[WebAssembly] Add an option to make get_local/set_local explicit.

This patch adds a pass, controlled by an option and off by default for
now, for making implicit get_local/set_local explicit. This simplifies
emitting wasm with MC.

Differential Revision: https://reviews.llvm.org/D25836

llvm-svn: 285009

1 files changed, 6 insertions, 22 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyPrepareForLiveIntervals.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyPrepareForLiveIntervals.cpp
index 52fdaf0417a..473dcb7a33f 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyPrepareForLiveIntervals.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyPrepareForLiveIntervals.cpp
@@ -23,6 +23,7 @@
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblySubtarget.h"
+#include "WebAssemblyUtilities.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -58,27 +59,10 @@ FunctionPass *llvm::createWebAssemblyPrepareForLiveIntervals() {
   return new WebAssemblyPrepareForLiveIntervals();
 }
 
-/// Test whether the given instruction is an ARGUMENT.
-static bool IsArgument(const MachineInstr *MI) {
-  switch (MI->getOpcode()) {
-  case WebAssembly::ARGUMENT_I32:
-  case WebAssembly::ARGUMENT_I64:
-  case WebAssembly::ARGUMENT_F32:
-  case WebAssembly::ARGUMENT_F64:
-  case WebAssembly::ARGUMENT_v16i8:
-  case WebAssembly::ARGUMENT_v8i16:
-  case WebAssembly::ARGUMENT_v4i32:
-  case WebAssembly::ARGUMENT_v4f32:
-    return true;
-  default:
-    return false;
-  }
-}
-
 // Test whether the given register has an ARGUMENT def.
 static bool HasArgumentDef(unsigned Reg, const MachineRegisterInfo &MRI) {
   for (const auto &Def : MRI.def_instructions(Reg))
-    if (IsArgument(&Def))
+    if (WebAssembly::isArgument(Def))
       return true;
   return false;
 }
@@ -126,10 +110,10 @@ bool WebAssemblyPrepareForLiveIntervals::runOnMachineFunction(MachineFunction &M
   // Move ARGUMENT_* instructions to the top of the entry block, so that their
   // liveness reflects the fact that these really are live-in values.
   for (auto MII = Entry.begin(), MIE = Entry.end(); MII != MIE; ) {
-    MachineInstr *MI = &*MII++;
-    if (IsArgument(MI)) {
-      MI->removeFromParent();
-      Entry.insert(Entry.begin(), MI);
+    MachineInstr &MI = *MII++;
+    if (WebAssembly::isArgument(MI)) {
+      MI.removeFromParent();
+      Entry.insert(Entry.begin(), &MI);
     }
   }