From e6de9f30cbdbeca7f6632420f2cd5728d9a2dc1c Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Thu, 20 Oct 2011 17:31:18 +0000 Subject: [PATCH] Add a comment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142592 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineLICM.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp index 969a9b084d5..c693386f9bb 100644 --- a/lib/CodeGen/MachineLICM.cpp +++ b/lib/CodeGen/MachineLICM.cpp @@ -788,7 +788,9 @@ bool MachineLICM::IsLICMCandidate(MachineInstr &I) { // If it is load then check if it is guaranteed to execute by making sure that // it dominates all exiting blocks. If it doesn't, then there is a path out of - // the loop which does not execute this load, so we can't hoist it. + // the loop which does not execute this load, so we can't hoist it. Loads + // from constant memory are not safe to speculate all the time, for example + // indexed load from a jump table. // Stores and side effects are already checked by isSafeToMove. if (I.getDesc().mayLoad() && !isLoadFromGOT(I) && !IsGuaranteedToExecute(I.getParent())) -- 2.34.1