[X86][FastISel] Bail out on large objects when materializing a GlobalValue

To avoid crashes with explicitly large objects.

I will clean up fast-isel with large objects/medium code model soon.

Author: aeubanks

llvm/lib/Target/X86/X86FastISel.cpp

@@ -714,6 +714,12 @@ bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) {
     if (TM.getCodeModel() != CodeModel::Small)
       return false;
 
+    // Can't handle large objects yet.
+    if (auto *GO = dyn_cast<GlobalObject>(GV)) {
+      if (TM.isLargeGlobalObject(GO))
+        return false;
+    }
+
     // Can't handle TLS yet.
     if (GV->isThreadLocal())
       return false;

llvm/test/CodeGen/X86/fast-isel-large-object.ll

@@ -0,0 +1,13 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc -fast-isel -mtriple=x86_64-unknown-unknown -relocation-model=pic < %s | FileCheck %s
+
+@g = external dso_local global i32, code_model "large"
+
+define ptr @f() {
+; CHECK-LABEL: f:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    leaq _GLOBAL_OFFSET_TABLE_(%rip), %rax
+; CHECK-NEXT:    leaq g@GOTOFF(%rax), %rax
+; CHECK-NEXT:    retq
+  ret ptr @g
+}