Index: lib/Target/Mips/AsmParser/MipsAsmParser.cpp
===================================================================
--- lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -4784,8 +4784,11 @@
 
   warnIfRegIndexIsAT(FirstReg, IDLoc);
 
-  assert(Inst.getOperand(2).isImm() &&
-         "Offset for load macro is not immediate!");
+  if (!Inst.getOperand(2).isImm()) {
+    const StringRef InstName = (IsLoad ? "ld" : "sd");
+    return Error(IDLoc,
+                 "offset for " + InstName + " macro is not an immediate");
+  }
 
   MCOperand &FirstOffset = Inst.getOperand(2);
   signed NextOffset = FirstOffset.getImm() + 4;
Index: test/MC/Mips/macro-sd.s
===================================================================
--- /dev/null
+++ test/MC/Mips/macro-sd.s
@@ -0,0 +1,24 @@
+# RUN: llvm-mc -triple mips-unknown-freebsd -show-encoding %s | FileCheck %s
+# RUN: not llvm-mc -triple mips-unknown-freebsd -show-encoding %s -defsym=BAD_MACRO=1 2>&1 | FileCheck -check-prefix=ERR %s
+.data
+.globl fenvp
+fenvp:
+.space 8
+
+
+.set noreorder
+.text
+_start:
+
+.ifdef BAD_MACRO
+# These are not expected to work:
+sd $6, fenvp  # ERR: macro-sd.s:[[@LINE]]:1: error: offset for sd macro is not an immediate
+ld $6, fenvp  # ERR: macro-sd.s:[[@LINE]]:1: error: offset for ld macro is not an immediate
+.else
+sd $6, 0($2)
+# CHECK:      sw      $6, 0($2)               # encoding: [0xac,0x46,0x00,0x00]
+# CHECK-NEXT: sw      $7, 4($2)               # encoding: [0xac,0x47,0x00,0x04]
+ld $6, 0($2)
+# CHECK:      lw      $6, 0($2)               # encoding: [0x8c,0x46,0x00,0x00]
+# CHECK-NEXT: lw      $7, 4($2)               # encoding: [0x8c,0x47,0x00,0x04]
+.endif