[Hexagon] Simplify CFG after atomic expansion
This will remove suboptimal branching from the generated ll/sc loops.
The extra simplification pass affects a lot of testcases, which have
been modified to accommodate this change: either by modifying the
test to become immune to the CFG simplification, or (less preferablt)
by adding option -hexagon-initial-cfg-clenaup=0.
llvm-svn: 338774
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
index 2c75e91..c9ffc7e 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -97,6 +97,10 @@
static cl::opt<bool> EnableVExtractOpt("hexagon-opt-vextract", cl::Hidden,
cl::ZeroOrMore, cl::init(true), cl::desc("Enable vextract optimization"));
+static cl::opt<bool> EnableInitialCFGCleanup("hexagon-initial-cfg-cleanup",
+ cl::Hidden, cl::ZeroOrMore, cl::init(true),
+ cl::desc("Simplify the CFG after atomic expansion pass"));
+
/// HexagonTargetMachineModule - Note that this is used on hosts that
/// cannot link in a library unless there are references into the
/// library. In particular, it seems that it is not possible to get
@@ -311,7 +315,10 @@
}
addPass(createAtomicExpandPass());
+
if (!NoOpt) {
+ if (EnableInitialCFGCleanup)
+ addPass(createCFGSimplificationPass(1, true, true, false, true));
if (EnableLoopPrefetch)
addPass(createLoopDataPrefetchPass());
if (EnableCommGEP)