From: Chris Lattner <sabre@nondot.org>
Date: Fri, 15 Sep 2006 20:31:36 +0000 (+0000)
Subject: add a nate note
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cbce2f6c1b5b63b16b856f80e6fc026764b4eab4;p=oota-llvm.git

add a nate note


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30399 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 86c231bf319..1f982b7f76a 100644
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -240,4 +240,10 @@ _bar:   addic r3,r3,-1
         subfe r3,r3,r3
         blr
 
+//===---------------------------------------------------------------------===//
+
+Legalize should lower ctlz like this:
+  ctlz(x) = popcnt((x-1) & ~x)
+
+on targets that have popcnt but not ctlz.  itanium, what else?