[NVPTX] Added LDU/LDG intrinsics for f16.

[jlebar]

Do we not have tests for this? On the one hand it's kind of simple enough that it's not worth testing, but otoh it would be pretty annoying if it broke...

[tra]

Added one more missing load instruction variant for f16.

[tra]

I'll add proper tests along with the upcoming patch for lowering f16x2 ldg/ldu.

lib/Target/NVPTX/NVPTXIntrinsics.td

def ari64 :  NVPTXInst<(outs regclass:$result), (ins MEMri64:$src),
                !strconcat("ldu.global.", TyStr),
                         []>, Requires<[hasLDU]>;
 }
 
 defm INT_PTX_LDU_GLOBAL_i8  : LDU_G<"u8 \t$result, [$src];", Int16Regs>;
 defm INT_PTX_LDU_GLOBAL_i16 : LDU_G<"u16 \t$result, [$src];", Int16Regs>;
 defm INT_PTX_LDU_GLOBAL_i32 : LDU_G<"u32 \t$result, [$src];", Int32Regs>;
 defm INT_PTX_LDU_GLOBAL_i64 : LDU_G<"u64 \t$result, [$src];", Int64Regs>;
+defm INT_PTX_LDU_GLOBAL_f16 : LDU_G<"b16 \t$result, [$src];", Float16Regs>;
+defm INT_PTX_LDU_GLOBAL_f16x2 : LDU_G<"b32 \t$result, [$src];", Float16x2Regs>;
 defm INT_PTX_LDU_GLOBAL_f32 : LDU_G<"f32 \t$result, [$src];", Float32Regs>;
 defm INT_PTX_LDU_GLOBAL_f64 : LDU_G<"f64 \t$result, [$src];", Float64Regs>;
 defm INT_PTX_LDU_GLOBAL_p32 : LDU_G<"u32 \t$result, [$src];", Int32Regs>;
 defm INT_PTX_LDU_GLOBAL_p64 : LDU_G<"u64 \t$result, [$src];", Int64Regs>;
 
 // vector
 
 // Elementized vector ldu

 }
 
 defm INT_PTX_LDU_G_v2i8_ELE
   : VLDU_G_ELE_V2<"v2.u8 \t{{$dst1, $dst2}}, [$src];",  Int16Regs>;
 defm INT_PTX_LDU_G_v2i16_ELE
   : VLDU_G_ELE_V2<"v2.u16 \t{{$dst1, $dst2}}, [$src];", Int16Regs>;
 defm INT_PTX_LDU_G_v2i32_ELE
   : VLDU_G_ELE_V2<"v2.u32 \t{{$dst1, $dst2}}, [$src];", Int32Regs>;
+defm INT_PTX_LDU_G_v2f16_ELE
+  : VLDU_G_ELE_V2<"v2.b16 \t{{$dst1, $dst2}}, [$src];", Float16Regs>;
+defm INT_PTX_LDU_G_v2f16x2_ELE
+  : VLDU_G_ELE_V2<"v2.b32 \t{{$dst1, $dst2}}, [$src];", Float16x2Regs>;
 defm INT_PTX_LDU_G_v2f32_ELE
   : VLDU_G_ELE_V2<"v2.f32 \t{{$dst1, $dst2}}, [$src];", Float32Regs>;
 defm INT_PTX_LDU_G_v2i64_ELE
   : VLDU_G_ELE_V2<"v2.u64 \t{{$dst1, $dst2}}, [$src];", Int64Regs>;
 defm INT_PTX_LDU_G_v2f64_ELE
   : VLDU_G_ELE_V2<"v2.f64 \t{{$dst1, $dst2}}, [$src];", Float64Regs>;
 defm INT_PTX_LDU_G_v4i8_ELE
   : VLDU_G_ELE_V4<"v4.u8 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Int16Regs>;
 defm INT_PTX_LDU_G_v4i16_ELE
   : VLDU_G_ELE_V4<"v4.u16 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];",
     Int16Regs>;
 defm INT_PTX_LDU_G_v4i32_ELE
   : VLDU_G_ELE_V4<"v4.u32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];",
     Int32Regs>;
+defm INT_PTX_LDU_G_v4f16_ELE
+  : VLDU_G_ELE_V4<"v4.b16 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];",
+    Float16Regs>;
+defm INT_PTX_LDU_G_v4f16x2_ELE
+  : VLDU_G_ELE_V4<"v4.b32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];",
+    Float16x2Regs>;
 defm INT_PTX_LDU_G_v4f32_ELE
   : VLDU_G_ELE_V4<"v4.f32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];",
     Float32Regs>;
 
 
 //-----------------------------------
 // Support for ldg on sm_35 or later 
 //-----------------------------------

 
 // FIXME: 8-bit LDG should be fixed once LDG/LDU nodes are made into proper loads.
 defm INT_PTX_LDG_G_v2i8_ELE
   : VLDG_G_ELE_V2<"v2.u8 \t{{$dst1, $dst2}}, [$src];",  Int16Regs>;
 defm INT_PTX_LDG_G_v2i16_ELE
   : VLDG_G_ELE_V2<"v2.u16 \t{{$dst1, $dst2}}, [$src];", Int16Regs>;
 defm INT_PTX_LDG_G_v2i32_ELE
   : VLDG_G_ELE_V2<"v2.u32 \t{{$dst1, $dst2}}, [$src];", Int32Regs>;
-defm INT_PTX_LDG_G_v4f16_ELE
+defm INT_PTX_LDG_G_v2f16_ELE
+  : VLDG_G_ELE_V2<"v2.b16 \t{{$dst1, $dst2}}, [$src];", Float16Regs>;
+defm INT_PTX_LDG_G_v2f16x2_ELE
   : VLDG_G_ELE_V2<"v2.b32 \t{{$dst1, $dst2}}, [$src];", Float16x2Regs>;
 defm INT_PTX_LDG_G_v2f32_ELE
   : VLDG_G_ELE_V2<"v2.f32 \t{{$dst1, $dst2}}, [$src];", Float32Regs>;
 defm INT_PTX_LDG_G_v2i64_ELE
   : VLDG_G_ELE_V2<"v2.u64 \t{{$dst1, $dst2}}, [$src];", Int64Regs>;
 defm INT_PTX_LDG_G_v2f64_ELE
   : VLDG_G_ELE_V2<"v2.f64 \t{{$dst1, $dst2}}, [$src];", Float64Regs>;
 defm INT_PTX_LDG_G_v4i8_ELE
   : VLDG_G_ELE_V4<"v4.u8 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Int16Regs>;
 defm INT_PTX_LDG_G_v4i16_ELE
   : VLDG_G_ELE_V4<"v4.u16 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Int16Regs>;
 defm INT_PTX_LDG_G_v4i32_ELE
   : VLDG_G_ELE_V4<"v4.u32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Int32Regs>;
-defm INT_PTX_LDG_G_v8f16_ELE
+defm INT_PTX_LDG_G_v4f16_ELE
+  : VLDG_G_ELE_V4<"v4.b16 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Float16Regs>;
+defm INT_PTX_LDG_G_v4f16x2_ELE
   : VLDG_G_ELE_V4<"v4.b32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Float16x2Regs>;
 defm INT_PTX_LDG_G_v4f32_ELE
   : VLDG_G_ELE_V4<"v4.f32 \t{{$dst1, $dst2, $dst3, $dst4}}, [$src];", Float32Regs>;
 
 
 multiclass NG_TO_G<string Str, Intrinsic Intrin> {
    def _yes : NVPTXInst<(outs Int32Regs:$result), (ins Int32Regs:$src),
           !strconcat("cvta.", Str, ".u32 \t$result, $src;"),