Teach SimplifyCFG how to simplify indirectbr instructions.
- Eliminate redundant successors.
- Convert an indirectbr with one successor into a direct branch.
Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111060 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index df6ef2e..360749c 100644
--- a/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -285,10 +285,9 @@
while (LocalChange) {
LocalChange = false;
- // Loop over all of the basic blocks (except the first one) and remove them
- // if they are unneeded...
+ // Loop over all of the basic blocks and remove them if they are unneeded...
//
- for (Function::iterator BBIt = ++F.begin(); BBIt != F.end(); ) {
+ for (Function::iterator BBIt = F.begin(); BBIt != F.end(); ) {
if (SimplifyCFG(BBIt++, TD)) {
LocalChange = true;
++NumSimpl;