From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 10 Nov 2011 03:30:42 +0000 (+0000)
Subject: Temporary fix for a performance problem Eli spotted. The APValue representation
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1445bbacf4c8de5f208ff4ccb302424a4d9e233e;p=clang

Temporary fix for a performance problem Eli spotted. The APValue representation
is currently too inefficient to allow us to use it for array initializers, but
fortunately we usually don't yet need to evaluate such initializers.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144260 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index aa949907eb..f2e3d36d75 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -3391,6 +3391,12 @@ static bool EvaluateConstantExpression(APValue &Result, EvalInfo &Info,
 /// in Result. If this expression is a glvalue, an lvalue-to-rvalue conversion
 /// will be applied to the result.
 bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx) const {
+  // FIXME: Evaluating initializers for large arrays can cause performance
+  // problems, and we don't use such values yet. Once we have a more efficient
+  // array representation, this should be reinstated, and used by CodeGen.
+  if (isRValue() && getType()->isArrayType())
+    return false;
+
   EvalInfo Info(Ctx, Result);
 
   CCValue Value;