[TableGen] Allow 2^63-1 and 2^63-2 as int literals.

These two values correspond to the 'Empty' and 'Tombstone' special
keys defined by DenseMapInfo<int64_t>, which means that neither one
can be used as a key in DenseMap<int64_t, anything>. Hence, if you try
to use either of those values as an int literal, IntInit::get() fails
an assertion when it tries to insert them into its static cache of
int-literal objects.

Fixed by replacing the DenseMap with a std::map, which doesn't intrude
on the space of legal values of the key type.

Reviewers: nhaehnle, hfinkel, javedabsar, efriedma

Reviewed By: efriedma

Subscribers: fhahn, efriedma, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59016

llvm-svn: 355900

llvm/lib/TableGen/Record.cpp

@@ -32,6 +32,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ -457,7 +458,7 @@ Init *BitsInit::resolveReferences(Resolver &R) const {
 }
 
 IntInit *IntInit::get(int64_t V) {
-  static DenseMap<int64_t, IntInit*> ThePool;
+  static std::map<int64_t, IntInit*> ThePool;
 
   IntInit *&I = ThePool[V];
   if (!I) I = new(Allocator) IntInit(V);

llvm/test/TableGen/IntSpecialValues.td

@@ -0,0 +1,8 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+
+def TestRecord {
+  // CHECK: int X = 9223372036854775807;
+  int X = 0x7FFFFFFFFFFFFFFF;
+  // CHECK: int Y = 9223372036854775806;
+  int Y = 0x7FFFFFFFFFFFFFFE;
+}