Fix build warning introduced in r270552 "[AMDGPU][llvm-mc] Disassembler: support for TTMP/TBA/TMA registers."

llvm-svn: 270859
diff --git a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
index f1ee412..a76c0de 100644
--- a/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
+++ b/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp
@@ -359,7 +359,8 @@
   if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
     return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
   }
-  if (SGPR_MIN <= Val && Val <= SGPR_MAX) {
+  if (Val <= SGPR_MAX) {
+    assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
   }
   if (TTMP_MIN <= Val && Val <= TTMP_MAX) {