Make the detailed reason for deopts mandatory on all platforms.

src/arm64/lithium-codegen-arm64.cc

Index: src/arm64/lithium-codegen-arm64.cc
diff --git a/src/arm64/lithium-codegen-arm64.cc b/src/arm64/lithium-codegen-arm64.cc
index 29986424629cf601c9a5045b04db266f74477da7..b9b67d9bbd01b1d5a5ce108e753d64d1f6fdd6eb 100644
--- a/src/arm64/lithium-codegen-arm64.cc
+++ b/src/arm64/lithium-codegen-arm64.cc
@@ -1063,9 +1063,8 @@ void LCodeGen::DeoptimizeBranch(
 }
 
 
-void LCodeGen::Deoptimize(LInstruction* instr,
-                          Deoptimizer::BailoutType* override_bailout_type,
-                          const char* detail) {
+void LCodeGen::Deoptimize(LInstruction* instr, const char* detail,
+                          Deoptimizer::BailoutType* override_bailout_type) {
   DeoptimizeBranch(instr, detail, always, NoReg, -1, override_bailout_type);
 }
 
@@ -1516,7 +1515,7 @@ void LCodeGen::DoAddI(LAddI* instr) {
 
   if (can_overflow) {
     __ Adds(result, left, right);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   } else {
     __ Add(result, left, right);
   }
@@ -1530,7 +1529,7 @@ void LCodeGen::DoAddS(LAddS* instr) {
   Operand right = ToOperand(instr->right());
   if (can_overflow) {
     __ Adds(result, left, right);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   } else {
     __ Add(result, left, right);
   }
@@ -1656,7 +1655,7 @@ void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
   // adaptor frame below it.
   const uint32_t kArgumentsLimit = 1 * KB;
   __ Cmp(length, kArgumentsLimit);
-  DeoptimizeIf(hi, instr);
+  DeoptimizeIf(hi, instr, "too many arguments");
 
   // Push the receiver and use the register to keep the original
   // number of arguments.
@@ -1838,7 +1837,7 @@ void LCodeGen::DoBoundsCheck(LBoundsCheck *instr) {
   if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
     __ Assert(NegateCondition(cond), kEliminatedBoundsCheckFailed);
   } else {
-    DeoptimizeIf(cond, instr);
+    DeoptimizeIf(cond, instr, "out of bounds");
   }
 }
 
@@ -1917,7 +1916,7 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ JumpIfSmi(value, true_label);
       } else if (expected.NeedsMap()) {
         // If we need a map later and have a smi, deopt.
-        DeoptimizeIfSmi(value, instr);
+        DeoptimizeIfSmi(value, instr, "Smi");
       }
 
       Register map = NoReg;
@@ -1978,7 +1977,7 @@ void LCodeGen::DoBranch(LBranch* instr) {
       if (!expected.IsGeneric()) {
         // We've seen something for the first time -> deopt.
         // This can only happen if we are not generic already.
-        Deoptimize(instr);
+        Deoptimize(instr, "unexpected object");
       }
     }
   }
@@ -2163,7 +2162,7 @@ void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
         instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
     __ StoreToSafepointRegisterSlot(x0, temp);
   }
-  DeoptimizeIfSmi(temp, instr);
+  DeoptimizeIfSmi(temp, instr, "instance migration failed");
 }
 
 
@@ -2218,7 +2217,7 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
   if (instr->hydrogen()->HasMigrationTarget()) {
     __ B(ne, deferred->entry());
   } else {
-    DeoptimizeIf(ne, instr);
+    DeoptimizeIf(ne, instr, "wrong map");
   }
 
   __ Bind(&success);
@@ -2227,7 +2226,7 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
 
 void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
   if (!instr->hydrogen()->value()->type().IsHeapObject()) {
-    DeoptimizeIfSmi(ToRegister(instr->value()), instr);
+    DeoptimizeIfSmi(ToRegister(instr->value()), instr, "Smi");
   }
 }
 
@@ -2235,7 +2234,7 @@ void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
 void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
   Register value = ToRegister(instr->value());
   DCHECK(!instr->result() || ToRegister(instr->result()).Is(value));
-  DeoptimizeIfNotSmi(value, instr);
+  DeoptimizeIfNotSmi(value, instr, "not a Smi");
 }
 
 
@@ -2253,15 +2252,15 @@ void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
     __ Cmp(scratch, first);
     if (first == last) {
       // If there is only one type in the interval check for equality.
-      DeoptimizeIf(ne, instr);
+      DeoptimizeIf(ne, instr, "wrong instance type");
     } else if (last == LAST_TYPE) {
       // We don't need to compare with the higher bound of the interval.
-      DeoptimizeIf(lo, instr);
+      DeoptimizeIf(lo, instr, "wrong instance type");
     } else {
       // If we are below the lower bound, set the C flag and clear the Z flag
       // to force a deopt.
       __ Ccmp(scratch, last, CFlag, hs);
-      DeoptimizeIf(hi, instr);
+      DeoptimizeIf(hi, instr, "wrong instance type");
     }
   } else {
     uint8_t mask;
@@ -2271,9 +2270,11 @@ void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
     if (base::bits::IsPowerOfTwo32(mask)) {
       DCHECK((tag == 0) || (tag == mask));
       if (tag == 0) {
-        DeoptimizeIfBitSet(scratch, MaskToBit(mask), instr);
+        DeoptimizeIfBitSet(scratch, MaskToBit(mask), instr,
+                           "wrong instance type");
       } else {
-        DeoptimizeIfBitClear(scratch, MaskToBit(mask), instr);
+        DeoptimizeIfBitClear(scratch, MaskToBit(mask), instr,
+                             "wrong instance type");
       }
     } else {
       if (tag == 0) {
@@ -2282,7 +2283,7 @@ void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
         __ And(scratch, scratch, mask);
         __ Cmp(scratch, tag);
       }
-      DeoptimizeIf(ne, instr);
+      DeoptimizeIf(ne, instr, "wrong instance type");
     }
   }
 }
@@ -2321,7 +2322,8 @@ void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
   __ JumpIfHeapNumber(input, &is_heap_number);
 
   // Check for undefined. Undefined is coverted to zero for clamping conversion.
-  DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
+  DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr,
+                      "not a heap number/undefined");
   __ Mov(result, 0);
   __ B(&done);
 
@@ -2626,7 +2628,7 @@ void LCodeGen::DoCheckValue(LCheckValue* instr) {
   } else {
     __ Cmp(reg, Operand(object));
   }
-  DeoptimizeIf(ne, instr);
+  DeoptimizeIf(ne, instr, "value mismatch");
 }
 
 
@@ -2650,9 +2652,9 @@ void LCodeGen::DoDateField(LDateField* instr) {
   DCHECK(object.is(result) && object.Is(x0));
   DCHECK(instr->IsMarkedAsCall());
 
-  DeoptimizeIfSmi(object, instr);
+  DeoptimizeIfSmi(object, instr, "Smi");
   __ CompareObjectType(object, temp1, temp1, JS_DATE_TYPE);
-  DeoptimizeIf(ne, instr);
+  DeoptimizeIf(ne, instr, "not a date object");
 
   if (index->value() == 0) {
     __ Ldr(result, FieldMemOperand(object, JSDate::kValueOffset));
@@ -2688,7 +2690,7 @@ void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
     type = Deoptimizer::LAZY;
   }
 
-  Deoptimize(instr, &type, instr->hydrogen()->reason());
+  Deoptimize(instr, instr->hydrogen()->reason(), &type);
 }
 
 
@@ -2702,21 +2704,21 @@ void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
   // Check for (0 / -x) that will produce negative zero.
   HDiv* hdiv = instr->hydrogen();
   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
-    DeoptimizeIfZero(dividend, instr);
+    DeoptimizeIfZero(dividend, instr, "division by zero");
   }
   // Check for (kMinInt / -1).
   if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
     // Test dividend for kMinInt by subtracting one (cmp) and checking for
     // overflow.
     __ Cmp(dividend, 1);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   }
   // Deoptimize if remainder will not be 0.
   if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
       divisor != 1 && divisor != -1) {
     int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
     __ Tst(dividend, mask);
-    DeoptimizeIf(ne, instr);
+    DeoptimizeIf(ne, instr, "lost precision");
   }
 
   if (divisor == -1) {  // Nice shortcut, not needed for correctness.
@@ -2744,14 +2746,14 @@ void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
   DCHECK(!AreAliased(dividend, result));
 
   if (divisor == 0) {
-    Deoptimize(instr);
+    Deoptimize(instr, "division by zero");
     return;
   }
 
   // Check for (0 / -x) that will produce negative zero.
   HDiv* hdiv = instr->hydrogen();
   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
-    DeoptimizeIfZero(dividend, instr);
+    DeoptimizeIfZero(dividend, instr, "minus zero");
   }
 
   __ TruncatingDiv(result, dividend, Abs(divisor));
@@ -2763,7 +2765,7 @@ void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
     __ Sxtw(dividend.X(), dividend);
     __ Mov(temp, divisor);
     __ Smsubl(temp.X(), result, temp, dividend.X());
-    DeoptimizeIfNotZero(temp, instr);
+    DeoptimizeIfNotZero(temp, instr, "lost precision");
   }
 }
 
@@ -2786,7 +2788,7 @@ void LCodeGen::DoDivI(LDivI* instr) {
 
   // Check for x / 0.
   if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
-    DeoptimizeIfZero(divisor, instr);
+    DeoptimizeIfZero(divisor, instr, "division by zero");
   }
 
   // Check for (0 / -x) as that will produce negative zero.
@@ -2798,7 +2800,7 @@ void LCodeGen::DoDivI(LDivI* instr) {
     // If the divisor >= 0 (pl, the opposite of mi) set the flags to
     // condition ne, so we don't deopt, ie. positive divisor doesn't deopt.
     __ Ccmp(dividend, 0, NoFlag, mi);
-    DeoptimizeIf(eq, instr);
+    DeoptimizeIf(eq, instr, "minus zero");
   }
 
   // Check for (kMinInt / -1).
@@ -2810,13 +2812,13 @@ void LCodeGen::DoDivI(LDivI* instr) {
     // -1. If overflow is clear, set the flags for condition ne, as the
     // dividend isn't -1, and thus we shouldn't deopt.
     __ Ccmp(divisor, -1, NoFlag, vs);
-    DeoptimizeIf(eq, instr);
+    DeoptimizeIf(eq, instr, "overflow");
   }
 
   // Compute remainder and deopt if it's not zero.
   Register remainder = ToRegister32(instr->temp());
   __ Msub(remainder, result, divisor, dividend);
-  DeoptimizeIfNotZero(remainder, instr);
+  DeoptimizeIfNotZero(remainder, instr, "lost precision");
 }
 
 
@@ -2825,11 +2827,11 @@ void LCodeGen::DoDoubleToIntOrSmi(LDoubleToIntOrSmi* instr) {
   Register result = ToRegister32(instr->result());
 
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-    DeoptimizeIfMinusZero(input, instr);
+    DeoptimizeIfMinusZero(input, instr, "minus zero");
   }
 
   __ TryRepresentDoubleAsInt32(result, input, double_scratch());
-  DeoptimizeIf(ne, instr);
+  DeoptimizeIf(ne, instr, "lost precision or NaN");
 
   if (instr->tag_result()) {
     __ SmiTag(result.X());
@@ -2890,7 +2892,7 @@ void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
   __ LoadInstanceDescriptors(map, result);
   __ Ldr(result, FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
   __ Ldr(result, FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
-  DeoptimizeIfZero(result, instr);
+  DeoptimizeIfZero(result, instr, "no cache");
 
   __ Bind(&done);
 }
@@ -2903,17 +2905,17 @@ void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
   DCHECK(instr->IsMarkedAsCall());
   DCHECK(object.Is(x0));
 
-  DeoptimizeIfRoot(object, Heap::kUndefinedValueRootIndex, instr);
+  DeoptimizeIfRoot(object, Heap::kUndefinedValueRootIndex, instr, "undefined");
 
   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   __ Cmp(object, null_value);
-  DeoptimizeIf(eq, instr);
+  DeoptimizeIf(eq, instr, "null");
 
-  DeoptimizeIfSmi(object, instr);
+  DeoptimizeIfSmi(object, instr, "Smi");
 
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ CompareObjectType(object, x1, x1, LAST_JS_PROXY_TYPE);
-  DeoptimizeIf(le, instr);
+  DeoptimizeIf(le, instr, "not a JavaScript object");
 
   Label use_cache, call_runtime;
   __ CheckEnumCache(object, null_value, x1, x2, x3, x4, &call_runtime);
@@ -2927,7 +2929,7 @@ void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
   CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);
 
   __ Ldr(x1, FieldMemOperand(object, HeapObject::kMapOffset));
-  DeoptimizeIfNotRoot(x1, Heap::kMetaMapRootIndex, instr);
+  DeoptimizeIfNotRoot(x1, Heap::kMetaMapRootIndex, instr, "wrong map");
 
   __ Bind(&use_cache);
 }
@@ -3320,7 +3322,7 @@ void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   __ Ldr(result, ContextMemOperand(context, instr->slot_index()));
   if (instr->hydrogen()->RequiresHoleCheck()) {
     if (instr->hydrogen()->DeoptimizesOnHole()) {
-      DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
+      DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr, "hole");
     } else {
       Label not_the_hole;
       __ JumpIfNotRoot(result, Heap::kTheHoleValueRootIndex, &not_the_hole);
@@ -3341,7 +3343,7 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
                                  JSFunction::kPrototypeOrInitialMapOffset));
 
   // Check that the function has a prototype or an initial map.
-  DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
+  DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr, "hole");
 
   // If the function does not have an initial map, we're done.
   Label done;
@@ -3361,7 +3363,7 @@ void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   __ Mov(result, Operand(Handle<Object>(instr->hydrogen()->cell().handle())));
   __ Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
+    DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr, "hole");
   }
 }
 
@@ -3492,7 +3494,7 @@ void LCodeGen::DoLoadKeyedExternal(LLoadKeyedExternal* instr) {
         if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
           // Deopt if value > 0x80000000.
           __ Tst(result, 0xFFFFFFFF80000000);
-          DeoptimizeIf(ne, instr);
+          DeoptimizeIf(ne, instr, "negative value");
         }
         break;
       case FLOAT32_ELEMENTS:
@@ -3589,7 +3591,7 @@ void LCodeGen::DoLoadKeyedFixedDouble(LLoadKeyedFixedDouble* instr) {
     STATIC_ASSERT(kHoleNanInt64 == 0x7fffffffffffffff);
     __ Ldr(scratch, mem_op);
     __ Cmn(scratch, 1);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "hole");
   }
 }
 
@@ -3627,9 +3629,9 @@ void LCodeGen::DoLoadKeyedFixed(LLoadKeyedFixed* instr) {
 
   if (instr->hydrogen()->RequiresHoleCheck()) {
     if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
-      DeoptimizeIfNotSmi(result, instr);
+      DeoptimizeIfNotSmi(result, instr, "not a Smi");
     } else {
-      DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
+      DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr, "hole");
     }
   }
 }
@@ -3731,7 +3733,7 @@ void LCodeGen::DoMathAbs(LMathAbs* instr) {
     Register result = r.IsSmi() ? ToRegister(instr->result())
                                 : ToRegister32(instr->result());
     __ Abs(result, input);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   }
 }
 
@@ -3883,7 +3885,7 @@ void LCodeGen::DoMathFloorI(LMathFloorI* instr) {
   Register result = ToRegister(instr->result());
 
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-    DeoptimizeIfMinusZero(input, instr);
+    DeoptimizeIfMinusZero(input, instr, "minus zero");
   }
 
   __ Fcvtms(result, input);
@@ -3893,7 +3895,7 @@ void LCodeGen::DoMathFloorI(LMathFloorI* instr) {
   __ Cmp(result, Operand(result, SXTW));
   //  - The input was not NaN.
   __ Fccmp(input, input, NoFlag, eq);
-  DeoptimizeIf(ne, instr);
+  DeoptimizeIf(ne, instr, "lost precision or NaN");
 }
 
 
@@ -3919,13 +3921,13 @@ void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
   // If the divisor is negative, we have to negate and handle edge cases.
   __ Negs(result, dividend);
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-    DeoptimizeIf(eq, instr);
+    DeoptimizeIf(eq, instr, "minus zero");
   }
 
   // Dividing by -1 is basically negation, unless we overflow.
   if (divisor == -1) {
     if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
-      DeoptimizeIf(vs, instr);
+      DeoptimizeIf(vs, instr, "overflow");
     }
     return;
   }
@@ -3948,14 +3950,14 @@ void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
   DCHECK(!AreAliased(dividend, result));
 
   if (divisor == 0) {
-    Deoptimize(instr);
+    Deoptimize(instr, "division by zero");
     return;
   }
 
   // Check for (0 / -x) that will produce negative zero.
   HMathFloorOfDiv* hdiv = instr->hydrogen();
   if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
-    DeoptimizeIfZero(dividend, instr);
+    DeoptimizeIfZero(dividend, instr, "minus zero");
   }
 
   // Easy case: We need no dynamic check for the dividend and the flooring
@@ -3998,14 +4000,14 @@ void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
   __ Sdiv(result, dividend, divisor);
 
   // Check for x / 0.
-  DeoptimizeIfZero(divisor, instr);
+  DeoptimizeIfZero(divisor, instr, "division by zero");
 
   // Check for (kMinInt / -1).
   if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
     // The V flag will be set iff dividend == kMinInt.
     __ Cmp(dividend, 1);
     __ Ccmp(divisor, -1, NoFlag, vs);
-    DeoptimizeIf(eq, instr);
+    DeoptimizeIf(eq, instr, "overflow");
   }
 
   // Check for (0 / -x) that will produce negative zero.
@@ -4015,7 +4017,7 @@ void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
     // "divisor" can't be null because the code would have already been
     // deoptimized. The Z flag is set only if (divisor < 0) and (dividend == 0).
     // In this case we need to deoptimize to produce a -0.
-    DeoptimizeIf(eq, instr);
+    DeoptimizeIf(eq, instr, "minus zero");
   }
 
   Label done;
@@ -4174,18 +4176,18 @@ void LCodeGen::DoMathRoundI(LMathRoundI* instr) {
 
   // Deoptimize if the result > 1, as it must be larger than 32 bits.
   __ Cmp(result, 1);
-  DeoptimizeIf(hi, instr);
+  DeoptimizeIf(hi, instr, "overflow");
 
   // Deoptimize for negative inputs, which at this point are only numbers in
   // the range [-0.5, -0.0]
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     __ Fmov(result, input);
-    DeoptimizeIfNegative(result, instr);
+    DeoptimizeIfNegative(result, instr, "minus zero");
   }
 
   // Deoptimize if the input was NaN.
   __ Fcmp(input, dot_five);
-  DeoptimizeIf(vs, instr);
+  DeoptimizeIf(vs, instr, "NaN");
 
   // Now, the only unhandled inputs are in the range [0.0, 1.5[ (or [-0.5, 1.5[
   // if we didn't generate a -0.0 bailout). If input >= 0.5 then return 1,
@@ -4263,7 +4265,7 @@ void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
     __ And(dividend, dividend, mask);
     __ Negs(dividend, dividend);
     if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
-      DeoptimizeIf(eq, instr);
+      DeoptimizeIf(eq, instr, "minus zero");
     }
     __ B(&done);
   }
@@ -4282,7 +4284,7 @@ void LCodeGen::DoModByConstI(LModByConstI* instr) {
   DCHECK(!AreAliased(dividend, result, temp));
 
   if (divisor == 0) {
-    Deoptimize(instr);
+    Deoptimize(instr, "division by zero");
     return;
   }
 
@@ -4296,7 +4298,7 @@ void LCodeGen::DoModByConstI(LModByConstI* instr) {
   if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
     Label remainder_not_zero;
     __ Cbnz(result, &remainder_not_zero);
-    DeoptimizeIfNegative(dividend, instr);
+    DeoptimizeIfNegative(dividend, instr, "minus zero");
     __ bind(&remainder_not_zero);
   }
 }
@@ -4311,12 +4313,12 @@ void LCodeGen::DoModI(LModI* instr) {
   // modulo = dividend - quotient * divisor
   __ Sdiv(result, dividend, divisor);
   if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
-    DeoptimizeIfZero(divisor, instr);
+    DeoptimizeIfZero(divisor, instr, "division by zero");
   }
   __ Msub(result, result, divisor, dividend);
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     __ Cbnz(result, &done);
-    DeoptimizeIfNegative(dividend, instr);
+    DeoptimizeIfNegative(dividend, instr, "minus zero");
   }
   __ Bind(&done);
 }
@@ -4339,10 +4341,10 @@ void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
   if (bailout_on_minus_zero) {
     if (right < 0) {
       // The result is -0 if right is negative and left is zero.
-      DeoptimizeIfZero(left, instr);
+      DeoptimizeIfZero(left, instr, "minus zero");
     } else if (right == 0) {
       // The result is -0 if the right is zero and the left is negative.
-      DeoptimizeIfNegative(left, instr);
+      DeoptimizeIfNegative(left, instr, "minus zero");
     }
   }
 
@@ -4352,7 +4354,7 @@ void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
       if (can_overflow) {
         // Only 0x80000000 can overflow here.
         __ Negs(result, left);
-        DeoptimizeIf(vs, instr);
+        DeoptimizeIf(vs, instr, "overflow");
       } else {
         __ Neg(result, left);
       }
@@ -4368,7 +4370,7 @@ void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
     case 2:
       if (can_overflow) {
         __ Adds(result, left, left);
-        DeoptimizeIf(vs, instr);
+        DeoptimizeIf(vs, instr, "overflow");
       } else {
         __ Add(result, left, left);
       }
@@ -4387,7 +4389,7 @@ void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
           DCHECK(!AreAliased(scratch, left));
           __ Cls(scratch, left);
           __ Cmp(scratch, right_log2);
-          DeoptimizeIf(lt, instr);
+          DeoptimizeIf(lt, instr, "overflow");
         }
 
         if (right >= 0) {
@@ -4397,7 +4399,7 @@ void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
           // result = -left << log2(-right)
           if (can_overflow) {
             __ Negs(result, Operand(left, LSL, right_log2));
-            DeoptimizeIf(vs, instr);
+            DeoptimizeIf(vs, instr, "overflow");
           } else {
             __ Neg(result, Operand(left, LSL, right_log2));
           }
@@ -4455,13 +4457,13 @@ void LCodeGen::DoMulI(LMulI* instr) {
     //  - If so (eq), set N (mi) if left + right is negative.
     //  - Otherwise, clear N.
     __ Ccmn(left, right, NoFlag, eq);
-    DeoptimizeIf(mi, instr);
+    DeoptimizeIf(mi, instr, "minus zero");
   }
 
   if (can_overflow) {
     __ Smull(result.X(), left, right);
     __ Cmp(result.X(), Operand(result, SXTW));
-    DeoptimizeIf(ne, instr);
+    DeoptimizeIf(ne, instr, "overflow");
   } else {
     __ Mul(result, left, right);
   }
@@ -4485,7 +4487,7 @@ void LCodeGen::DoMulS(LMulS* instr) {
     //  - If so (eq), set N (mi) if left + right is negative.
     //  - Otherwise, clear N.
     __ Ccmn(left, right, NoFlag, eq);
-    DeoptimizeIf(mi, instr);
+    DeoptimizeIf(mi, instr, "minus zero");
   }
 
   STATIC_ASSERT((kSmiShift == 32) && (kSmiTag == 0));
@@ -4493,7 +4495,7 @@ void LCodeGen::DoMulS(LMulS* instr) {
     __ Smulh(result, left, right);
     __ Cmp(result, Operand(result.W(), SXTW));
     __ SmiTag(result);
-    DeoptimizeIf(ne, instr);
+    DeoptimizeIf(ne, instr, "overflow");
   } else {
     if (AreAliased(result, left, right)) {
       // All three registers are the same: half untag the input and then
@@ -4669,13 +4671,14 @@ void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
     // Load heap number.
     __ Ldr(result, FieldMemOperand(input, HeapNumber::kValueOffset));
     if (instr->hydrogen()->deoptimize_on_minus_zero()) {
-      DeoptimizeIfMinusZero(result, instr);
+      DeoptimizeIfMinusZero(result, instr, "minus zero");
     }
     __ B(&done);
 
     if (can_convert_undefined_to_nan) {
       __ Bind(&convert_undefined);
-      DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
+      DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr,
+                          "not a heap number/undefined");
 
       __ LoadRoot(scratch, Heap::kNanValueRootIndex);
       __ Ldr(result, FieldMemOperand(scratch, HeapNumber::kValueOffset));
@@ -4868,7 +4871,7 @@ void LCodeGen::DoSmiTag(LSmiTag* instr) {
   Register output = ToRegister(instr->result());
   if (hchange->CheckFlag(HValue::kCanOverflow) &&
       hchange->value()->CheckFlag(HValue::kUint32)) {
-    DeoptimizeIfNegative(input.W(), instr);
+    DeoptimizeIfNegative(input.W(), instr, "overflow");
   }
   __ SmiTag(output, input);
 }
@@ -4880,7 +4883,7 @@ void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
   Label done, untag;
 
   if (instr->needs_check()) {
-    DeoptimizeIfNotSmi(input, instr);
+    DeoptimizeIfNotSmi(input, instr, "not a Smi");
   }
 
   __ Bind(&untag);
@@ -4905,7 +4908,7 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
         if (instr->can_deopt()) {
           // If `left >>> right` >= 0x80000000, the result is not representable
           // in a signed 32-bit smi.
-          DeoptimizeIfNegative(result, instr);
+          DeoptimizeIfNegative(result, instr, "negative value");
         }
         break;
       default: UNREACHABLE();
@@ -4915,7 +4918,7 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
     int shift_count = JSShiftAmountFromLConstant(right_op);
     if (shift_count == 0) {
       if ((instr->op() == Token::SHR) && instr->can_deopt()) {
-        DeoptimizeIfNegative(left, instr);
+        DeoptimizeIfNegative(left, instr, "negative value");
       }
       __ Mov(result, left, kDiscardForSameWReg);
     } else {
@@ -4968,7 +4971,7 @@ void LCodeGen::DoShiftS(LShiftS* instr) {
         if (instr->can_deopt()) {
           // If `left >>> right` >= 0x80000000, the result is not representable
           // in a signed 32-bit smi.
-          DeoptimizeIfNegative(result, instr);
+          DeoptimizeIfNegative(result, instr, "negative value");
         }
         break;
       default: UNREACHABLE();
@@ -4978,7 +4981,7 @@ void LCodeGen::DoShiftS(LShiftS* instr) {
     int shift_count = JSShiftAmountFromLConstant(right_op);
     if (shift_count == 0) {
       if ((instr->op() == Token::SHR) && instr->can_deopt()) {
-        DeoptimizeIfNegative(left, instr);
+        DeoptimizeIfNegative(left, instr, "negative value");
       }
       __ Mov(result, left);
     } else {
@@ -5107,7 +5110,7 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   if (instr->hydrogen()->RequiresHoleCheck()) {
     __ Ldr(scratch, target);
     if (instr->hydrogen()->DeoptimizesOnHole()) {
-      DeoptimizeIfRoot(scratch, Heap::kTheHoleValueRootIndex, instr);
+      DeoptimizeIfRoot(scratch, Heap::kTheHoleValueRootIndex, instr, "hole");
     } else {
       __ JumpIfNotRoot(scratch, Heap::kTheHoleValueRootIndex, &skip_assignment);
     }
@@ -5145,7 +5148,7 @@ void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
   if (instr->hydrogen()->RequiresHoleCheck()) {
     Register payload = ToRegister(instr->temp2());
     __ Ldr(payload, FieldMemOperand(cell, Cell::kValueOffset));
-    DeoptimizeIfRoot(payload, Heap::kTheHoleValueRootIndex, instr);
+    DeoptimizeIfRoot(payload, Heap::kTheHoleValueRootIndex, instr, "hole");
   }
 
   // Store the value.
@@ -5562,7 +5565,7 @@ void LCodeGen::DoSubI(LSubI* instr) {
 
   if (can_overflow) {
     __ Subs(result, left, right);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   } else {
     __ Sub(result, left, right);
   }
@@ -5576,7 +5579,7 @@ void LCodeGen::DoSubS(LSubS* instr) {
   Operand right = ToOperand(instr->right());
   if (can_overflow) {
     __ Subs(result, left, right);
-    DeoptimizeIf(vs, instr);
+    DeoptimizeIf(vs, instr, "overflow");
   } else {
     __ Sub(result, left, right);
   }
@@ -5616,7 +5619,8 @@ void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr,
 
     // Output contains zero, undefined is converted to zero for truncating
     // conversions.
-    DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
+    DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr,
+                        "not a heap number/undefined/true/false");
   } else {
     Register output = ToRegister32(instr->result());
     DoubleRegister dbl_scratch2 = ToDoubleRegister(temp2);
@@ -5774,7 +5778,7 @@ void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
 
   Label no_memento_found;
   __ TestJSArrayForAllocationMemento(object, temp1, temp2, &no_memento_found);
-  DeoptimizeIf(eq, instr);
+  DeoptimizeIf(eq, instr, "memento found");
   __ Bind(&no_memento_found);
 }
 
@@ -5899,7 +5903,7 @@ void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
   Register temp = ToRegister(instr->temp());
   __ Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
   __ Cmp(map, temp);
-  DeoptimizeIf(ne, instr);
+  DeoptimizeIf(ne, instr, "wrong map");
 }
 
 
@@ -5933,10 +5937,10 @@ void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
   __ JumpIfRoot(receiver, Heap::kUndefinedValueRootIndex, &global_object);
 
   // Deoptimize if the receiver is not a JS object.
-  DeoptimizeIfSmi(receiver, instr);
+  DeoptimizeIfSmi(receiver, instr, "Smi");
   __ CompareObjectType(receiver, result, result, FIRST_SPEC_OBJECT_TYPE);
   __ B(ge, &copy_receiver);
-  Deoptimize(instr);
+  Deoptimize(instr, "not a JavaScript object");
 
   __ Bind(&global_object);
   __ Ldr(result, FieldMemOperand(function, JSFunction::kContextOffset));