From: Daniel Dunbar <daniel@zuster.org>
Date: Thu, 4 Dec 2008 09:05:45 +0000 (+0000)
Subject: Mention an optimization opportunity pointed out by Chris.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=86ccea05f6bab8956f5418cdc4df8e130d4422aa;p=clang

Mention an optimization opportunity pointed out by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60535 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/README.txt b/lib/CodeGen/README.txt
index cda17ea97f..56069dd99d 100644
--- a/lib/CodeGen/README.txt
+++ b/lib/CodeGen/README.txt
@@ -18,3 +18,15 @@ directly.
 
 //===---------------------------------------------------------------------===//
 
+It may be worth avoiding creation of alloca's for formal arguments
+for the common situation where the argument is never written to or has
+its address taken. The idea would be to begin generating code by using
+the argument directly and if its address is taken or it is stored to
+then generate the alloca and patch up the existing code.
+
+In theory, the same optimization could be a win for block local
+variables as long as the declaration dominates all statements in the
+block.
+
+//===---------------------------------------------------------------------===//
+