Move type dispatch of ConvCellToInt to simplifier

Currently, CastInt does this all in its HHBC -> HHIR
translation, but this could be improved.

hphp/runtime/vm/jit/hhbctranslator.cpp

@@ -2880,26 +2880,8 @@ void HhbcTranslator::emitCastDouble() {
 void HhbcTranslator::emitCastInt() {
   IRTrace* catchTrace = getCatchTrace();
   SSATmp* src = popC();
-  Type fromType = src->type();
-  if (fromType.isInt()) {
-    push(src);
-  } else if (fromType.isNull()) {
-    push(cns(0));
-  } else if (fromType.isArray()) {
-    push(gen(ConvArrToInt, src));
-    gen(DecRef, src);
-  } else if (fromType.isBool()) {
-    push(gen(ConvBoolToInt, src));
-  } else if (fromType.isDbl()) {
-    push(gen(ConvDblToInt, src));
-  } else if (fromType.isString()) {
-    push(gen(ConvStrToInt, src));
-    gen(DecRef, src);
-  } else if (fromType.isObj()) {
-    push(gen(ConvObjToInt, catchTrace, src));
-  } else {
-    push(gen(ConvCellToInt, catchTrace, src));
-  }
+  push(gen(ConvCellToInt, catchTrace, src));
+  gen(DecRef, src);
 }
 
 void HhbcTranslator::emitCastObject() {

hphp/runtime/vm/jit/ir.h

@@ -242,9 +242,9 @@ O(ConvCellToDbl,                D(Dbl), S(Cell),                  N|Er|CRc|K) \
 O(ConvArrToInt,                 D(Int), S(Arr),                          C|N) \
 O(ConvBoolToInt,                D(Int), S(Bool),                           C) \
 O(ConvDblToInt,                 D(Int), S(Dbl),                          C|N) \
-O(ConvObjToInt,                 D(Int), S(Obj),                   N|Er|CRc|K) \
+O(ConvObjToInt,                 D(Int), S(Obj),                       N|Er|K) \
 O(ConvStrToInt,                 D(Int), S(Str),                            N) \
-O(ConvCellToInt,                D(Int), S(Cell),                  N|Er|CRc|K) \
+O(ConvCellToInt,                D(Int), S(Cell),                      N|Er|K) \
                                                                               \
 O(ConvCellToObj,                D(Obj), S(Cell),                     N|CRc|K) \
                                                                               \

hphp/runtime/vm/jit/simplifier.cpp

@@ -305,6 +305,7 @@ SSATmp* Simplifier::simplify(IRInstruction* inst) {
   case ConvDblToStr:  return simplifyConvDblToStr(inst);
   case ConvIntToStr:  return simplifyConvIntToStr(inst);
   case ConvCellToBool:return simplifyConvCellToBool(inst);
+  case ConvCellToInt: return simplifyConvCellToInt(inst);
   case Unbox:         return simplifyUnbox(inst);
   case UnboxPtr:      return simplifyUnboxPtr(inst);
   case IsType:
@@ -1446,6 +1447,21 @@ SSATmp* Simplifier::simplifyConvCellToBool(IRInstruction* inst) {
   return nullptr;
 }
 
+SSATmp* Simplifier::simplifyConvCellToInt(IRInstruction* inst) {
+  auto const src      = inst->src(0);
+  auto const srcType  = src->type();
+
+  if (srcType.isInt())    return src;
+  if (srcType.isNull())   return cns(0);
+  if (srcType.isArray())  return gen(ConvArrToInt, src);
+  if (srcType.isBool())   return gen(ConvBoolToInt, src);
+  if (srcType.isDbl())    return gen(ConvDblToInt, src);
+  if (srcType.isString()) return gen(ConvStrToInt, src);
+  if (srcType.isObj())    return gen(ConvObjToInt, inst->taken(), src);
+
+  return nullptr;
+}
+
 SSATmp* Simplifier::simplifyLdClsPropAddr(IRInstruction* inst) {
   SSATmp* propName = inst->src(1);
   if (!propName->isConst()) return nullptr;

hphp/runtime/vm/jit/simplifier.h

@@ -101,6 +101,7 @@ private:
   SSATmp* simplifyConvDblToStr(IRInstruction*);
   SSATmp* simplifyConvIntToStr(IRInstruction*);
   SSATmp* simplifyConvCellToBool(IRInstruction*);
+  SSATmp* simplifyConvCellToInt(IRInstruction*);
   SSATmp* simplifyUnbox(IRInstruction*);
   SSATmp* simplifyUnboxPtr(IRInstruction*);
   SSATmp* simplifyCheckInit(IRInstruction* inst);

hphp/runtime/vm/jit/translator-runtime.cpp

@@ -170,19 +170,7 @@ int64_t convStrToIntHelper(const StringData* s) {
 }
 
 int64_t convCellToIntHelper(TypedValue tv) {
-  try {
-    tvCastToInt64InPlace(&tv); // consumes a ref on counted values
-                               // but not if an exception happens. (REVIEW)
-    return tv.m_data.num;
-  } catch (...) {
-    // spill tv back to stack. unwinder
-    // will take care of decreffing it.
-    VMRegAnchor _;
-    TypedValue* spillSlot = (TypedValue *)vmsp();
-    spillSlot->m_data.num = tv.m_data.num;
-    spillSlot->m_type = tv.m_type;
-    throw;
-  }
+  return tvCastToInt64(&tv);
 }
 
 ObjectData* convCellToObjHelper(TypedValue tv) {