[WebAssembly] Add some comments. NFC.
llvm-svn: 254096
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 2933294..c98bea9 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -187,7 +187,12 @@
void WebAssemblyPassConfig::addPreSched2() {}
void WebAssemblyPassConfig::addPreEmitPass() {
+ // Put the CFG in structured form; insert BLOCK and LOOP markers.
addPass(createWebAssemblyCFGStackify());
+
+ // Create a mapping from LLVM CodeGen virtual registers to wasm registers.
addPass(createWebAssemblyRegNumbering());
+
+ // Perform the very last peephole optimizations on the code.
addPass(createWebAssemblyPeephole());
}