Disable most IR-level transform passes on functions marked 'optnone'.

Ideally only those transform passes that run at -O0 remain enabled,
in reality we get as close as we reasonably can.
Passes are responsible for disabling themselves, it's not the job of
the pass manager to do it for them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200892 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -1801,6 +1801,9 @@ void IndVarSimplify::SinkUnusedInvariants(Loop *L) {
 //===----------------------------------------------------------------------===//
 
 bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
+  if (skipOptnoneFunction(L))
+    return false;
+
   // If LoopSimplify form is not available, stay out of trouble. Some notes:
   //  - LSR currently only supports LoopSimplify-form loops. Indvars'
   //    canonicalization can be a pessimization without LSR to "clean up"