[HIP][Clang][Preprocessor] Add Preprocessor support for hipstdpar

This patch adds the Driver changes needed for enabling HIP parallel algorithm offload on AMDGPU targets. This change merely adds two macros to inform user space if we are compiling in `hipstdpar` mode and, respectively, if the optional allocation interposition mode has been requested, as well as associated minimal tests. The macros can be used by the runtime implementation of offload to drive conditional compilation, and are only defined if the HIP language has been enabled.

Reviewed by: yaxunl

Differential Revision: https://reviews.llvm.org/D155826

clang/lib/Frontend/InitPreprocessor.cpp

@@ -585,6 +585,11 @@ static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
     Builder.defineMacro("__HIP_MEMORY_SCOPE_WORKGROUP", "3");
     Builder.defineMacro("__HIP_MEMORY_SCOPE_AGENT", "4");
     Builder.defineMacro("__HIP_MEMORY_SCOPE_SYSTEM", "5");
+    if (LangOpts.HIPStdPar) {
+      Builder.defineMacro("__HIPSTDPAR__");
+      if (LangOpts.HIPStdParInterposeAlloc)
+        Builder.defineMacro("__HIPSTDPAR_INTERPOSE_ALLOC__");
+    }
     if (LangOpts.CUDAIsDevice) {
       Builder.defineMacro("__HIP_DEVICE_COMPILE__");
       if (!TI.hasHIPImageSupport()) {

clang/test/Preprocessor/predefined-macros.c

@@ -290,3 +290,20 @@
 // RUN:   -fcuda-is-device -fgpu-default-stream=per-thread \
 // RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-PTH
 // CHECK-PTH: #define HIP_API_PER_THREAD_DEFAULT_STREAM 1
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hip --hipstdpar -triple x86_64-unknown-linux-gnu \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-HIPSTDPAR
+// CHECK-HIPSTDPAR: #define __HIPSTDPAR__ 1
+// CHECK-HIPSTDPAR-NOT: #define __HIPSTDPAR_INTERPOSE_ALLOC__ 1
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hip --hipstdpar --hipstdpar-interpose-alloc \
+// RUN:  -triple x86_64-unknown-linux-gnu | FileCheck -match-full-lines %s \
+// RUN:  --check-prefix=CHECK-HIPSTDPAR-INTERPOSE
+// CHECK-HIPSTDPAR-INTERPOSE: #define __HIPSTDPAR_INTERPOSE_ALLOC__ 1
+// CHECK-HIPSTDPAR-INTERPOSE: #define __HIPSTDPAR__ 1
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hip --hipstdpar --hipstdpar-interpose-alloc \
+// RUN:  -triple amdgcn-amd-amdhsa -fcuda-is-device | FileCheck -match-full-lines \
+// RUN:  %s --check-prefix=CHECK-HIPSTDPAR-INTERPOSE-DEV-NEG
+// CHECK-HIPSTDPAR-INTERPOSE-DEV-NEG: #define __HIPSTDPAR__ 1
+// CHECK-HIPSTDPAR-INTERPOSE-DEV-NEG-NOT: #define __HIPSTDPAR_INTERPOSE_ALLOC__ 1