[OpenMP][OMPIRBuilder] Use runtime CC for runtime calls (#168608)

Some targets have a specific calling convention that should be used for
generated calls to runtime functions.

Pass that down and use it.

Signed-off-by: Nick Sarnie <[email protected]>

Author: sarnex

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -1040,6 +1040,7 @@ CGOpenMPRuntime::CGOpenMPRuntime(CodeGenModule &CGM)
       hasRequiresUnifiedSharedMemory(), /*HasRequiresDynamicAllocators*/ false);
   Config.setDefaultTargetAS(
       CGM.getContext().getTargetInfo().getTargetAddressSpace(LangAS::Default));
+  Config.setRuntimeCC(CGM.getRuntimeCC());
 
   OMPBuilder.setConfig(Config);
   OMPBuilder.initialize();

clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp

@@ -871,6 +871,8 @@ CGOpenMPRuntimeGPU::CGOpenMPRuntimeGPU(CodeGenModule &CGM)
       hasRequiresUnifiedSharedMemory(), /*HasRequiresDynamicAllocators*/ false);
   Config.setDefaultTargetAS(
       CGM.getContext().getTargetInfo().getTargetAddressSpace(LangAS::Default));
+  Config.setRuntimeCC(CGM.getRuntimeCC());
+
   OMPBuilder.setConfig(Config);
 
   if (!CGM.getLangOpts().OpenMPIsTargetDevice)

clang/test/OpenMP/spirv_target_codegen_basic.cpp

@@ -9,9 +9,10 @@
 // CHECK: @"_gomp_critical_user_$var" = common addrspace(1) global [8 x i32] zeroinitializer, align 8
 
 // CHECK: define weak_odr protected spir_kernel void @__omp_offloading_{{.*}}
-
+// CHECK: call spir_func addrspace(9) i32 @__kmpc_target_init(
 // CHECK: call spir_func addrspace(9) void @__kmpc_critical(ptr addrspace(4) addrspacecast (ptr addrspace(1) @{{.*}} to ptr addrspace(4)), i32 %{{.*}}, ptr addrspace(4) addrspacecast (ptr addrspace(1) @"_gomp_critical_user_$var" to ptr addrspace(4)))
 // CHECK: call spir_func addrspace(9) void @__kmpc_end_critical(ptr addrspace(4) addrspacecast (ptr addrspace(1) @{{.*}} to ptr addrspace(4)), i32 %{{.*}}, ptr addrspace(4) addrspacecast (ptr addrspace(1) @"_gomp_critical_user_$var" to ptr addrspace(4)))
+// CHECK: call spir_func addrspace(9) void @__kmpc_target_deinit(
 
 int main() {
   int ret = 0;

llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h

@@ -17,6 +17,7 @@
 #include "llvm/Frontend/Atomic/Atomic.h"
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
 #include "llvm/Frontend/OpenMP/OMPGridValues.h"
+#include "llvm/IR/CallingConv.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Module.h"
@@ -138,6 +139,8 @@ class OpenMPIRBuilderConfig {
   // Default address space for the target.
   unsigned DefaultTargetAS = 0;
 
+  CallingConv::ID RuntimeCC = llvm::CallingConv::C;
+
   LLVM_ABI OpenMPIRBuilderConfig();
   LLVM_ABI OpenMPIRBuilderConfig(bool IsTargetDevice, bool IsGPU,
                                  bool OpenMPOffloadMandatory,
@@ -170,6 +173,8 @@ class OpenMPIRBuilderConfig {
 
   unsigned getDefaultTargetAS() const { return DefaultTargetAS; }
 
+  CallingConv::ID getRuntimeCC() const { return RuntimeCC; }
+
   bool hasRequiresFlags() const { return RequiresFlags; }
   LLVM_ABI bool hasRequiresReverseOffload() const;
   LLVM_ABI bool hasRequiresUnifiedAddress() const;
@@ -208,6 +213,7 @@ class OpenMPIRBuilderConfig {
   void setSeparator(StringRef S) { Separator = S; }
   void setGridValue(omp::GV G) { GridValue = G; }
   void setDefaultTargetAS(unsigned AS) { DefaultTargetAS = AS; }
+  void setRuntimeCC(CallingConv::ID CC) { RuntimeCC = CC; }
 
   LLVM_ABI void setHasRequiresReverseOffload(bool Value);
   LLVM_ABI void setHasRequiresUnifiedAddress(bool Value);
@@ -2132,6 +2138,10 @@ class OpenMPIRBuilder {
 
   LLVM_ABI Function *getOrCreateRuntimeFunctionPtr(omp::RuntimeFunction FnID);
 
+  CallInst *createRuntimeFunctionCall(FunctionCallee Callee,
+                                      ArrayRef<Value *> Args,
+                                      StringRef Name = "");
+
   /// Return the (LLVM-IR) string describing the source location \p LocStr.
   LLVM_ABI Constant *getOrCreateSrcLocStr(StringRef LocStr,
                                           uint32_t &SrcLocStrSize);