[SYCL] Add sycl-enable-bfloat16-conversion compilation flag

This flag defines __SYCL_ENABLE_BF16_CONVERSION__ macro that
can be used to specify whether BF16 conversion feature is supported.
This macro is being defined for both host and device compilation.

Signed-off-by: Dmitry Sidorov <[email protected]>

Author: MrSidims

clang/include/clang/Basic/LangOptions.def

@@ -269,6 +269,9 @@ LANGOPT(
     "get/operator[], get_id/operator[] and get_global_id/get_global_linear_id "
     "in SYCL class id, iterm and nd_iterm")
 LANGOPT(SYCLDisableRangeRounding, 1, 0, "Disable parallel for range rounding")
+LANGOPT(
+    SYCLEnableBF16Conversion, 1, 0,
+    "Enable generation of BFloat16 conversion instructions")
 
 LANGOPT(HIPUseNewLaunchAPI, 1, 0, "Use new kernel launching API for HIP")
 

clang/include/clang/Driver/Options.td

@@ -2689,6 +2689,10 @@ def fno_sycl_link_spirv : Flag<["-"], "fno-sycl-link-spirv">,
   "when discovered in user specified objects and archives.">;
 def fsyntax_only : Flag<["-"], "fsyntax-only">,
   Flags<[NoXarchOption,CoreOption,CC1Option,FC1Option]>, Group<Action_Group>;
+defm sycl_enable_bfloat16_conversion: BoolFOption<"sycl-enable-bfloat16-conversion",
+  LangOpts<"SYCLEnableBF16Conversion">, DefaultFalse,
+  PosFlag<SetTrue, [], "Enable">, NegFlag<SetFalse, [], "Do not enable">,
+  BothFlags<[CC1Option, CoreOption], " BFloat16 conversion extension">>;
 def ftabstop_EQ : Joined<["-"], "ftabstop=">, Group<f_Group>;
 def ftemplate_depth_EQ : Joined<["-"], "ftemplate-depth=">, Group<f_Group>;
 def ftemplate_depth_ : Joined<["-"], "ftemplate-depth-">, Group<f_Group>;

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4705,6 +4705,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                                  options::OPT_fno_sycl_id_queries_fit_in_int))
       A->render(Args, CmdArgs);
 
+    // Set options for both host and device so we can manipulate host logic
+    // in case if bfloat16 conversion is supported
+    if (Arg *A = Args.getLastArg(options::OPT_fsycl_enable_bfloat16_conversion,
+                                 options::OPT_fsycl_enable_bfloat16_conversion))
+      A->render(Args, CmdArgs);
+
     if (SYCLStdArg) {
       SYCLStdArg->render(Args, CmdArgs);
       CmdArgs.push_back("-fsycl-std-layout-kernel-params");

clang/lib/Frontend/InitPreprocessor.cpp

@@ -495,6 +495,9 @@ static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
     // flag is used.
     if (LangOpts.SYCLDisableRangeRounding)
       Builder.defineMacro("__SYCL_DISABLE_PARALLEL_FOR_RANGE_ROUNDING__");
+
+    if (LangOpts.SYCLEnableBF16Conversion)
+      Builder.defineMacro("__SYCL_ENABLE_BF16_CONVERSION__");
   }
 
   if (LangOpts.DeclareSPIRVBuiltins) {

clang/test/Driver/sycl.c

@@ -39,6 +39,7 @@
 // RUN: %clang_cl -### -fsycl-device-only %s 2>&1 | FileCheck %s --check-prefix=DEFAULT
 // RUN: %clangxx -### -fsycl-device-only -fno-sycl-unnamed-lambda %s 2>&1 | FileCheck %s --check-prefix=CHECK-NOT-LAMBDA
 // RUN: %clang_cl -### -fsycl-device-only -fno-sycl-unnamed-lambda %s 2>&1 | FileCheck %s --check-prefix=CHECK-NOT-LAMBDA
+// RUN: %clangxx -### -fsycl-device-only -fsycl-enable-bfloat16-conversion %s 2>&1 | FileCheck %s --check-prefix=CHECK-BFLOAT16-CONV
 
 // DEFAULT: "-triple" "spir64-unknown-{{.*}}-sycldevice"{{.*}} "-fsycl-is-device"{{.*}} "-sycl-std=2020"{{.*}} "-emit-llvm-bc"
 // DEFAULT: "-internal-isystem" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"
@@ -53,6 +54,7 @@
 // COMBINED: "-triple" "spir64-unknown-{{.*}}-sycldevice"{{.*}} "-fsycl-is-device"{{.*}} "-emit-llvm-bc"
 // TEXTUAL: "-triple" "spir64-unknown-{{.*}}-sycldevice{{.*}}" "-fsycl-is-device"{{.*}} "-emit-llvm"
 // CHECK-NOT-LAMBDA: "-fno-sycl-unnamed-lambda"
+// CHECK-BFLOAT16-CONV: "-fsycl-enable-bfloat16-conversion"
 
 /// -fsycl-device-only triple checks
 // RUN: %clang -fsycl-device-only -target x86_64-unknown-linux-gnu -### %s 2>&1 \

clang/test/Preprocessor/sycl-macro.cpp

@@ -10,6 +10,19 @@
 // RUN: %clang_cc1 -fno-sycl-id-queries-fit-in-int %s -E -dM | FileCheck \
 // RUN: --check-prefix=CHECK-NO-SYCL_FIT_IN_INT %s
 
+// RUN: %clang_cc1 %s -fsycl-is-device -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV-DISABLED %s
+// RUN: %clang_cc1 %s -fsycl-is-host -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV-DISABLED %s
+// RUN: %clang_cc1 -fsycl-is-device -fsycl-enable-bfloat16-conversion -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV %s
+// RUN: %clang_cc1 -fsycl-is-host -fsycl-enable-bfloat16-conversion -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV %s
+// RUN: %clang_cc1 -fsycl-is-device -fno-sycl-enable-bfloat16-conversion -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV-DISABLED %s
+// RUN: %clang_cc1 -fsycl-is-host -fno-sycl-enable-bfloat16-conversion -E -dM | FileCheck \
+// RUN: --check-prefix=CHECK-SYCL-BFLOAT16-CONV-DISABLED %s
+
 // CHECK-NOT:#define __SYCL_DEVICE_ONLY__ 1
 // CHECK-NOT:#define SYCL_EXTERNAL
 // CHECK-NOT:#define CL_SYCL_LANGUAGE_VERSION 121
@@ -30,3 +43,6 @@
 
 // CHECK-NO-SYCL_FIT_IN_INT-NOT:#define __SYCL_ID_QUERIES_FIT_IN_INT__ 1
 // CHECK-SYCL-ID:#define __SYCL_ID_QUERIES_FIT_IN_INT__ 1
+
+// CHECK-SYCL-BFLOAT16-CONV:#define __SYCL_ENABLE_BF16_CONVERSION__ 1
+// CHECK-SYCL-BFLOAT16-CONV-DISABLED-NOT:#define __SYCL_ENABLE_BF16_CONVERSION__ 1