From: Eli Friedman <eli.friedman@gmail.com>
Date: Sun, 24 May 2009 20:32:10 +0000 (+0000)
Subject: Add a comment which should hopefully make the purpose of this method a
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c046c00d0a1f65483a8c69f26c66fc74f5228332;p=oota-llvm.git

Add a comment which should hopefully make the purpose of this method a
bit clearer.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72374 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index b6f74aea41a..693ac68e30b 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -224,6 +224,9 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
 }
 
 SDValue VectorLegalizer::PromoteVectorOp(SDValue Op) {
+  // Vector "promotion" is basically just bitcasting and doing the operation
+  // in a different type.  For example, x86 promotes ISD::AND on v2i32 to
+  // v1i64.
   MVT VT = Op.getValueType();
   assert(Op.getNode()->getNumValues() == 1 &&
          "Can't promote a vector with multiple results!");