Index: lib/Target/Mips/AsmParser/MipsAsmParser.cpp
===================================================================
--- lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -199,7 +199,7 @@
 
   unsigned getGPR(int RegNo);
 
-  int getATReg();
+  int getATReg(SMLoc Loc);
 
   bool processInstruction(MCInst &Inst, SMLoc IDLoc,
                           SmallVectorImpl<MCInst> &Instructions);
@@ -1127,9 +1127,15 @@
   // but for stores we must use $at.
   if (isLoad && (BaseRegNum != RegOpNum))
     TmpRegNum = RegOpNum;
-  else
-    TmpRegNum = getReg(
-      (isGP64()) ? Mips::GPR64RegClassID : Mips::GPR32RegClassID, getATReg());
+  else {
+    int AT = getATReg(IDLoc);
+    // At this point we need AT to perform the expansions and we exit if it is
+    // not available.
+    if (!AT)
+      return;
+    TmpRegNum =
+        getReg((isGP64()) ? Mips::GPR64RegClassID : Mips::GPR32RegClassID, AT);
+  }
 
   TempInst.setOpcode(Mips::LUi);
   TempInst.addOperand(MCOperand::CreateReg(TmpRegNum));
@@ -1386,10 +1392,11 @@
   return true;
 }
 
-int MipsAsmParser::getATReg() {
+int MipsAsmParser::getATReg(SMLoc Loc) {
   int AT = Options.getATRegNum();
   if (AT == 0)
-    TokError("Pseudo instruction requires $at, which is not available");
+    reportParseError(Loc,
+                     "Pseudo instruction requires $at, which is not available");
   return AT;
 }
 
Index: test/MC/Mips/mips-noat.s
===================================================================
--- test/MC/Mips/mips-noat.s
+++ test/MC/Mips/mips-noat.s
@@ -10,11 +10,10 @@
 test1:
         lw      $2, 65536($2)
 
-# FIXME: It would be better if the error pointed at the mnemonic instead of the newline
-# ERROR: mips-noat.s:[[@LINE+4]]:1: error: Pseudo instruction requires $at, which is not available
 test2:
         .set noat
-        lw      $2, 65536($2)
+        lw      $2, 65536($2) # ERROR: mips-noat.s:[[@LINE]]:9: error: Pseudo instruction requires $at, which is not available
+
 
 # Can we switch it back on successfully?
 # CHECK-LABEL: test3:
@@ -25,10 +24,6 @@
         .set at
         lw      $2, 65536($2)
 
-# FIXME: It would be better if the error pointed at the mnemonic instead of the newline
-# ERROR: mips-noat.s:[[@LINE+4]]:1: error: Pseudo instruction requires $at, which is not available
 test4:
         .set at=$0
-        lw      $2, 65536($2)
-
-# ERROR-NOT: error
+        lw      $2, 65536($2) # ERROR: mips-noat.s:[[@LINE]]:9: error: Pseudo instruction requires $at, which is not available