[OpenMP] Replace nvvm.annotation usage with kernel calling conventions (#122320)

Specifying a kernel with the `ptx_kernel` or `amdgpu_kernel` calling
convention is a more idiomatic and compile-time performant than using
the `nvvm.annoation !"kernel"` metadata.

Transition OMPIRBuilder to use calling conventions for PTX kernels and
no longer emit `nvvm.annoation`. Update OpenMPOpt to work with kernels
specified via calling convention as well as metadata. Update OpenMP
tests to use the calling conventions.

1 files changed, 0 insertions, 20 deletions

diff --git a/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp b/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
index 4261615..64fef02c 100644
--- a/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
+++ b/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
@@ -7622,26 +7622,6 @@ TEST_F(OpenMPIRBuilderTest, createGPUOffloadEntry) {
                                 /* Size = */ 0,
                                 /* Flags = */ 0, GlobalValue::WeakAnyLinkage);
 
-  // Check nvvm.annotations only created for GPU kernels
-  NamedMDNode *MD = M->getNamedMetadata("nvvm.annotations");
-  EXPECT_NE(MD, nullptr);
-  EXPECT_EQ(MD->getNumOperands(), 1u);
-
-  MDNode *Annotations = MD->getOperand(0);
-  EXPECT_EQ(Annotations->getNumOperands(), 3u);
-
-  Constant *ConstVal =
-      dyn_cast<ConstantAsMetadata>(Annotations->getOperand(0))->getValue();
-  EXPECT_TRUE(isa<Function>(Fn));
-  EXPECT_EQ(ConstVal, cast<Function>(Fn));
-
-  EXPECT_TRUE(Annotations->getOperand(1).equalsStr("kernel"));
-
-  EXPECT_TRUE(mdconst::hasa<ConstantInt>(Annotations->getOperand(2)));
-  APInt IntVal =
-      mdconst::extract<ConstantInt>(Annotations->getOperand(2))->getValue();
-  EXPECT_EQ(IntVal, 1);
-
   // Check kernel attributes
   EXPECT_TRUE(Fn->hasFnAttribute("kernel"));
   EXPECT_TRUE(Fn->hasFnAttribute(Attribute::MustProgress));