Enable on-demand fast-isel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107377 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 3b0ef18..0848e46 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -709,6 +709,12 @@
FastIS->startNewBlock(BB);
// Do FastISel on as many instructions as possible.
for (; BI != End; ++BI) {
+ // Defer instructions with no side effects; they'll be emitted
+ // on-demand later.
+ if (BI->isSafeToSpeculativelyExecute() &&
+ !FuncInfo->ValueMap.count(BI))
+ continue;
+
// Try to select the instruction with FastISel.
if (FastIS->SelectInstruction(BI))
continue;