Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2086,8 +2086,12 @@
   MCValue MV;
   if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
     return;
+  const MCSymbolRefExpr *SymA = MV.getSymA();
+  if (!SymA)
+    return;
 
-  const MCSymbol *GOTEquivSym = &MV.getSymA()->getSymbol();
+  // Check that GOT equivalent symbol is cached.
+  const MCSymbol *GOTEquivSym = &SymA->getSymbol();
   if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
     return;
 
@@ -2095,8 +2099,11 @@
   if (!BaseGV)
     return;
 
+  // Check for a valid base symbol
   const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
-  if (BaseSym != &MV.getSymB()->getSymbol())
+  const MCSymbolRefExpr *SymB = MV.getSymB();
+
+  if (!SymB || BaseSym != &SymB->getSymbol())
     return;
 
   // Make sure to match:
Index: test/MC/MachO/cstexpr-gotpcrel-64.ll
===================================================================
--- test/MC/MachO/cstexpr-gotpcrel-64.ll
+++ test/MC/MachO/cstexpr-gotpcrel-64.ll
@@ -84,3 +84,12 @@
 define i32** @t1() {
   ret i32** @bargotequiv
 }
+
+; Do not crash when a pattern cannot be matched as a GOT equivalent
+
+@a = external global i8
+@b = internal unnamed_addr constant i8* @a
+
+; X86-LABEL: _c:
+; X86:   .quad _b
+@c = global i8** @b