[WebAssembly] Remove unneeded MCSymbolRefExpr variants

We record the type of the symbol (event/function/data/global) in the
MCWasmSymbol and so it should always be clear how to handle a relocation
based on the symbol itself.

The exception is a function which still needs the special @TYPEINDEX
then the relocation contains the signature rather than the address
of the functions.

Differential Revision: https://reviews.llvm.org/D58472

llvm-svn: 354697

1 files changed, 15 insertions, 38 deletions

diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
index 2c97aadd7f9..3b800858063 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
@@ -42,23 +42,8 @@ private:
 WebAssemblyWasmObjectWriter::WebAssemblyWasmObjectWriter(bool Is64Bit)
     : MCWasmObjectTargetWriter(Is64Bit) {}
 
-// Test whether the given expression computes a function address.
-static bool isFunctionExpr(const MCExpr *Expr) {
-  if (auto SyExp = dyn_cast<MCSymbolRefExpr>(Expr))
-    return cast<MCSymbolWasm>(SyExp->getSymbol()).isFunction();
-
-  if (auto BinOp = dyn_cast<MCBinaryExpr>(Expr))
-    return isFunctionExpr(BinOp->getLHS()) != isFunctionExpr(BinOp->getRHS());
-
-  if (auto UnOp = dyn_cast<MCUnaryExpr>(Expr))
-    return isFunctionExpr(UnOp->getSubExpr());
-
-  return false;
-}
-
-static bool isFunctionType(const MCValue &Target) {
-  const MCSymbolRefExpr *RefA = Target.getSymA();
-  return RefA && RefA->getKind() == MCSymbolRefExpr::VK_WebAssembly_TYPEINDEX;
+static bool isFunctionSignatureRef(const MCSymbolRefExpr *Ref) {
+  return Ref->getKind() == MCSymbolRefExpr::VK_WebAssembly_TYPEINDEX;
 }
 
 static const MCSection *getFixupSection(const MCExpr *Expr) {
@@ -80,41 +65,33 @@ static const MCSection *getFixupSection(const MCExpr *Expr) {
   return nullptr;
 }
 
-static bool isGlobalType(const MCValue &Target) {
-  const MCSymbolRefExpr *RefA = Target.getSymA();
-  return RefA && RefA->getKind() == MCSymbolRefExpr::VK_WebAssembly_GLOBAL;
-}
-
-static bool isEventType(const MCValue &Target) {
-  const MCSymbolRefExpr *RefA = Target.getSymA();
-  return RefA && RefA->getKind() == MCSymbolRefExpr::VK_WebAssembly_EVENT;
-}
-
 unsigned WebAssemblyWasmObjectWriter::getRelocType(const MCValue &Target,
                                                    const MCFixup &Fixup) const {
-  // WebAssembly functions are not allocated in the data address space. To
-  // resolve a pointer to a function, we must use a special relocation type.
-  bool IsFunction = isFunctionExpr(Fixup.getValue());
+  const MCSymbolRefExpr *RefA = Target.getSymA();
+  assert(RefA);
+  auto& SymA = cast<MCSymbolWasm>(RefA->getSymbol());
 
   switch (unsigned(Fixup.getKind())) {
   case WebAssembly::fixup_code_sleb128_i32:
-    if (IsFunction)
+    if (SymA.isFunction())
       return wasm::R_WASM_TABLE_INDEX_SLEB;
     return wasm::R_WASM_MEMORY_ADDR_SLEB;
   case WebAssembly::fixup_code_sleb128_i64:
     llvm_unreachable("fixup_sleb128_i64 not implemented yet");
   case WebAssembly::fixup_code_uleb128_i32:
-    if (isGlobalType(Target))
+    if (SymA.isFunction()) {
+      if (isFunctionSignatureRef(RefA))
+        return wasm::R_WASM_TYPE_INDEX_LEB;
+      else
+        return wasm::R_WASM_FUNCTION_INDEX_LEB;
+    }
+    if (SymA.isGlobal())
       return wasm::R_WASM_GLOBAL_INDEX_LEB;
-    if (isFunctionType(Target))
-      return wasm::R_WASM_TYPE_INDEX_LEB;
-    if (IsFunction)
-      return wasm::R_WASM_FUNCTION_INDEX_LEB;
-    if (isEventType(Target))
+    if (SymA.isEvent())
       return wasm::R_WASM_EVENT_INDEX_LEB;
     return wasm::R_WASM_MEMORY_ADDR_LEB;
   case FK_Data_4:
-    if (IsFunction)
+    if (SymA.isFunction())
       return wasm::R_WASM_TABLE_INDEX_I32;
     if (auto Section = static_cast<const MCSectionWasm *>(
             getFixupSection(Fixup.getValue()))) {