[WebAssembly] Add a TODO comment for a possible future optimization.
llvm-svn: 256306
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
index 0a94533..f621db0 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegNumbering.cpp
@@ -82,7 +82,8 @@
}
// Then assign regular WebAssembly registers for all remaining used
- // virtual registers.
+ // virtual registers. TODO: Consider sorting the registers by frequency of
+ // use, to maximize usage of small immediate fields.
unsigned NumArgRegs = MFI.getParams().size();
unsigned NumVRegs = MF.getRegInfo().getNumVirtRegs();
unsigned NumStackRegs = 0;