[WebAssembly] Optimize away return instructions using fallthroughs.

This saves a small amount of code size, and is a first small step toward
passing values on the stack across block boundaries.

Differential Review: http://reviews.llvm.org/D20450

llvm-svn: 270294

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index e4b049dd15d..32154af3c1c 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -225,10 +225,10 @@ void WebAssemblyPassConfig::addPreEmitPass() {
   // Lower br_unless into br_if.
   addPass(createWebAssemblyLowerBrUnless());
 
-  // Create a mapping from LLVM CodeGen virtual registers to wasm registers.
-  addPass(createWebAssemblyRegNumbering());
-
   // Perform the very last peephole optimizations on the code.
   if (getOptLevel() != CodeGenOpt::None)
     addPass(createWebAssemblyPeephole());
+
+  // Create a mapping from LLVM CodeGen virtual registers to wasm registers.
+  addPass(createWebAssemblyRegNumbering());
 }