[WebAssembly] Add multiple memories feature

[ashleynh]

Summary

Adding to allow users to get this flag into the target features section for future use cases.

[tlively]

The other file to update here is clang/test/Driver/wasm-features.c. It looks like we haven't been as consistent about updating that one.

clang/include/clang/Driver/Options.td

4583–4584

Can we call this "multimemory" for consistency with "multivalue" above?

[sbc100]

clang/include/clang/Driver/Options.td

4583

How about just multi_memory?

In the past we have talked about "multi-table" and "multi-memory" without using the plural here and the proposal itself is names using the singular (https://github.com/WebAssembly/multi-memory).

[sbc100]

In D158409#4603829, @tlively wrote:

The other file to update here is clang/test/Driver/wasm-features.c. It looks like we haven't been as consistent about updating that one.

Darn it, you beat be by 2 minutes.

[ashleynh]

Addressing comments
Renamed flag, test file, and added to wasm-features.c

[ashleynh]

Squashed into one commit

[aheejin]

LGTM % nit and the name resolution (multimemory vs. multi-memory)

clang/include/clang/Driver/Options.td

4583–4584

I like multi-memory more, but I preferred multi-value too when it was introduced...

llvm/lib/Target/WebAssembly/WebAssembly.td

76

Other feature descriptions are also in plain sentences, so..

[ashleynh]

removed -

[aheejin]

clang/include/clang/Driver/Options.td

4583–4584

But if we are going to remove - here, we should treat it consistently in all other places, for example, it should be not HasMultiMemory but HasMultimemory in all code. We treat multivalue that way. Do we want that?

[ashleynh]

switching back to multiple memories for description

[tlively]

clang/include/clang/Driver/Options.td

4583–4584

I prefer HasMultiMemory fwiw 😂

[ashleynh]

clang/include/clang/Driver/Options.td

4583–4584

I think multi-memory is more readable, but happy to do multimemory to fall in line with the other flags.

+1 to preferring HasMultiMemory for readability.

clang/include/clang/Driver/Options.td

 def mmultivalue : Flag<["-"], "mmultivalue">, Group<m_wasm_Features_Group>;
 def mno_multivalue : Flag<["-"], "mno-multivalue">, Group<m_wasm_Features_Group>;
 def mtail_call : Flag<["-"], "mtail-call">, Group<m_wasm_Features_Group>;
 def mno_tail_call : Flag<["-"], "mno-tail-call">, Group<m_wasm_Features_Group>;
 def mreference_types : Flag<["-"], "mreference-types">, Group<m_wasm_Features_Group>;
 def mno_reference_types : Flag<["-"], "mno-reference-types">, Group<m_wasm_Features_Group>;
 def mextended_const : Flag<["-"], "mextended-const">, Group<m_wasm_Features_Group>;
 def mno_extended_const : Flag<["-"], "mno-extended-const">, Group<m_wasm_Features_Group>;
+def mmulti_memories : Flag<["-"], "mmulti-memories">, Group<m_wasm_Features_Group>;
+def mno_multi_memories : Flag<["-"], "mno-multi-memories">, Group<m_wasm_Features_Group>;
 def mexec_model_EQ : Joined<["-"], "mexec-model=">, Group<m_wasm_Features_Driver_Group>,
                      Values<"command,reactor">,
                      HelpText<"Execution model (WebAssembly only)">,
   DocBrief<"Select between \"command\" and \"reactor\" executable models. "
            "Commands have a main-function which scopes the lifetime of the "
            "program. Reactors are activated and remain active until "
            "explicitly terminated.">;
 } // let Flags = [TargetSpecific]

clang/lib/Basic/Targets/WebAssembly.h

class LLVM_LIBRARY_VISIBILITY WebAssemblyTargetInfo : public TargetInfo {
   bool HasExceptionHandling = false;
   bool HasBulkMemory = false;
   bool HasAtomics = false;
   bool HasMutableGlobals = false;
   bool HasMultivalue = false;
   bool HasTailCall = false;
   bool HasReferenceTypes = false;
   bool HasExtendedConst = false;
+  bool HasMultiMemories = false;
 
   std::string ABI;
 
 public:
   explicit WebAssemblyTargetInfo(const llvm::Triple &T, const TargetOptions &)
       : TargetInfo(T) {
     AddrSpaceMap = &WebAssemblyAddrSpaceMap;
     NoAsmVariants = true;

clang/lib/Basic/Targets/WebAssembly.cpp

return llvm::StringSwitch<bool>(Feature)
       .Case("exception-handling", HasExceptionHandling)
       .Case("bulk-memory", HasBulkMemory)
       .Case("atomics", HasAtomics)
       .Case("mutable-globals", HasMutableGlobals)
       .Case("multivalue", HasMultivalue)
       .Case("tail-call", HasTailCall)
       .Case("reference-types", HasReferenceTypes)
       .Case("extended-const", HasExtendedConst)
+      .Case("multi-memories", HasMultiMemories)
       .Default(false);
 }
 
 bool WebAssemblyTargetInfo::isValidCPUName(StringRef Name) const {
   return llvm::is_contained(ValidCPUNames, Name);
 }
 
 void WebAssemblyTargetInfo::fillValidCPUList(
void WebAssemblyTargetInfo::getTargetDefines(const LangOptions &Opts,
   if (HasMultivalue)
     Builder.defineMacro("__wasm_multivalue__");
   if (HasTailCall)
     Builder.defineMacro("__wasm_tail_call__");
   if (HasReferenceTypes)
     Builder.defineMacro("__wasm_reference_types__");
   if (HasExtendedConst)
     Builder.defineMacro("__wasm_extended_const__");
+  if (HasMultiMemories)
+    Builder.defineMacro("__wasm_multi_memories__");
 
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8");
 }
 
 void WebAssemblyTargetInfo::setSIMDLevel(llvm::StringMap<bool> &Features,
bool WebAssemblyTargetInfo::initFeatureMap(
   if (CPU == "bleeding-edge") {
     Features["nontrapping-fptoint"] = true;
     Features["sign-ext"] = true;
     Features["bulk-memory"] = true;
     Features["atomics"] = true;
     Features["mutable-globals"] = true;
     Features["tail-call"] = true;
     Features["reference-types"] = true;
+    Features["multi-memories"] = true;
     setSIMDLevel(Features, SIMD128, true);
   } else if (CPU == "generic") {
     Features["sign-ext"] = true;
     Features["mutable-globals"] = true;
   }
 
   return TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec);
 }
for (const auto &Feature : Features) {
     if (Feature == "+extended-const") {
       HasExtendedConst = true;
       continue;
     }
     if (Feature == "-extended-const") {
       HasExtendedConst = false;
       continue;
     }
+    if (Feature == "+multi-memories") {
+      HasMultiMemories = true;
+      continue;
+    }
+    if (Feature == "-multi-memories") {
+      HasMultiMemories = false;
+      continue;
+    }
 
     Diags.Report(diag::err_opt_not_valid_with_opt)
         << Feature << "-target-feature";
     return false;
   }
   return true;
 }
 

clang/test/Preprocessor/wasm-target-features.c

 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mextended-const \
 // RUN:   | FileCheck %s -check-prefix=EXTENDED-CONST
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm64-unknown-unknown -mextended-const \
 // RUN:   | FileCheck %s -check-prefix=EXTENDED-CONST
 //
 // EXTENDED-CONST:#define __wasm_extended_const__ 1{{$}}
+//
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm32-unknown-unknown -mmulti-memories \
+// RUN:   | FileCheck %s -check-prefix=MULTI-MEMORIES
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm64-unknown-unknown -mmulti-memories \
+// RUN:   | FileCheck %s -check-prefix=MULTI-MEMORIES
+//
+// MULTI-MEMORIES:#define __wasm_multi_memories__ 1{{$}}
+//
 
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mcpu=mvp \
 // RUN:   | FileCheck %s -check-prefix=MVP
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm64-unknown-unknown -mcpu=mvp \
 // RUN:   | FileCheck %s -check-prefix=MVP
 //
 // MVP-NOT:#define __wasm_simd128__
 // MVP-NOT:#define __wasm_nontrapping_fptoint__
 // MVP-NOT:#define __wasm_sign_ext__
 // MVP-NOT:#define __wasm_exception_handling__
 // MVP-NOT:#define __wasm_bulk_memory__
 // MVP-NOT:#define __wasm_atomics__
 // MVP-NOT:#define __wasm_mutable_globals__
 // MVP-NOT:#define __wasm_multivalue__
 // MVP-NOT:#define __wasm_tail_call__
 // MVP-NOT:#define __wasm_reference_types__
 // MVP-NOT:#define __wasm_extended_const__
+// MVP-NOT:#define __wasm_multi_memories__
 
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mcpu=bleeding-edge \
 // RUN:   | FileCheck %s -check-prefix=BLEEDING-EDGE
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm64-unknown-unknown -mcpu=bleeding-edge \
 // RUN:   | FileCheck %s -check-prefix=BLEEDING-EDGE
 //
 // BLEEDING-EDGE-DAG:#define __wasm_nontrapping_fptoint__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_sign_ext__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_bulk_memory__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_simd128__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_atomics__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_mutable_globals__ 1{{$}}
 // BLEEDING-EDGE-DAG:#define __wasm_tail_call__ 1{{$}}
+// BLEEDING-EDGE-DAG:#define __wasm_multi_memories__ 1{{$}}
 // BLEEDING-EDGE-NOT:#define __wasm_unimplemented_simd128__ 1{{$}}
 // BLEEDING-EDGE-NOT:#define __wasm_exception_handling__ 1{{$}}
 // BLEEDING-EDGE-NOT:#define __wasm_multivalue__ 1{{$}}
 // BLEEDING-EDGE-NOT:#define __wasm_reference_types__ 1{{$}}
 // BLEEDING-EDGE-NOT:#define __wasm_extended_const__ 1{{$}}
 
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mcpu=bleeding-edge -mno-simd128 \
 // RUN:   | FileCheck %s -check-prefix=BLEEDING-EDGE-NO-SIMD128
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm64-unknown-unknown -mcpu=bleeding-edge -mno-simd128 \
 // RUN:   | FileCheck %s -check-prefix=BLEEDING-EDGE-NO-SIMD128
 //
 // BLEEDING-EDGE-NO-SIMD128-NOT:#define __wasm_simd128__

llvm/lib/Target/WebAssembly/WebAssembly.td

 def FeatureReferenceTypes :
       SubtargetFeature<"reference-types", "HasReferenceTypes", "true",
                        "Enable reference types">;
 
 def FeatureExtendedConst :
       SubtargetFeature<"extended-const", "HasExtendedConst", "true",
                        "Enable extended const expressions">;
 
+def FeatureMultiMemories :
+      SubtargetFeature<"multi-memories", "HasMultiMemories", "true",
+                       "Enable multiple memories">;
+
 //===----------------------------------------------------------------------===//
 // Architectures.
 //===----------------------------------------------------------------------===//
 
 //===----------------------------------------------------------------------===//
 // Register File Description
 //===----------------------------------------------------------------------===//
 

llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td

 def HasReferenceTypes :
     Predicate<"Subtarget->hasReferenceTypes()">,
     AssemblerPredicate<(all_of FeatureReferenceTypes), "reference-types">;
 
 def HasExtendedConst :
     Predicate<"Subtarget->hasExtendedConst()">,
     AssemblerPredicate<(all_of FeatureExtendedConst), "extended-const">;
 
+def HasMultiMemories :
+    Predicate<"Subtarget->hasMultiMemories()">,
+    AssemblerPredicate<(all_of FeatureMultiMemories), "multi-memories">;
+
 //===----------------------------------------------------------------------===//
 // WebAssembly-specific DAG Node Types.
 //===----------------------------------------------------------------------===//
 
 def SDT_WebAssemblyCallSeqStart : SDCallSeqStart<[SDTCisVT<0, iPTR>,
                                                   SDTCisVT<1, iPTR>]>;
 def SDT_WebAssemblyCallSeqEnd :
     SDCallSeqEnd<[SDTCisVT<0, iPTR>, SDTCisVT<1, iPTR>]>;

llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h

class WebAssemblySubtarget final : public WebAssemblyGenSubtargetInfo {
   bool HasSignExt = false;
   bool HasExceptionHandling = false;
   bool HasBulkMemory = false;
   bool HasMultivalue = false;
   bool HasMutableGlobals = false;
   bool HasTailCall = false;
   bool HasReferenceTypes = false;
   bool HasExtendedConst = false;
+  bool HasMultiMemories = false;
 
   /// What processor and OS we're targeting.
   Triple TargetTriple;
 
   WebAssemblyFrameLowering FrameLowering;
   WebAssemblyInstrInfo InstrInfo;
   WebAssemblySelectionDAGInfo TSInfo;
   WebAssemblyTargetLowering TLInfo;
public:
   bool hasNontrappingFPToInt() const { return HasNontrappingFPToInt; }
   bool hasSignExt() const { return HasSignExt; }
   bool hasExceptionHandling() const { return HasExceptionHandling; }
   bool hasBulkMemory() const { return HasBulkMemory; }
   bool hasMultivalue() const { return HasMultivalue; }
   bool hasMutableGlobals() const { return HasMutableGlobals; }
   bool hasTailCall() const { return HasTailCall; }
   bool hasReferenceTypes() const { return HasReferenceTypes; }
+  bool hasMultiMemories() const { return HasMultiMemories; }
 
   /// Parses features string setting specified subtarget options. Definition of
   /// function is auto generated by tblgen.
   void ParseSubtargetFeatures(StringRef CPU, StringRef TuneCPU, StringRef FS);
 };
 
 } // end namespace llvm
 
 #endif

llvm/test/CodeGen/WebAssembly/mutable-memories.ll

+; RUN: llc < %s -mcpu=mvp -mattr=+multi-memories | FileCheck %s
+
+; Test that multiple memories is properly emitted into the target features section
+
+target triple = "wasm32-unknown-unknown"
+
+define void @foo() {
+  ret void
+}
+
+; CHECK-LABEL: .custom_section.target_features
+; CHECK-NEXT: .int8 1
+; CHECK-NEXT: .int8 43
+; CHECK-NEXT: .int8 14
+; CHECK-NEXT: .ascii "multi-memories"