BackendUtil: Pass through -mdisable-tail-calls
The frontend option -fno-optimize-sibling-calls resolves to -cc1's
-mdisable-tail-calls, which is passed to the TargetMachine in the
backend. PassManagerBuilder was adding the -tailcallelim pass anyway.
Use a new DisableTailCalls option in PassManagerBuilder to disable tail
calls harder.
Requires the matching commit in LLVM that adds DisableTailCalls.
<rdar://problem/16050591>
llvm-svn: 206543
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index b75c62a..2c388ef 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -247,6 +247,7 @@
PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
+ PMBuilder.DisableTailCalls = CodeGenOpts.DisableTailCalls;
PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;