AMDGPU: Add runtime metadata for printf

[yaxunl]

superseded by D23424

[yaxunl]

superseded by D23424

lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp

       }
     }
   }
+
+  if (auto MD = M.getNamedMetadata("llvm.printf.fmts")) {
+    for (unsigned I = 0; I < MD->getNumOperands(); ++I) {
+      auto Node = MD->getOperand(I);
+      if (Node->getNumOperands() > 0)
+        emitRuntimeMDStringValue(*OutStreamer, RuntimeMD::KeyPrintfInfo,
+            cast<MDString>(Node->getOperand(0))->getString());
+    }
+  }
 }
 
 static std::string getOCLTypeName(Type *Ty, bool Signed) {

lib/Target/AMDGPU/AMDGPURuntimeMetadata.h

     KeyFlatWorkGroupSizeLimits  = 29, // Flat work group size limits
     KeyMaxWorkGroupSize         = 30, // Maximum work group size
     KeyNoPartialWorkGroups      = 31, // No partial work groups
+    KeyPrintfInfo               = 32, // Prinf function call information
   };
 
   enum Language : uint8_t {

test/CodeGen/AMDGPU/runtime-metadata.ll

 ; CHECK-NEXT: .byte 0
 ; CHECK-NEXT: .byte 3
 ; CHECK-NEXT: .short  200
+; CHECK-NEXT: .byte     32
+; CHECK-NEXT: .long     10
+; CHECK-NEXT: .ascii    "1:1:4:%d\\n"
+; CHECK-NEXT: .byte     32
+; CHECK-NEXT: .long     10
+; CHECK-NEXT: .ascii    "2:1:8:%g\\n"
 
 ; CHECK-LABEL:{{^}}test_char:
 ; CHECK: .section        .AMDGPU.runtime_metadata

   ret void
 }
 
+!llvm.printf.fmts = !{!100, !101}
+
 !1 = !{i32 0}
 !2 = !{!"none"}
 !3 = !{!"int"}

 !84 = !{!"clk_event_t"}
 !opencl.ocl.version = !{!90}
 !90 = !{i32 2, i32 0}
+!100 = !{!"1:1:4:%d\5Cn"}
+!101 = !{!"2:1:8:%g\5Cn"}