[MERGE #5707 @sigatrev] oopjit branch folding for BrEq,Neq with numbers, bools, null, undefined

Merge pull request #5707 from sigatrev:branchFolding

this commit handles branch folding checks for when operands are floats, booleans, null, or undefined. TryOptConstFoldBrEqual is already handling ints in a more robust way

lib/Backend/GlobOpt.cpp

@@ -6468,6 +6468,12 @@ GlobOpt::GetConstantVar(IR::Opnd *opnd, Value *val)
             return Js::TaggedInt::ToVarUnchecked(opnd->AsIntConstOpnd()->AsInt32());
         }
     }
+#if FLOATVAR
+    else if (opnd->IsFloatConstOpnd())
+    {
+        return Js::JavascriptNumber::ToVar(opnd->AsFloatConstOpnd()->m_value);
+    }
+#endif
     else if (opnd->IsRegOpnd() && opnd->AsRegOpnd()->m_sym->IsSingleDef())
     {
         if (valueInfo->IsBoolean())
@@ -6489,19 +6495,110 @@ GlobOpt::GetConstantVar(IR::Opnd *opnd, Value *val)
         {
             return (Js::Var)this->func->GetScriptContextInfo()->GetNullAddr();
         }
+#if FLOATVAR
+        else if (valueInfo->IsFloat())
+        {
+            IR::Instr * defInstr = opnd->AsRegOpnd()->m_sym->GetInstrDef();
+            if (defInstr->m_opcode == Js::OpCode::LdC_F8_R8 && defInstr->GetSrc1()->IsFloatConstOpnd())
+            {
+                return Js::JavascriptNumber::ToVar(defInstr->GetSrc1()->AsFloatConstOpnd()->m_value);
+            }
+        }
+#endif
     }
 
     return nullptr;
 }
 
-bool BoolAndIntStaticAndTypeMismatch(Value* src1Val, Value* src2Val, Js::Var src1Var, Js::Var src2Var)
+namespace
 {
-    ValueInfo *src1ValInfo = src1Val->GetValueInfo();
-    ValueInfo *src2ValInfo = src2Val->GetValueInfo();
-    return (src1ValInfo->IsNumber() && src1Var && src2ValInfo->IsBoolean() && src1Var != Js::TaggedInt::ToVarUnchecked(0) && src1Var != Js::TaggedInt::ToVarUnchecked(1)) ||
-        (src2ValInfo->IsNumber() && src2Var && src1ValInfo->IsBoolean() && src2Var != Js::TaggedInt::ToVarUnchecked(0) && src2Var != Js::TaggedInt::ToVarUnchecked(1));
-}
+    bool TryCompIntAndFloat(bool * result, Js::Var left, Js::Var right)
+    {
+        if (Js::TaggedInt::Is(left))
+        {
+            // If both are tagged ints we should not get here.
+            Assert(!Js::TaggedInt::Is(right));
+            if (Js::JavascriptNumber::Is_NoTaggedIntCheck(right))
+            {
+                double value = Js::JavascriptNumber::GetValue(right);
+                *result = (Js::TaggedInt::ToInt32(left) == value);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool Op_JitEq(bool * result, Value * src1Val, Value * src2Val, Js::Var src1Var, Js::Var src2Var, Func * func, bool isStrict)
+    {
+        Assert(src1Val != nullptr && src2Val != nullptr);
+        Assert(src1Var != nullptr && src2Var != nullptr);
+
+        if (src1Var == src2Var)
+        {
+            if (Js::TaggedInt::Is(src1Var))
+            {
+                *result = true;
+                return true;
+            }
+
+            if (!isStrict && src1Val->GetValueInfo()->IsNotFloat())
+            {
+                // If the vars are equal and they are not NaN, non-strict equal returns true. Not float guarantees not NaN.
+                *result = true;
+                return true;
+            }
+
+#if FLOATVAR
+            if (Js::JavascriptNumber::Is_NoTaggedIntCheck(src1Var))
+            {
+                *result = !Js::JavascriptNumber::IsNan(Js::JavascriptNumber::GetValue(src1Var));
+                return true;
+            }
+#endif
+
+            if (src1Var == reinterpret_cast<Js::Var>(func->GetScriptContextInfo()->GetTrueAddr()) ||
+                src1Var == reinterpret_cast<Js::Var>(func->GetScriptContextInfo()->GetFalseAddr()) ||
+                src1Var == reinterpret_cast<Js::Var>(func->GetScriptContextInfo()->GetNullAddr()) ||
+                src1Var == reinterpret_cast<Js::Var>(func->GetScriptContextInfo()->GetUndefinedAddr()))
+            {
+                *result = true;
+                return true;
+            }
+
+            // Other var comparisons require the runtime to prove.
+            return false;
+        }
+
+#if FLOATVAR
+        if (TryCompIntAndFloat(result, src1Var, src2Var) || TryCompIntAndFloat(result, src2Var, src1Var))
+        {
+            return true;
+        }
+
+#endif
 
+        return false;
+    }
+
+    bool Op_JitNeq(bool * result, Value * src1Val, Value * src2Val, Js::Var src1Var, Js::Var src2Var, Func * func, bool isStrict)
+    {
+        if (Op_JitEq(result, src1Val, src2Val, src1Var, src2Var, func, isStrict))
+        {
+            *result = !*result;
+            return true;
+        }
+
+        return false;
+    }
+
+    bool BoolAndIntStaticAndTypeMismatch(Value* src1Val, Value* src2Val, Js::Var src1Var, Js::Var src2Var)
+    {
+        ValueInfo *src1ValInfo = src1Val->GetValueInfo();
+        ValueInfo *src2ValInfo = src2Val->GetValueInfo();
+        return (src1ValInfo->IsNumber() && src1Var && src2ValInfo->IsBoolean() && src1Var != Js::TaggedInt::ToVarUnchecked(0) && src1Var != Js::TaggedInt::ToVarUnchecked(1)) ||
+            (src2ValInfo->IsNumber() && src2Var && src1ValInfo->IsBoolean() && src2Var != Js::TaggedInt::ToVarUnchecked(0) && src2Var != Js::TaggedInt::ToVarUnchecked(1));
+    }
+}
 
 bool
 GlobOpt::CanProveConditionalBranch(IR::Instr *instr, Value *src1Val, Value *src2Val, Js::Var src1Var, Js::Var src2Var, bool *result)
@@ -6629,12 +6726,10 @@ GlobOpt::CanProveConditionalBranch(IR::Instr *instr, Value *src1Val, Value *src2
         }
         else
         {
-            if (func->IsOOPJIT() || !CONFIG_FLAG(OOPJITMissingOpts))
+            if (!Op_JitEq(result, src1Val, src2Val, src1Var, src2Var, this->func, false /* isStrict */))
             {
-                // TODO: OOP JIT, const folding
                 return false;
             }
-            *result = Js::JavascriptOperators::Equal(src1Var, src2Var, this->func->GetScriptContext());
         }
         break;
     case Js::OpCode::BrNeq_A:
@@ -6661,12 +6756,10 @@ GlobOpt::CanProveConditionalBranch(IR::Instr *instr, Value *src1Val, Value *src2
         }
         else
         {
-            if (func->IsOOPJIT() || !CONFIG_FLAG(OOPJITMissingOpts))
+            if (!Op_JitNeq(result, src1Val, src2Val, src1Var, src2Var, this->func, false /* isStrict */))
             {
-                // TODO: OOP JIT, const folding
                 return false;
             }
-            *result = Js::JavascriptOperators::NotEqual(src1Var, src2Var, this->func->GetScriptContext());
         }
         break;
     case Js::OpCode::BrSrEq_A:
@@ -6702,12 +6795,10 @@ GlobOpt::CanProveConditionalBranch(IR::Instr *instr, Value *src1Val, Value *src2
         }
         else
         {
-            if (func->IsOOPJIT() || !CONFIG_FLAG(OOPJITMissingOpts))
+            if (!Op_JitEq(result, src1Val, src2Val, src1Var, src2Var, this->func, true /* isStrict */))
             {
-                // TODO: OOP JIT, const folding
                 return false;
             }
-            *result = Js::JavascriptOperators::StrictEqual(src1Var, src2Var, this->func->GetScriptContext());
         }
         break;
 
@@ -6744,12 +6835,10 @@ GlobOpt::CanProveConditionalBranch(IR::Instr *instr, Value *src1Val, Value *src2
         }
         else
         {
-            if (func->IsOOPJIT() || !CONFIG_FLAG(OOPJITMissingOpts))
+            if (!Op_JitNeq(result, src1Val, src2Val, src1Var, src2Var, this->func, true /* isStrict */))
             {
-                // TODO: OOP JIT, const folding
                 return false;
             }
-            *result = Js::JavascriptOperators::NotStrictEqual(src1Var, src2Var, this->func->GetScriptContext());
         }
         break;