[clang][Webassembly] Implement builtins for tables

[asb]

Summary

Implements table.size, table.grow, table.fill and table.copy.

table.init and elem.drop are intentionally not implemented because they require manipulation of element segments, which aren't directly exposed in the current WebAssembly Clang/LLVM toolchain.

This is ready for a first-pass review, though will need an update for coverage of funcref tables once D122215 funcrefs are finalised.

[sbc100]

clang/include/clang/AST/Type.h

1912 ↗

(On Diff #424166)

Can you explain the distinction here? Maybe a comment would be good?

[asb]

clang/include/clang/AST/Type.h

1912 ↗

(On Diff #424166)

Sorry for the confusion - this particular change makes less sense in the absence of funcref support. We need to differentiate between extenref and funcref types in order to choose the appropriate intrinsic for those which are type-dependent (table.grow and table.fill). I'll revisit documentation comments etc when adding in funcref support.

[asb]

Rebase.

[asb]

Rebase and fix missing CHECK lines for table copy.

[asb]

Rebase (partial - rebases my patch stack on top of latest LLVM, but still needs a rebase on to Paulo's patch introducing funcref support).

[asb]

Rebase.

[asb]

Rebase again.

[pmatos]

@asb This can be closed since table support landed.

[asb]

Abandoning as this was superseded by @pmatos' patch that incorported this and other work.

clang/include/clang/Basic/BuiltinsWebAssembly.def

 // Reference Types builtins
 // Some builtins are polymorphic - see 't' as part of the third argument,
 // in which case the argument spec (second argument) is unused.
 TARGET_BUILTIN(__builtin_wasm_ref_null_extern, "e", "nc", "reference-types")
 // A funcref represented as a function pointer with the funcref attribute
 // attached to the type, therefore SemaChecking will check for the right
 // return type.
 TARGET_BUILTIN(__builtin_wasm_ref_null_func, "i", "nct", "reference-types")
+
+// Table builtins
+TARGET_BUILTIN(__builtin_wasm_table_size, "ii", "nt", "reference-types")
+TARGET_BUILTIN(__builtin_wasm_table_grow, "iiii", "nt", "reference-types")
+TARGET_BUILTIN(__builtin_wasm_table_fill, "viiii", "t", "reference-types")
+TARGET_BUILTIN(__builtin_wasm_table_copy, "viiiii", "t", "reference-types")
+
 #undef BUILTIN
 #undef TARGET_BUILTIN

clang/include/clang/Basic/DiagnosticSemaKinds.td

 def err_wasm_table_catch : Error<
   "cannot catch WebAssembly table">;
 def err_wasm_table_exception_spec : Error<
   "WebAssembly table not allowed in exception sepcification">;
 def err_wasm_table_must_be_static : Error<
   "WebAssembly table must be static">;
 def err_wasm_multidimensional_ref_array : Error<
   "multi-dimensional arrays of WebAssembly references are illegal">;
+def err_wasm_builtin_arg_must_be_table_type : Error <
+  "%ordinal0 argument must be a WebAssembly table">;
+def err_wasm_builtin_arg_must_match_table_element_type : Error <
+  "%ordinal0 argument must match the element type of the WebAssembly table in the %ordinal1 argument">;
+def err_wasm_builtin_arg_must_be_integer_type : Error <
+  "%ordinal0 argument must be an integer">;
 } // end of sema component.

clang/include/clang/Sema/Sema.h

ExprResult SemaBuiltinMatrixTranspose(CallExpr *TheCall,
                                         ExprResult CallResult);
   ExprResult SemaBuiltinMatrixColumnMajorLoad(CallExpr *TheCall,
                                               ExprResult CallResult);
   ExprResult SemaBuiltinMatrixColumnMajorStore(CallExpr *TheCall,
                                                ExprResult CallResult);
 
   // WebAssembly builtin handling
   bool SemaBuiltinWasmRefNullFunc(CallExpr *TheCall);
+  bool SemaBuiltinWasmTableSize(CallExpr *TheCall);
+  bool SemaBuiltinWasmTableGrow(CallExpr *TheCall);
+  bool SemaBuiltinWasmTableFill(CallExpr *TheCall);
+  bool SemaBuiltinWasmTableCopy(CallExpr *TheCall);
 
 public:
   enum FormatStringType {
     FST_Scanf,
     FST_Printf,
     FST_NSString,
     FST_Strftime,
     FST_Strfmon,

clang/lib/CodeGen/CGBuiltin.cpp

Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
   case WebAssembly::BI__builtin_wasm_dot_i8x16_i7x16_add_s_i32x4: {
     Value *LHS = EmitScalarExpr(E->getArg(0));
     Value *RHS = EmitScalarExpr(E->getArg(1));
     Value *Acc = EmitScalarExpr(E->getArg(2));
     Function *Callee =
         CGM.getIntrinsic(Intrinsic::wasm_dot_i8x16_i7x16_add_signed);
     return Builder.CreateCall(Callee, {LHS, RHS, Acc});
   }
+  case WebAssembly::BI__builtin_wasm_table_size: {
+    assert(E->getArg(0)->getType()->isArrayType());
+    Value *Value =
+        EmitCastToVoidPtr(EmitArrayToPointerDecay(E->getArg(0)).getPointer());
+    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_table_size);
+    return Builder.CreateCall(Callee, Value);
+  }
+  case WebAssembly::BI__builtin_wasm_table_grow: {
+    assert(E->getArg(0)->getType()->isArrayType());
+    Value *Table =
+        EmitCastToVoidPtr(EmitArrayToPointerDecay(E->getArg(0)).getPointer());
+    Value *Val = EmitScalarExpr(E->getArg(1));
+    Value *NElems = EmitScalarExpr(E->getArg(2));
+
+    Function *Callee;
+    if (E->getArg(1)->getType()->isWebAssemblyExternrefType())
+      Callee = CGM.getIntrinsic(Intrinsic::wasm_table_grow_externref);
+    else
+      llvm_unreachable(
+          "Unexpected reference type for __builtin_wasm_table_grow");
+
+    return Builder.CreateCall(Callee, {Table, Val, NElems});
+  }
+  case WebAssembly::BI__builtin_wasm_table_fill: {
+    assert(E->getArg(0)->getType()->isArrayType());
+    Value *Table =
+        EmitCastToVoidPtr(EmitArrayToPointerDecay(E->getArg(0)).getPointer());
+    Value *Index = EmitScalarExpr(E->getArg(1));
+    Value *Val = EmitScalarExpr(E->getArg(2));
+    Value *NElems = EmitScalarExpr(E->getArg(3));
+
+    Function *Callee;
+    if (E->getArg(2)->getType()->isWebAssemblyExternrefType())
+      Callee = CGM.getIntrinsic(Intrinsic::wasm_table_fill_externref);
+    else
+      llvm_unreachable(
+          "Unexpected reference type for __builtin_wasm_table_fill");
+
+    return Builder.CreateCall(Callee, {Table, Index, Val, NElems});
+  }
+  case WebAssembly::BI__builtin_wasm_table_copy: {
+    assert(E->getArg(0)->getType()->isArrayType());
+    Value *TableX =
+        EmitCastToVoidPtr(EmitArrayToPointerDecay(E->getArg(0)).getPointer());
+    Value *TableY =
+        EmitCastToVoidPtr(EmitArrayToPointerDecay(E->getArg(1)).getPointer());
+    Value *DstIdx = EmitScalarExpr(E->getArg(2));
+    Value *SrcIdx = EmitScalarExpr(E->getArg(3));
+    Value *NElems = EmitScalarExpr(E->getArg(4));
+
+    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_table_copy);
+
+    return Builder.CreateCall(Callee, {TableX, TableY, SrcIdx, DstIdx, NElems});
+  }
   default:
     return nullptr;
   }
 }
 
 static std::pair<Intrinsic::ID, unsigned>
 getIntrinsicForHexagonNonClangBuiltin(unsigned BuiltinID) {
   struct Info {

clang/lib/Sema/SemaChecking.cpp

 }
 
 bool Sema::CheckWebAssemblyBuiltinFunctionCall(const TargetInfo &TI,
                                                unsigned BuiltinID,
                                                CallExpr *TheCall) {
   switch (BuiltinID) {
   case WebAssembly::BI__builtin_wasm_ref_null_func:
     return (SemaBuiltinWasmRefNullFunc(TheCall));
+  case WebAssembly::BI__builtin_wasm_table_size:
+    return SemaBuiltinWasmTableSize(TheCall);
+  case WebAssembly::BI__builtin_wasm_table_grow:
+    return SemaBuiltinWasmTableGrow(TheCall);
+  case WebAssembly::BI__builtin_wasm_table_fill:
+    return SemaBuiltinWasmTableFill(TheCall);
+  case WebAssembly::BI__builtin_wasm_table_copy:
+    return SemaBuiltinWasmTableCopy(TheCall);
   }
 
   return false;
 }
 
 /// SemaBuiltinCpuSupports - Handle __builtin_cpu_supports(char *).
 /// This checks that the target supports __builtin_cpu_supports and
 /// that the string argument is constant and valid.
ExprResult Sema::SemaBuiltinMatrixColumnMajorStore(CallExpr *TheCall,
   }
 
   if (ArgError)
     return ExprError();
 
   return CallResult;
 }
 
+/// Checks the argument at the given index is a WebAssembly table and if it
+/// is, sets ElTy to the element type.
+static bool CheckWasmBuiltinArgIsTable(Sema &S, CallExpr *E, unsigned ArgIndex,
+                                       const Type *&ElTy) {
+  Expr *ArgExpr = E->getArg(ArgIndex);
+  ElTy = ArgExpr->getType()->getArrayElementTypeNoTypeQual();
+  if (!ElTy || !ElTy->isWebAssemblyReferenceType()) {
+    return S.Diag(ArgExpr->getBeginLoc(),
+                  diag::err_wasm_builtin_arg_must_be_table_type)
+           << ArgIndex + 1 << ArgExpr->getSourceRange();
+  }
+  return false;
+}
+
+/// Checks the argument at the given index is an integer.
+static bool CheckWasmBuiltinArgIsInteger(Sema &S, CallExpr *E,
+                                         unsigned ArgIndex) {
+  Expr *ArgExpr = E->getArg(ArgIndex);
+  if (!ArgExpr->getType()->isIntegerType()) {
+    return S.Diag(ArgExpr->getBeginLoc(),
+                  diag::err_wasm_builtin_arg_must_be_integer_type)
+           << ArgIndex + 1 << ArgExpr->getSourceRange();
+  }
+  return false;
+}
+
+/// Check that the argument is a WebAssembly table.
+bool Sema::SemaBuiltinWasmTableSize(CallExpr *TheCall) {
+  if (checkArgCount(*this, TheCall, 1))
+    return true;
+
+  const Type *ElTy;
+  if (CheckWasmBuiltinArgIsTable(*this, TheCall, 0, ElTy))
+    return true;
+
+  return false;
+}
+
+/// Check that the first argument is a WebAssembly table, the second is the
+/// value to use for new elements (of a type matching the table type), the
+/// third value is an integer.
+bool Sema::SemaBuiltinWasmTableGrow(CallExpr *TheCall) {
+  if (checkArgCount(*this, TheCall, 3))
+    return true;
+
+  const Type *ElTy;
+  if (CheckWasmBuiltinArgIsTable(*this, TheCall, 0, ElTy))
+    return true;
+
+  Expr *NewElemArg = TheCall->getArg(1);
+  if (!Context.hasSameType(ElTy, NewElemArg->getType().getTypePtr())) {
+    return Diag(NewElemArg->getBeginLoc(),
+                diag::err_wasm_builtin_arg_must_match_table_element_type)
+           << 2 << 1 << NewElemArg->getSourceRange();
+  }
+
+  if (CheckWasmBuiltinArgIsInteger(*this, TheCall, 2))
+    return true;
+
+  return false;
+}
+
+/// Check that the first argument is a WebAssembly table, the second is an
+/// integer, the third is the value to use to fill the table (of a type
+/// matching the table type), and the fourth is an integer.
+bool Sema::SemaBuiltinWasmTableFill(CallExpr *TheCall) {
+  if (checkArgCount(*this, TheCall, 4))
+    return true;
+
+  const Type *ElTy;
+  if (CheckWasmBuiltinArgIsTable(*this, TheCall, 0, ElTy))
+    return true;
+
+  if (CheckWasmBuiltinArgIsInteger(*this, TheCall, 1))
+    return true;
+
+  Expr *NewElemArg = TheCall->getArg(2);
+  if (!Context.hasSameType(ElTy, NewElemArg->getType().getTypePtr())) {
+    return Diag(NewElemArg->getBeginLoc(),
+                diag::err_wasm_builtin_arg_must_match_table_element_type)
+           << 3 << 1 << NewElemArg->getSourceRange();
+  }
+
+  if (CheckWasmBuiltinArgIsInteger(*this, TheCall, 3))
+    return true;
+
+  return false;
+}
+
+/// Check that the first argument is a WebAssembly table, the second is also a
+/// WebAssembly table (of the same element type), and the third to fifth
+/// arguments are integers.
+bool Sema::SemaBuiltinWasmTableCopy(CallExpr *TheCall) {
+  if (checkArgCount(*this, TheCall, 5))
+    return true;
+
+  const Type *XElTy;
+  if (CheckWasmBuiltinArgIsTable(*this, TheCall, 0, XElTy))
+    return true;
+
+  const Type *YElTy;
+  if (CheckWasmBuiltinArgIsTable(*this, TheCall, 1, YElTy))
+    return true;
+
+  Expr *TableYArg = TheCall->getArg(1);
+  if (!Context.hasSameType(XElTy, YElTy)) {
+    return Diag(TableYArg->getBeginLoc(),
+                diag::err_wasm_builtin_arg_must_match_table_element_type)
+           << 2 << 1 << TableYArg->getSourceRange();
+  }
+
+  for (int I = 2; I <= 4; I++) {
+    if (CheckWasmBuiltinArgIsInteger(*this, TheCall, I))
+      return true;
+  }
+
+  return false;
+}
+
 /// \brief Enforce the bounds of a TCB
 /// CheckTCBEnforcement - Enforces that every function in a named TCB only
 /// directly calls other functions in the same TCB as marked by the enforce_tcb
 /// and enforce_tcb_leaf attributes.
 void Sema::CheckTCBEnforcement(const SourceLocation CallExprLoc,
                                const NamedDecl *Callee) {
   const NamedDecl *Caller = getCurFunctionOrMethodDecl();
 

clang/test/CodeGen/WebAssembly/builtins-table.c

+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature
+// RUN: %clang_cc1 -triple wasm32 -target-feature +reference-types -disable-O0-optnone -emit-llvm %s -o - | opt -S -mem2reg | FileCheck %s
+// REQUIRES: webassembly-registered-target
+
+static __externref_t table[0];
+
+// CHECK-LABEL: define {{[^@]+}}@test_builtin_wasm_table_size
+// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call i32 @llvm.wasm.table.size(ptr addrspace(1) @table)
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+int test_builtin_wasm_table_size() {
+  return __builtin_wasm_table_size(table);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@test_builtin_wasm_table_grow
+// CHECK-SAME: (ptr addrspace(10) [[REF:%.*]], i32 noundef [[NELEM:%.*]]) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call i32 @llvm.wasm.table.grow.externref(ptr addrspace(1) @table, ptr addrspace(10) [[REF]], i32 [[NELEM]])
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+int test_builtin_wasm_table_grow(__externref_t ref, int nelem) {
+  return __builtin_wasm_table_grow(table, ref, nelem);
+}
+
+// CHECK-LABEL: define {{[^@]+}}@test_builtin_wasm_table_fill
+// CHECK-SAME: (i32 noundef [[INDEX:%.*]], ptr addrspace(10) [[REF:%.*]], i32 noundef [[NELEM:%.*]]) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    call void @llvm.wasm.table.fill.externref(ptr addrspace(1) @table, i32 [[INDEX]], ptr addrspace(10) [[REF]], i32 [[NELEM]])
+// CHECK-NEXT:    ret void
+//
+void test_builtin_wasm_table_fill(int index, __externref_t ref, int nelem) {
+  __builtin_wasm_table_fill(table, index, ref, nelem);
+}
+
+static __externref_t other_table[0];
+
+// CHECK-LABEL: define {{[^@]+}}@test_table_copy
+// CHECK-SAME: (i32 noundef [[DST_IDX:%.*]], i32 noundef [[SRC_IDX:%.*]], i32 noundef [[NELEM:%.*]]) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    call void @llvm.wasm.table.copy(ptr addrspace(1) @table, ptr addrspace(1) @other_table, i32 [[SRC_IDX]], i32 [[DST_IDX]], i32 [[NELEM]])
+// CHECK-NEXT:    ret void
+//
+void test_table_copy(int dst_idx, int src_idx, int nelem) {
+  __builtin_wasm_table_copy(table, other_table, dst_idx, src_idx, nelem);
+}

clang/test/Sema/builtins-wasm.c

+// RUN: %clang_cc1 -fsyntax-only -verify -triple wasm32 -target-feature +reference-types %s
+
+static __externref_t table[0];
+
+void test_table_size(__externref_t ref, void *ptr, int arr[]) {
+  __builtin_wasm_table_size();                        // expected-error {{too few arguments to function call, expected 1, have 0}}
+  __builtin_wasm_table_size(1);                       // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_size(ref);                     // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_size(ptr);                     // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_size(arr);                     // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_size(table, table);            // expected-error {{too many arguments to function call, expected 1, have 2}}
+  void *a = __builtin_wasm_table_size(table);         // expected-warning {{incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int'}}
+  __externref_t b = __builtin_wasm_table_size(table); // expected-error {{initializing '__externref_t' with an expression of incompatible type 'int'}}
+  int c = __builtin_wasm_table_size(table);
+}
+
+void test_table_grow(__externref_t ref, int size) {
+  __builtin_wasm_table_grow();                           // expected-error {{too few arguments to function call, expected 3, have 0}}
+  __builtin_wasm_table_grow(table, table, table, table); // expected-error {{too many arguments to function call, expected 3, have 4}}
+  __builtin_wasm_table_grow(ref, ref, size);             // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_grow(table, table, size);         // expected-error {{2nd argument must match the element type of the WebAssembly table in the 1st argument}}
+  __builtin_wasm_table_grow(table, ref, table);          // expected-error {{3rd argument must be an integer}}
+  void *a = __builtin_wasm_table_grow(table, ref, size); // expected-warning {{incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int'}}
+  int b = __builtin_wasm_table_grow(table, ref, size);
+}
+
+void test_table_fill(int index, __externref_t ref, int nelem) {
+  __builtin_wasm_table_fill();                                   // expected-error {{too few arguments to function call, expected 4, have 0}}
+  __builtin_wasm_table_fill(table, table, table, table, table);  // expected-error {{too many arguments to function call, expected 4, have 5}}
+  __builtin_wasm_table_fill(index, index, ref, nelem);           // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_fill(table, table, ref, nelem);           // expected-error {{2nd argument must be an integer}}
+  __builtin_wasm_table_fill(table, index, index, ref);           // expected-error {{3rd argument must match the element type of the WebAssembly table in the 1st argument}}
+  __builtin_wasm_table_fill(table, index, ref, table);           // expected-error {{4th argument must be an integer}}
+  void *a = __builtin_wasm_table_fill(table, index, ref, nelem); // expected-error {{initializing 'void *' with an expression of incompatible type 'void'}}
+  __builtin_wasm_table_fill(table, index, ref, nelem);
+}
+
+void test_table_copy(int dst_idx, int src_idx, int nelem) {
+  __builtin_wasm_table_copy();                                         // expected-error {{too few arguments to function call, expected 5, have 0}}
+  __builtin_wasm_table_copy(table, table, table, table, table, table); // expected-error {{too many arguments to function call, expected 5, have 6}}
+  __builtin_wasm_table_copy(src_idx, table, dst_idx, src_idx, nelem);  // expected-error {{1st argument must be a WebAssembly table}}
+  __builtin_wasm_table_copy(table, src_idx, dst_idx, src_idx, nelem);  // expected-error {{2nd argument must be a WebAssembly table}}
+  __builtin_wasm_table_copy(table, table, table, src_idx, nelem);      // expected-error {{3rd argument must be an integer}}
+  __builtin_wasm_table_copy(table, table, dst_idx, table, nelem);      // expected-error {{4th argument must be an integer}}
+  __builtin_wasm_table_copy(table, table, dst_idx, src_idx, table);    // expected-error {{5th argument must be an integer}}
+  __builtin_wasm_table_copy(table, table, dst_idx, src_idx, nelem);
+}