From: Bill Wendling <isanbard@gmail.com>
Date: Thu, 25 Oct 2007 18:23:45 +0000 (+0000)
Subject: Added comment explaining why we are doing this check.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=0713a224234b4596709c7582ebf17a1ccb95c872;p=oota-llvm.git

Added comment explaining why we are doing this check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43353 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index d523bf585ae..021001d15fc 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -272,6 +272,11 @@ static unsigned ComputeCommonTailLength(MachineBasicBlock *MBB1,
   while (I1 != MBB1->begin() && I2 != MBB2->begin()) {
     --I1; --I2;
     if (!I1->isIdenticalTo(I2) || 
+        // XXX: This check is dubious. It's used to get around a problem where
+        // people incorrectly expect inline asm directives to remain in the same
+        // relative order. This is untenable because normal compiler
+        // optimizations (like this one) may reorder and/or merge these
+        // directives.
         I1->getOpcode() == TargetInstrInfo::INLINEASM) {
       ++I1; ++I2;
       break;