto ObjBundle = sycl::compile(KernelBundle, KernelBundle.get_devices());
-  // TODO: uncomment when image options are passed to BE
-  // EXPECT_EQ(BuildOpts, "-compile-img -vc-codegen");
+  EXPECT_EQ(BuildOpts, "-compile-img -vc-codegen -disable-finalizer-msg");
 
   auto LinkBundle = sycl::link(ObjBundle, ObjBundle.get_devices());
-  // TODO: uncomment when image options are passed to BE
-  // EXPECT_EQ(BuildOpts, "-link-img -vc-codegen");
+  EXPECT_EQ(BuildOpts, "-link-img");
 }
 
 TEST(KernelBuildOptions, Program) {