[RISCV][NFC] Define scalable vectors for half types.

[HsiangKai]

Summary

This is a preperation work for vfadd intrinsics.

[craig.topper]

LGTM

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

if (Subtarget.hasStdExtV()) {
     addRegisterClass(RISCVVMVTs::vint32m4_t, &RISCV::VRM4RegClass);
     addRegisterClass(RISCVVMVTs::vint32m8_t, &RISCV::VRM8RegClass);
 
     addRegisterClass(RISCVVMVTs::vint64m1_t, &RISCV::VRRegClass);
     addRegisterClass(RISCVVMVTs::vint64m2_t, &RISCV::VRM2RegClass);
     addRegisterClass(RISCVVMVTs::vint64m4_t, &RISCV::VRM4RegClass);
     addRegisterClass(RISCVVMVTs::vint64m8_t, &RISCV::VRM8RegClass);
 
+    addRegisterClass(RISCVVMVTs::vfloat16mf4_t, &RISCV::VRRegClass);
+    addRegisterClass(RISCVVMVTs::vfloat16mf2_t, &RISCV::VRRegClass);
+    addRegisterClass(RISCVVMVTs::vfloat16m1_t, &RISCV::VRRegClass);
+    addRegisterClass(RISCVVMVTs::vfloat16m2_t, &RISCV::VRM2RegClass);
+    addRegisterClass(RISCVVMVTs::vfloat16m4_t, &RISCV::VRM4RegClass);
+    addRegisterClass(RISCVVMVTs::vfloat16m8_t, &RISCV::VRM8RegClass);
+
     addRegisterClass(RISCVVMVTs::vfloat32mf2_t, &RISCV::VRRegClass);
     addRegisterClass(RISCVVMVTs::vfloat32m1_t, &RISCV::VRRegClass);
     addRegisterClass(RISCVVMVTs::vfloat32m2_t, &RISCV::VRM2RegClass);
     addRegisterClass(RISCVVMVTs::vfloat32m4_t, &RISCV::VRM4RegClass);
     addRegisterClass(RISCVVMVTs::vfloat32m8_t, &RISCV::VRM8RegClass);
 
     addRegisterClass(RISCVVMVTs::vfloat64m1_t, &RISCV::VRRegClass);
     addRegisterClass(RISCVVMVTs::vfloat64m2_t, &RISCV::VRM2RegClass);

llvm/lib/Target/RISCV/RISCVRegisterInfo.td

 defvar vint32m4_t  = nxv8i32;
 defvar vint32m8_t  = nxv16i32;
 
 defvar vint64m1_t = nxv1i64;
 defvar vint64m2_t = nxv2i64;
 defvar vint64m4_t = nxv4i64;
 defvar vint64m8_t = nxv8i64;
 
+defvar vfloat16mf4_t = nxv1f16;
+defvar vfloat16mf2_t = nxv2f16;
+defvar vfloat16m1_t  = nxv4f16;
+defvar vfloat16m2_t  = nxv8f16;
+defvar vfloat16m4_t  = nxv16f16;
+defvar vfloat16m8_t  = nxv32f16;
+
 defvar vfloat32mf2_t = nxv1f32;
 defvar vfloat32m1_t  = nxv2f32;
 defvar vfloat32m2_t  = nxv4f32;
 defvar vfloat32m4_t  = nxv8f32;
 defvar vfloat32m8_t  = nxv16f32;
 
 defvar vfloat64m1_t = nxv1f64;
 defvar vfloat64m2_t = nxv2f64;
: RegisterClass<"RISCV",
                   regList> {
   int VLMul = Vlmul;
   int Size = !mul(Vlmul, 64); // FIXME: assuming ELEN=64
 }
 
 def VR : VReg<[vint8mf2_t, vint8mf4_t, vint8mf8_t,
                vint16mf2_t, vint16mf4_t, vint32mf2_t,
                vint8m1_t, vint16m1_t, vint32m1_t, vint64m1_t,
+               vfloat16mf4_t, vfloat16mf2_t, vfloat16m1_t,
                vfloat32mf2_t, vfloat32m1_t, vfloat64m1_t,
                vbool64_t, vbool32_t, vbool16_t, vbool8_t, vbool4_t,
                vbool2_t, vbool1_t],
            (add (sequence "V%u", 25, 31),
                 (sequence "V%u", 8, 24),
                 (sequence "V%u", 0, 7)), 1>;
 
 def VRNoV0 : VReg<[vint8mf2_t, vint8mf4_t, vint8mf8_t,
                    vint16mf2_t, vint16mf4_t, vint32mf2_t,
                    vint8m1_t, vint16m1_t, vint32m1_t, vint64m1_t,
+                   vfloat16mf4_t, vfloat16mf2_t, vfloat16m1_t,
                    vfloat32mf2_t, vfloat32m1_t, vfloat64m1_t,
                    vbool64_t, vbool32_t, vbool16_t, vbool8_t, vbool4_t,
                    vbool2_t, vbool1_t],
                (add (sequence "V%u", 25, 31),
                     (sequence "V%u", 8, 24),
                     (sequence "V%u", 1, 7)), 1>;
 
 def VRM2 : VReg<[vint8m2_t, vint16m2_t, vint32m2_t, vint64m2_t,
-                 vfloat32m2_t, vfloat64m2_t],
+                 vfloat16m2_t, vfloat32m2_t, vfloat64m2_t],
              (add V26M2, V28M2, V30M2, V8M2, V10M2, V12M2, V14M2, V16M2,
                   V18M2, V20M2, V22M2, V24M2, V0M2, V2M2, V4M2, V6M2), 2>;
 
 def VRM2NoV0 : VReg<[vint8m2_t, vint16m2_t, vint32m2_t, vint64m2_t,
-                     vfloat32m2_t, vfloat64m2_t],
+                     vfloat16m2_t, vfloat32m2_t, vfloat64m2_t],
                  (add V26M2, V28M2, V30M2, V8M2, V10M2, V12M2, V14M2, V16M2,
                       V18M2, V20M2, V22M2, V24M2, V2M2, V4M2, V6M2), 2>;
 
 def VRM4 : VReg<[vint8m4_t, vint16m4_t, vint32m4_t, vint64m4_t,
-                 vfloat32m4_t, vfloat64m4_t],
+                 vfloat16m4_t, vfloat32m4_t, vfloat64m4_t],
              (add V28M4, V8M4, V12M4, V16M4, V20M4, V24M4, V0M4, V4M4), 4>;
 
 def VRM4NoV0 : VReg<[vint8m4_t, vint16m4_t, vint32m4_t, vint64m4_t,
-                     vfloat32m4_t, vfloat64m4_t],
+                     vfloat16m4_t, vfloat32m4_t, vfloat64m4_t],
                  (add V28M4, V8M4, V12M4, V16M4, V20M4, V24M4, V4M4), 4>;
 
 def VRM8 : VReg<[vint8m8_t, vint16m8_t, vint32m8_t, vint64m8_t,
-                 vfloat32m8_t, vfloat64m8_t],
+                 vfloat16m8_t, vfloat32m8_t, vfloat64m8_t],
              (add V8M8, V16M8, V24M8, V0M8), 8>;
 
 def VRM8NoV0 : VReg<[vint8m8_t, vint16m8_t, vint32m8_t, vint64m8_t,
-                     vfloat32m8_t, vfloat64m8_t],
+                     vfloat16m8_t, vfloat32m8_t, vfloat64m8_t],
                  (add V8M8, V16M8, V24M8), 8>;
 
 defvar VMaskVTs = [vbool64_t, vbool32_t, vbool16_t, vbool8_t,
                    vbool4_t, vbool2_t, vbool1_t];
 
 def VMV0 : RegisterClass<"RISCV", VMaskVTs, 64, (add V0)> {
   let Size = 64;
 }