AMDGPU: Emit note directive for HSA even if there are no functions

Reviewers: arsenm, echristo

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D16010

llvm-svn: 257488

3 files changed, 27 insertions, 7 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
index 89e7c1bd180..c1c34c37932 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
@@ -91,6 +91,25 @@ AMDGPUAsmPrinter::AMDGPUAsmPrinter(TargetMachine &TM,
                                    std::unique_ptr<MCStreamer> Streamer)
     : AsmPrinter(TM, std::move(Streamer)) {}
 
+void AMDGPUAsmPrinter::EmitStartOfAsmFile(Module &M) {
+  if (TM.getTargetTriple().getOS() != Triple::AMDHSA)
+    return;
+
+  // Need to construct an MCSubtargetInfo here in case we have no functions
+  // in the module.
+  std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
+        TM.getTargetTriple().str(), TM.getTargetCPU(),
+        TM.getTargetFeatureString()));
+
+  AMDGPUTargetStreamer *TS =
+      static_cast<AMDGPUTargetStreamer *>(OutStreamer->getTargetStreamer());
+
+  TS->EmitDirectiveHSACodeObjectVersion(1, 0);
+  AMDGPU::IsaVersion ISA = AMDGPU::getIsaVersion(STI->getFeatureBits());
+  TS->EmitDirectiveHSACodeObjectISA(ISA.Major, ISA.Minor, ISA.Stepping,
+                                    "AMD", "AMDGPU");
+}
+
 void AMDGPUAsmPrinter::EmitFunctionBodyStart() {
   const AMDGPUSubtarget &STM = MF->getSubtarget<AMDGPUSubtarget>();
   SIProgramInfo KernelInfo;
@@ -182,13 +201,6 @@ bool AMDGPUAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
     if (!STM.isAmdHsaOS()) {
       EmitProgramInfoSI(MF, KernelInfo);
     }
-    // Emit directives
-    AMDGPUTargetStreamer *TS =
-        static_cast<AMDGPUTargetStreamer *>(OutStreamer->getTargetStreamer());
-    TS->EmitDirectiveHSACodeObjectVersion(1, 0);
-    AMDGPU::IsaVersion ISA = STM.getIsaVersion();
-    TS->EmitDirectiveHSACodeObjectISA(ISA.Major, ISA.Minor, ISA.Stepping,
-                                      "AMD", "AMDGPU");
   } else {
     EmitProgramInfoR600(MF);
   }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.h b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.h
index 817cbfc0c0e..99d4091670f 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.h
@@ -103,6 +103,8 @@ public:
 
   void EmitGlobalVariable(const GlobalVariable *GV) override;
 
+  void EmitStartOfAsmFile(Module &M) override;
+
   bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                        unsigned AsmVariant, const char *ExtraCode,
                        raw_ostream &O) override;
diff --git a/llvm/test/CodeGen/AMDGPU/hsa-note-no-func.ll b/llvm/test/CodeGen/AMDGPU/hsa-note-no-func.ll
new file mode 100644
index 00000000000..0e4662231b4
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/hsa-note-no-func.ll
@@ -0,0 +1,6 @@
+; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=kaveri | FileCheck --check-prefix=HSA --check-prefix=HSA-CI %s
+; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=carrizo | FileCheck --check-prefix=HSA --check-prefix=HSA-VI %s
+
+; HSA: .hsa_code_object_version 1,0
+; HSA-CI: .hsa_code_object_isa 7,0,0,"AMD","AMDGPU"
+; HSA-VI: .hsa_code_object_isa 8,0,1,"AMD","AMDGPU"