[MC][WebAssembly] For type checking for bulk memory instructions

[sbc100]

Summary

This code currently assumes that all bulk memory operations occur on
memory 0 which who's type is determined by the wasm32 vs wasm64 target
triple. Further improvement would be need to support multi-memory.

[sbc100]

• revert

[sbc100]

This following emscripten change is currently blocked due to this bug: https://github.com/emscripten-core/emscripten/pull/19128

[tlively]

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.cpp

283

For memory.init, the correct type should be [ptr i32 i32] -> [] acording to https://github.com/WebAssembly/memory64/blob/main/proposals/memory64/Overview.md#:~:text=grow%20%3A%20%5Bit%5D%20%E2%86%92%20%5Bit%5D-,memory,-.fill

[tlively]

LGTM with the type fixed.

[sbc100]

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.cpp

283

Good point... I guess it was decided that each individual segment could never exceed i32 space?

[sbc100]

• feedback

[tlively]

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.cpp

283

Yeah, I guess that's the reason.

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.cpp

return typeError(ErrorLoc, StringRef("no local type specified for index ") +
                           std::to_string(Local));
   Type = LocalTypes[Local];
   return false;
 }
 
 bool WebAssemblyAsmTypeCheck::checkEnd(SMLoc ErrorLoc, bool PopVals) {
   if (LastSig.Returns.size() > Stack.size())
     return typeError(ErrorLoc, "end: insufficient values on the type stack");
-  
   if (PopVals) {
     for (auto VT : llvm::reverse(LastSig.Returns)) {
-      if (popType(ErrorLoc, VT)) 
+      if (popType(ErrorLoc, VT))
         return true;
     }
     return false;
   }
-  
   for (size_t i = 0; i < LastSig.Returns.size(); i++) {
     auto EVT = LastSig.Returns[i];
     auto PVT = Stack[Stack.size() - LastSig.Returns.size() + i];
     if (PVT != EVT)
       return typeError(
           ErrorLoc, StringRef("end got ") + WebAssembly::typeToString(PVT) +
                         ", expected " + WebAssembly::typeToString(EVT));
   }
if (Name == "local.get") {
     if (getTable(Operands[1]->getStartLoc(), Inst, Type))
       return true;
     if (popType(ErrorLoc, wasm::ValType::I32))
       return true;
     if (popType(ErrorLoc, Type))
       return true;
     if (popType(ErrorLoc, wasm::ValType::I32))
       return true;
+  } else if (Name == "memory.fill") {
+    Type = is64 ? wasm::ValType::I64 : wasm::ValType::I32;
+    if (popType(ErrorLoc, Type))
+      return true;
+    if (popType(ErrorLoc, wasm::ValType::I32))
+      return true;
+    if (popType(ErrorLoc, Type))
+      return true;
+  } else if (Name == "memory.copy") {
+    Type = is64 ? wasm::ValType::I64 : wasm::ValType::I32;
+    if (popType(ErrorLoc, Type))
+      return true;
+    if (popType(ErrorLoc, Type))
+      return true;
+    if (popType(ErrorLoc, Type))
+      return true;
+  } else if (Name == "memory.init") {
+    Type = is64 ? wasm::ValType::I64 : wasm::ValType::I32;
+    if (popType(ErrorLoc, wasm::ValType::I32))
+      return true;
+    if (popType(ErrorLoc, wasm::ValType::I32))
+      return true;
+    if (popType(ErrorLoc, Type))
+      return true;
   } else if (Name == "drop") {
     if (popType(ErrorLoc, {}))
       return true;
   } else if (Name == "end_block" || Name == "end_loop" || Name == "end_if" ||
              Name == "else" || Name == "end_try") {
     if (checkEnd(ErrorLoc, Name == "else"))
       return true;
     if (Name == "end_block")

llvm/test/MC/WebAssembly/bulk-memory-encodings.s

-# RUN: llvm-mc -show-encoding -no-type-check -triple=wasm32-unknown-unknown -mattr=+bulk-memory < %s | FileCheck %s
-# RUN: llvm-mc -show-encoding -no-type-check -triple=wasm64-unknown-unknown -mattr=+bulk-memory < %s | FileCheck %s
+# RUN: split-file %s %t
+# RUN: llvm-mc -show-encoding -triple=wasm32-unknown-unknown -mattr=+bulk-memory < %t/wasm32.s | FileCheck %s
+# RUN: llvm-mc -show-encoding -triple=wasm64-unknown-unknown -mattr=+bulk-memory < %t/wasm64.s | FileCheck %s
 
+#--- wasm32.s
 main:
     .functype main () -> ()
 
+    i32.const 2 # dest address
+    i32.const 3 # src offset
+    i32.const 4 # count
     # CHECK: memory.init 3, 0 # encoding: [0xfc,0x08,0x03,0x00]
     memory.init 3, 0
 
     # CHECK: data.drop 3 # encoding: [0xfc,0x09,0x03]
     data.drop 3
 
+    i32.const 2 # dst
+    i32.const 3 # src
+    i32.const 4 # count
     # CHECK: memory.copy 0, 0 # encoding: [0xfc,0x0a,0x00,0x00]
     memory.copy 0, 0
 
+    i32.const 2 # addr
+    i32.const 3 # val
+    i32.const 4 # count
     # CHECK: memory.fill 0 # encoding: [0xfc,0x0b,0x00]
     memory.fill 0
 
     end_function
+
+#--- wasm64.s
+main:
+    .functype main () -> ()
+
+    i64.const 2 # dest address
+    i32.const 3 # src offset
+    i32.const 4 # count
+    memory.init 3, 0
+
+    data.drop 3
+
+    i64.const 2 # dst
+    i64.const 3 # src
+    i64.const 4 # count
+    memory.copy 0, 0
+
+    i64.const 2 # addr
+    i32.const 3 # val
+    i64.const 4 # count
+    memory.fill 0
+
+    end_function