Support FPGA function !spirv.Decoration metadata (#1727)

Supporting the new FPGA kernel attribute pipelined needs the translator
to handle !spirv.Decoration metadata on functions as well as on global
variables.  If the MD is found on the function, call the existing
translation of metadata.

Author: mendell27

lib/SPIRV/SPIRVWriter.cpp

@@ -974,6 +974,8 @@ void LLVMToSPIRVBase::transVectorComputeMetadata(Function *F) {
   }
 }
 
+static void transMetadataDecorations(Metadata *MD, SPIRVEntry *Target);
+
 void LLVMToSPIRVBase::transFPGAFunctionMetadata(SPIRVFunction *BF,
                                                 Function *F) {
   if (MDNode *StallEnable = F->getMetadata(kSPIR2MD::StallEnable)) {
@@ -1022,6 +1024,10 @@ void LLVMToSPIRVBase::transFPGAFunctionMetadata(SPIRVFunction *BF,
       BF->addDecorate(new SPIRVDecoratePipelineEnableINTEL(BF, !Disable));
     }
   }
+
+  // In addition, process the decorations on the function
+  if (auto *FDecoMD = F->getMetadata(SPIRV_MD_DECORATIONS))
+    transMetadataDecorations(FDecoMD, BF);
 }
 
 SPIRVValue *LLVMToSPIRVBase::transConstantUse(Constant *C) {

test/extensions/INTEL/SPV_INTEL_kernel_attributes/spirv_fpga_function_decorations.ll

@@ -0,0 +1,45 @@
+; Check that !spirv.Decorations are handled on FPGA functions as well as global variables
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc --spirv-ext=+SPV_INTEL_fpga_invocation_pipelining_attributes -spirv-text -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: llvm-spirv --spirv-ext=+SPV_INTEL_fpga_invocation_pipelining_attributes %t.bc -o %t.spv
+; RUN: llvm-spirv --spirv-ext=+SPV_INTEL_fpga_invocation_pipelining_attributes -r -emit-opaque-pointers %t.spv --spirv-target-env=SPV-IR -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-SPV-IR
+; RUN: llvm-spirv -r --spirv-ext=+SPV_INTEL_fpga_invocation_pipelining_attributes -emit-opaque-pointers %t.spv --spirv-target-env=SPV-IR -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir"
+
+; Function Attrs: convergent nounwind
+define spir_kernel void @k(float %a, float %b, float %c) #0 !kernel_arg_addr_space !4 !kernel_arg_access_qual !5 !kernel_arg_type !6 !kernel_arg_type_qual !7 !kernel_arg_base_type !6 !spirv.Decorations !9 {
+entry:
+  ret void
+}
+
+; CHECK-SPIRV: Decorate [[PId1:[0-9]+]] PipelineEnableINTEL 1
+; CHECK-SPIRV: Decorate [[PId1]] InitiationIntervalINTEL 2
+
+!llvm.module.flags = !{!0}
+!opencl.ocl.version = !{!1}
+!opencl.spir.version = !{!2}
+!llvm.ident = !{!3}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 0}
+!2 = !{i32 1, i32 2}
+!3 = !{!"clang version 14.0.0"}
+!4 = !{i32 0, i32 0, i32 0}
+!5 = !{!"none", !"none", !"none"}
+!6 = !{!"float", !"float", !"float"}
+!7 = !{!"", !"", !""}
+!8 = !{i32 19}
+!9 = !{!10, !11}
+!10 = !{i32 5919, i32 1}
+!11 = !{i32 5917, i32 2}
+
+; CHECK-SPV-IR: define spir_kernel void @k(float %a, float %b, float %c) {{.*}} !initiation_interval ![[II:[0-9]+]] !disable_loop_pipelining ![[DISABLE_LOOP_PIPELINING:[0-9]+]] {
+; CHECK-SPV-IR-DAG: ![[II]] = !{i32 2}
+; CHECK-SPV-IR-DAG: ![[DISABLE_LOOP_PIPELINING]] = !{i32 0}
+
+; CHECK-LLVM-NOT: define spir_kernel void @k(float %a, float %b, float %c) {{.*}} !spirv.Decorations ![[DecoListId:[0-9]+]] {
+; CHECK-LLVM: define spir_kernel void @k(float %a, float %b, float %c) {{.*}} {