tag doubles

Author: tgymnich

src/device/intrinsics/output.jl

@@ -7,6 +7,8 @@ const __METAL_OS_LOG_TYPE_DEFAULT__ = Int32(0)
 const __METAL_OS_LOG_TYPE_ERROR__ = Int32(16)
 const __METAL_OS_LOG_TYPE_FAULT__ = Int32(17)
 
+const ALLOW_DOUBLE_META = "allowdouble"
+
 export @mtlprintf
 
 @generated function promote_c_argument(arg)
@@ -18,13 +20,38 @@ export @mtlprintf
 
     if arg == Cchar || arg == Cshort
         return :(Cint(arg))
-    elseif arg == Cfloat
-        return :(Cdouble(arg))
     else
         return :(arg)
     end
 end
 
+@generated function tag_doubles(arg)
+    @dispose ctx=Context() begin
+        ret = arg == Cfloat ? Culong : arg
+        T_arg = convert(LLVMType, arg)
+        T_ret = convert(LLVMType, ret)
+
+        f, ft = create_function(T_ret, [T_arg])
+
+        @dispose builder=IRBuilder() begin
+            entry = BasicBlock(f, "entry")
+            position!(builder, entry)
+
+            p1 = parameters(f)[1]
+
+            if arg == Cfloat
+                res = fpext!(builder, p1, LLVM.DoubleType())
+                metadata(res)["annotation"] = MDNode([MDString(ALLOW_DOUBLE_META)])
+                ret!(builder, res) 
+            else
+                ret!(builder, p1) 
+            end
+        end
+
+        call_function(f, ret, Tuple{arg}, :arg)
+    end
+end
+
 """
     @mtlprintf("%Fmt", args...)
 
@@ -33,7 +60,7 @@ Print a formatted string in device context on the host standard output.
 macro mtlprintf(fmt::String, args...)
     fmt_val = Val(Symbol(fmt))
 
-    return :(_mtlprintf($fmt_val, $(map(arg -> :(promote_c_argument($arg)), esc.(args))...)))
+    return :(_mtlprintf($fmt_val, $(map(arg -> :(tag_doubles(promote_c_argument($arg))), esc.(args))...)))
 end
 
 @generated function _mtlprintf(::Val{fmt}, argspec...) where {fmt}
@@ -72,7 +99,10 @@ end
                 args = alloca!(builder, argtypes)
                 for (i, param) in enumerate(parameters(llvm_f))
                     p = struct_gep!(builder, argtypes, args, i-1)
-                    store!(builder, param, p)
+                    st = store!(builder, param, p)
+                    if param_types[i] == LLVM.DoubleType()
+                        metadata(st)["annotation"] = MDNode([MDString(ALLOW_DOUBLE_META)])
+                    end
                 end
 
                 dl = datalayout(mod)