From 6a224c30a5d358305e6cfda1a62a78f658baa943 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Fri, 31 Jul 2015 01:12:06 +0000
Subject: [PATCH] TableGen: Support folding casts from bits to int

This is to fix an incorrect error when trying to initialize
DwarfNumbers with a !cast<int> of a bits initializer.
getValuesAsListOfInts("DwarfNumbers") would not see an IntInit
and instead the cast, so would give up.

It seems likely that this could be generalized to attempt
the convertInitializerTo for any type. I'm not really sure
why the existing code seems to special case the string cast cases
when convertInitializerTo seems like it should generally handle this
sort of thing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243722 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/TableGen/Record.cpp                |  8 ++++++++
 test/TableGen/cast-list-initializer.td | 10 ++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 test/TableGen/cast-list-initializer.td

diff --git a/lib/TableGen/Record.cpp b/lib/TableGen/Record.cpp
index c9a31b64cfd..271e52567a2 100644
--- a/lib/TableGen/Record.cpp
+++ b/lib/TableGen/Record.cpp
@@ -673,6 +673,14 @@ Init *UnOpInit::Fold(Record *CurRec, MultiClass *CurMultiClass) const {
         PrintFatalError(CurRec->getLoc(),
                         "Undefined reference:'" + Name + "'\n");
       }
+
+      if (isa<IntRecTy>(getType())) {
+        if (BitsInit *BI = dyn_cast<BitsInit>(LHS)) {
+          if (Init *NewInit = BI->convertInitializerTo(IntRecTy::get()))
+            return NewInit;
+          break;
+        }
+      }
     }
     break;
   }
diff --git a/test/TableGen/cast-list-initializer.td b/test/TableGen/cast-list-initializer.td
new file mode 100644
index 00000000000..4c83773a5a7
--- /dev/null
+++ b/test/TableGen/cast-list-initializer.td
@@ -0,0 +1,10 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+
+class Foo<bits<8> b> {
+// CHECK: list<int> ListOfInts = [170];
+// CHECK: list<int> AnotherList = [170, 7];
+  list<int> ListOfInts = [!cast<int>(b)];
+  list<int> AnotherList = [!cast<int>(b), !cast<int>({1, 1, 1})];
+}
+
+def : Foo<{1, 0, 1, 0, 1, 0, 1, 0}>;
-- 
2.34.1