Fix yet another memory leak found by the vg-leak bot. Folks (including

me) should start watching this bot more as its catching lots of bugs.

The fix here is to not construct the global if we aren't going to need
it. That's cheaper anyways, and globals have highly predictable types in
practice. I've added an assert to catch skew between our manual testing
of the type and the actual type just for paranoia's sake.

Note that this pattern is actually fine in most globals because when you
build a global with a module it automatically is moved to be owned by
that module. But here, we're in isel and don't really want to do that.
The solution of not creating a global is simpler anyways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187302 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index d4aa2f2548559648bbbcf3bbda43785c3c3b8ead..ed054aaf4d4aa6a4a42c06931d104f40d4a9d838 100644 (file)
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -2185,10 +2185,14 @@ unsigned ARMFastISel::ARMSelectCallOp(bool UseReg) {
 }
 
 unsigned ARMFastISel::getLibcallReg(const Twine &Name) {
+  // Manually compute the global's type to avoid building it when unnecessary.
+  Type *GVTy = Type::getInt32PtrTy(*Context, /*AS=*/0);
+  EVT LCREVT = TLI.getValueType(GVTy);
+  if (!LCREVT.isSimple()) return 0;
+
   GlobalValue *GV = new GlobalVariable(Type::getInt32Ty(*Context), false,
                                        GlobalValue::ExternalLinkage, 0, Name);
-  EVT LCREVT = TLI.getValueType(GV->getType());
-  if (!LCREVT.isSimple()) return 0;
+  assert(GV->getType() == GVTy && "We miscomputed the type for the global!");
   return ARMMaterializeGV(GV, LCREVT.getSimpleVT());
 }