[AMDGPU][MC][GFX10] Enabled null with 64-bit operands

See Bug 42745: https://bugs.llvm.org/show_bug.cgi?id=42745

Reviewers: atamazov, arsenm

https://reviews.llvm.org/D65231

llvm-svn: 370660

Author: dpreobra

llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp

@@ -1854,6 +1854,8 @@ static bool isInlineValue(unsigned Reg) {
   case AMDGPU::SRC_EXECZ:
   case AMDGPU::SRC_SCC:
     return true;
+  case AMDGPU::SGPR_NULL:
+    return true;
   default:
     return false;
   }

llvm/test/MC/AMDGPU/reg-syntax-extra.s

@@ -116,6 +116,14 @@ v_mul_f32 v0, null, v2
 // NOSICIVI: error:
 // GFX10: v_mul_f32_e32 v0, null, v2      ; encoding: [0x7d,0x04,0x00,0x10]
 
+v_mul_f64 v[0:1], null, null
+// NOSICIVI: error:
+// GFX10: v_mul_f64 v[0:1], null, null    ; encoding: [0x00,0x00,0x65,0xd5,0x7d,0xfa,0x00,0x00]
+
 s_add_u32 null, null, null
 // NOSICIVI: error:
 // GFX10: s_add_u32 null, null, null      ; encoding: [0x7d,0x7d,0x7d,0x80]
+
+s_not_b64 s[2:3], null
+// NOSICIVI: error:
+// GFX10: s_not_b64 s[2:3], null          ; encoding: [0x7d,0x08,0x82,0xbe]