[WebAssembly] Add except_ref as a first-class type

Summary: Add except_ref as a first-class type, according to the [[https://github.com/WebAssembly/exception-handling/blob/master/proposals/Level-1.md | Level 1 exception handling proposal ]].

Reviewers: dschuff

Subscribers: jfb, sbc100, llvm-commits

Differential Revision: https://reviews.llvm.org/D43706

llvm-svn: 326985

llvm/include/llvm/BinaryFormat/Wasm.h

@@ -185,6 +185,7 @@ enum : unsigned {
   WASM_TYPE_F32 = 0x7D,
   WASM_TYPE_F64 = 0x7C,
   WASM_TYPE_ANYFUNC = 0x70,
+  WASM_TYPE_EXCEPT_REF = 0x68,
   WASM_TYPE_FUNC = 0x60,
   WASM_TYPE_NORESULT = 0x40, // for blocks with no result values
 };
@@ -217,6 +218,7 @@ enum class ValType {
   I64 = WASM_TYPE_I64,
   F32 = WASM_TYPE_F32,
   F64 = WASM_TYPE_F64,
+  EXCEPT_REF = WASM_TYPE_EXCEPT_REF,
 };
 
 // Kind codes used in the custom "name" section

llvm/include/llvm/CodeGen/MachineValueType.h

@@ -191,8 +191,10 @@ namespace llvm {
                                // unspecified type.  The register class
                                // will be determined by the opcode.
 
+      ExceptRef      = 113,    // WebAssembly's except_ref type
+
       FIRST_VALUETYPE = 1,     // This is always the beginning of the list.
-      LAST_VALUETYPE =  113,   // This always remains at the end of the list.
+      LAST_VALUETYPE =  114,   // This always remains at the end of the list.
 
       // This is the current maximum for LAST_VALUETYPE.
       // MVT::MAX_ALLOWED_VALUETYPE is used for asserts and to size bit vectors
@@ -746,6 +748,7 @@ namespace llvm {
       case v64i32:
       case v32i64:
       case nxv32i64: return 2048;
+      case ExceptRef: return 0; // opaque type
       }
     }
 

llvm/include/llvm/CodeGen/ValueTypes.td

@@ -145,6 +145,7 @@ def x86mmx : ValueType<64 , 109>;   // X86 MMX value
 def FlagVT : ValueType<0  , 110>;   // Pre-RA sched glue
 def isVoid : ValueType<0  , 111>;   // Produces no value
 def untyped: ValueType<8  , 112>;   // Produces an untyped value
+def ExceptRef: ValueType<0, 113>;   // WebAssembly's except_ref type
 def token  : ValueType<0  , 248>;   // TokenTy
 def MetadataVT: ValueType<0, 249>;  // Metadata
 

llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp

@@ -220,6 +220,7 @@ WebAssemblyInstPrinter::printWebAssemblySignatureOperand(const MCInst *MI,
   case WebAssembly::ExprType::B8x16: O << "b8x16"; break;
   case WebAssembly::ExprType::B16x8: O << "b16x8"; break;
   case WebAssembly::ExprType::B32x4: O << "b32x4"; break;
+  case WebAssembly::ExprType::ExceptRef: O << "except_ref"; break;
   }
 }
 
@@ -238,6 +239,8 @@ const char *llvm::WebAssembly::TypeToString(MVT Ty) {
   case MVT::v4i32:
   case MVT::v4f32:
     return "v128";
+  case MVT::ExceptRef:
+    return "except_ref";
   default:
     llvm_unreachable("unsupported type");
   }
@@ -253,6 +256,8 @@ const char *llvm::WebAssembly::TypeToString(wasm::ValType Type) {
     return "f32";
   case wasm::ValType::F64:
     return "f64";
+  case wasm::ValType::EXCEPT_REF:
+    return "except_ref";
   }
   llvm_unreachable("unsupported type");
 }

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp

@@ -135,6 +135,7 @@ wasm::ValType WebAssembly::toValType(const MVT &Ty) {
   case MVT::i64: return wasm::ValType::I64;
   case MVT::f32: return wasm::ValType::F32;
   case MVT::f64: return wasm::ValType::F64;
+  case MVT::ExceptRef: return wasm::ValType::EXCEPT_REF;
   default: llvm_unreachable("unexpected type");
   }
 }

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h

@@ -159,18 +159,19 @@ static const unsigned StoreP2AlignOperandNo = 0;
 
 /// This is used to indicate block signatures.
 enum class ExprType : unsigned {
-  Void    = 0x40,
+  Void      = 0x40,
-  I32     = 0x7F,
+  I32       = 0x7F,
-  I64     = 0x7E,
+  I64       = 0x7E,
-  F32     = 0x7D,
+  F32       = 0x7D,
-  F64     = 0x7C,
+  F64       = 0x7C,
-  I8x16   = 0x7B,
+  I8x16     = 0x7B,
-  I16x8   = 0x7A,
+  I16x8     = 0x7A,
-  I32x4   = 0x79,
+  I32x4     = 0x79,
-  F32x4   = 0x78,
+  F32x4     = 0x78,
-  B8x16   = 0x77,
+  B8x16     = 0x77,
-  B16x8   = 0x76,
+  B16x8     = 0x76,
-  B32x4   = 0x75
+  B32x4     = 0x75,
+  ExceptRef = 0x68
 };
 
 /// Instruction opcodes emitted via means other than CodeGen.

llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp

@@ -249,6 +249,7 @@ static void FixEndsAtEndOfFunction(
   case MVT::v8i16: retType = WebAssembly::ExprType::I16x8; break;
   case MVT::v4i32: retType = WebAssembly::ExprType::I32x4; break;
   case MVT::v4f32: retType = WebAssembly::ExprType::F32x4; break;
+  case MVT::ExceptRef: retType = WebAssembly::ExprType::ExceptRef; break;
   default: llvm_unreachable("unexpected return type");
   }
 

llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp

@@ -86,6 +86,8 @@ static unsigned getDropOpcode(const TargetRegisterClass *RC) {
     return WebAssembly::DROP_F64;
   if (RC == &WebAssembly::V128RegClass)
     return WebAssembly::DROP_V128;
+  if (RC == &WebAssembly::EXCEPT_REFRegClass)
+    return WebAssembly::DROP_EXCEPT_REF;
   llvm_unreachable("Unexpected register class");
 }
 
@@ -101,6 +103,8 @@ static unsigned getGetLocalOpcode(const TargetRegisterClass *RC) {
     return WebAssembly::GET_LOCAL_F64;
   if (RC == &WebAssembly::V128RegClass)
     return WebAssembly::GET_LOCAL_V128;
+  if (RC == &WebAssembly::EXCEPT_REFRegClass)
+    return WebAssembly::GET_LOCAL_EXCEPT_REF;
   llvm_unreachable("Unexpected register class");
 }
 
@@ -116,6 +120,8 @@ static unsigned getSetLocalOpcode(const TargetRegisterClass *RC) {
     return WebAssembly::SET_LOCAL_F64;
   if (RC == &WebAssembly::V128RegClass)
     return WebAssembly::SET_LOCAL_V128;
+  if (RC == &WebAssembly::EXCEPT_REFRegClass)
+    return WebAssembly::SET_LOCAL_EXCEPT_REF;
   llvm_unreachable("Unexpected register class");
 }
 
@@ -131,6 +137,8 @@ static unsigned getTeeLocalOpcode(const TargetRegisterClass *RC) {
     return WebAssembly::TEE_LOCAL_F64;
   if (RC == &WebAssembly::V128RegClass)
     return WebAssembly::TEE_LOCAL_V128;
+  if (RC == &WebAssembly::EXCEPT_REFRegClass)
+    return WebAssembly::TEE_LOCAL_EXCEPT_REF;
   llvm_unreachable("Unexpected register class");
 }
 
@@ -144,6 +152,8 @@ static MVT typeForRegClass(const TargetRegisterClass *RC) {
     return MVT::f32;
   if (RC == &WebAssembly::F64RegClass)
     return MVT::f64;
+  if (RC == &WebAssembly::EXCEPT_REFRegClass)
+    return MVT::ExceptRef;
   llvm_unreachable("unrecognized register class");
 }
 

llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -127,6 +127,7 @@ private:
     case MVT::i64:
     case MVT::f32:
     case MVT::f64:
+    case MVT::ExceptRef:
       return VT;
     case MVT::f16:
       return MVT::f32;
@@ -681,6 +682,10 @@ bool WebAssemblyFastISel::fastLowerArguments() {
       Opc = WebAssembly::ARGUMENT_v4f32;
       RC = &WebAssembly::V128RegClass;
       break;
+    case MVT::ExceptRef:
+      Opc = WebAssembly::ARGUMENT_EXCEPT_REF;
+      RC = &WebAssembly::EXCEPT_REFRegClass;
+      break;
     default:
       return false;
     }
@@ -770,6 +775,11 @@ bool WebAssemblyFastISel::selectCall(const Instruction *I) {
           IsDirect ? WebAssembly::CALL_v4f32 : WebAssembly::PCALL_INDIRECT_v4f32;
       ResultReg = createResultReg(&WebAssembly::V128RegClass);
       break;
+    case MVT::ExceptRef:
+      Opc = IsDirect ? WebAssembly::CALL_EXCEPT_REF
+                     : WebAssembly::PCALL_INDIRECT_EXCEPT_REF;
+      ResultReg = createResultReg(&WebAssembly::EXCEPT_REFRegClass);
+      break;
     default:
       return false;
     }
@@ -868,6 +878,10 @@ bool WebAssemblyFastISel::selectSelect(const Instruction *I) {
     Opc = WebAssembly::SELECT_F64;
     RC = &WebAssembly::F64RegClass;
     break;
+  case MVT::ExceptRef:
+    Opc = WebAssembly::SELECT_EXCEPT_REF;
+    RC = &WebAssembly::EXCEPT_REFRegClass;
+    break;
   default:
     return false;
   }
@@ -1274,6 +1288,9 @@ bool WebAssemblyFastISel::selectRet(const Instruction *I) {
   case MVT::v4f32:
     Opc = WebAssembly::RETURN_v4f32;
     break;
+  case MVT::ExceptRef:
+    Opc = WebAssembly::RETURN_EXCEPT_REF;
+    break;
   default: return false;
   }
 

llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td

@@ -72,6 +72,7 @@ let Uses = [SP32, SP64], isCall = 1 in {
   defm : CALL<I64, "i64.">;
   defm : CALL<F32, "f32.">;
   defm : CALL<F64, "f64.">;
+  defm : CALL<EXCEPT_REF, "except_ref.">;
   defm : SIMD_CALL<v16i8, "i8x16.">;
   defm : SIMD_CALL<v8i16, "i16x8.">;
   defm : SIMD_CALL<v4i32, "i32x4.">;
@@ -112,6 +113,9 @@ def : Pat<(v4i32 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
           (CALL_v4i32 tglobaladdr:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(v4f32 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
           (CALL_v4f32 tglobaladdr:$callee)>, Requires<[HasSIMD128]>;
+def : Pat<(ExceptRef
+           (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
+          (CALL_EXCEPT_REF tglobaladdr:$callee)>;
 def : Pat<(WebAssemblycall0 (WebAssemblywrapper tglobaladdr:$callee)),
           (CALL_VOID tglobaladdr:$callee)>;
 
@@ -132,5 +136,8 @@ def : Pat<(v4i32 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
           (CALL_v4i32 texternalsym:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(v4f32 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
           (CALL_v4f32 texternalsym:$callee)>, Requires<[HasSIMD128]>;
+def : Pat<(ExceptRef
+           (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
+          (CALL_EXCEPT_REF texternalsym:$callee)>;
 def : Pat<(WebAssemblycall0 (WebAssemblywrapper texternalsym:$callee)),
           (CALL_VOID texternalsym:$callee)>;

llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td

@@ -98,6 +98,7 @@ let isReturn = 1 in {
   defm : RETURN<I64>;
   defm : RETURN<F32>;
   defm : RETURN<F64>;
+  defm : RETURN<EXCEPT_REF>;
   defm : SIMD_RETURN<v16i8>;
   defm : SIMD_RETURN<v8i16>;
   defm : SIMD_RETURN<v4i32>;

llvm/lib/Target/WebAssembly/WebAssemblyInstrExceptRef.td

@@ -0,0 +1,29 @@
+// WebAssemblyInstrExceptRef.td-WebAssembly except_ref codegen --*- tablegen -*-
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief WebAssembly except_ref operand code-gen constructs.
+///
+//===----------------------------------------------------------------------===//
+
+let Defs = [ARGUMENTS] in {
+
+def SELECT_EXCEPT_REF : I<(outs EXCEPT_REF:$dst),
+                          (ins EXCEPT_REF:$lhs, EXCEPT_REF:$rhs, I32:$cond),
+                          [(set EXCEPT_REF:$dst,
+                           (select I32:$cond, EXCEPT_REF:$lhs,
+                            EXCEPT_REF:$rhs))],
+                          "except_ref.select\t$dst, $lhs, $rhs, $cond", 0x1b>;
+
+} // Defs = [ARGUMENTS]
+
+def : Pat<(select (i32 (setne I32:$cond, 0)), EXCEPT_REF:$lhs, EXCEPT_REF:$rhs),
+          (SELECT_EXCEPT_REF EXCEPT_REF:$lhs, EXCEPT_REF:$rhs, I32:$cond)>;
+def : Pat<(select (i32 (seteq I32:$cond, 0)), EXCEPT_REF:$lhs, EXCEPT_REF:$rhs),
+          (SELECT_EXCEPT_REF EXCEPT_REF:$rhs, EXCEPT_REF:$lhs, I32:$cond)>;

llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td

@@ -166,6 +166,7 @@ defm : ARGUMENT<I32>;
 defm : ARGUMENT<I64>;
 defm : ARGUMENT<F32>;
 defm : ARGUMENT<F64>;
+defm : ARGUMENT<EXCEPT_REF>;
 defm : SIMD_ARGUMENT<v16i8>;
 defm : SIMD_ARGUMENT<v8i16>;
 defm : SIMD_ARGUMENT<v4i32>;
@@ -232,6 +233,7 @@ defm : LOCAL<I64>;
 defm : LOCAL<F32>;
 defm : LOCAL<F64>;
 defm : LOCAL<V128>, Requires<[HasSIMD128]>;
+defm : LOCAL<EXCEPT_REF>, Requires<[HasExceptionHandling]>;
 
 let isMoveImm = 1, isAsCheapAsAMove = 1, isReMaterializable = 1 in {
 def CONST_I32 : I<(outs I32:$res), (ins i32imm_op:$imm),
@@ -267,3 +269,4 @@ include "WebAssemblyInstrConv.td"
 include "WebAssemblyInstrFloat.td"
 include "WebAssemblyInstrAtomics.td"
 include "WebAssemblyInstrSIMD.td"
+include "WebAssemblyInstrExceptRef.td"

llvm/lib/Target/WebAssembly/WebAssemblyRegisterInfo.td

@@ -38,8 +38,8 @@ def SP64 : WebAssemblyReg<"%SP64">;
 // since we otherwise don't need a physical register in those classes.
 def F32_0 : WebAssemblyReg<"%f32.0">;
 def F64_0 : WebAssemblyReg<"%f64.0">;
-
 def V128_0: WebAssemblyReg<"%v128">;
+def EXCEPT_REF_0 : WebAssemblyReg<"%except_ref.0">;
 
 // The value stack "register". This is an opaque entity which serves to order
 // uses and defs that must remain in LIFO order.
@@ -59,4 +59,4 @@ def I64 : WebAssemblyRegClass<[i64], 64, (add FP64, SP64)>;
 def F32 : WebAssemblyRegClass<[f32], 32, (add F32_0)>;
 def F64 : WebAssemblyRegClass<[f64], 64, (add F64_0)>;
 def V128 : WebAssemblyRegClass<[v4f32, v4i32, v16i8, v8i16], 128, (add V128_0)>;
-
+def EXCEPT_REF : WebAssemblyRegClass<[ExceptRef], 0, (add EXCEPT_REF_0)>;

llvm/utils/TableGen/CodeGenTarget.cpp

@@ -174,6 +174,7 @@ StringRef llvm::getEnumName(MVT::SimpleValueType T) {
   case MVT::iPTR:     return "MVT::iPTR";
   case MVT::iPTRAny:  return "MVT::iPTRAny";
   case MVT::Untyped:  return "MVT::Untyped";
+  case MVT::ExceptRef: return "MVT::ExceptRef";
   default: llvm_unreachable("ILLEGAL VALUE TYPE!");
   }
 }