Fix numeric fast-paths for Obj arithmetic

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/CmdRuntime.kt

@@ -871,14 +871,21 @@ class CmdAddObj(internal val a: Int, internal val b: Int, internal val dst: Int)
                 frame.setInt(dst, frame.frame.getInt(la) + frame.frame.getInt(lb))
                 return
             }
-            if (ta == SlotType.REAL.code || tb == SlotType.REAL.code) {
+            val aNumeric = ta == SlotType.INT.code || ta == SlotType.REAL.code
+            val bNumeric = tb == SlotType.INT.code || tb == SlotType.REAL.code
+            if (aNumeric && bNumeric && (ta == SlotType.REAL.code || tb == SlotType.REAL.code)) {
                 val av = if (ta == SlotType.REAL.code) frame.frame.getReal(la) else frame.frame.getInt(la).toDouble()
                 val bv = if (tb == SlotType.REAL.code) frame.frame.getReal(lb) else frame.frame.getInt(lb).toDouble()
                 frame.setReal(dst, av + bv)
                 return
             }
         }
-        frame.setObj(dst, frame.slotToObj(a).plus(frame.ensureScope(), frame.slotToObj(b)))
+        val result = frame.slotToObj(a).plus(frame.ensureScope(), frame.slotToObj(b))
+        when (result) {
+            is ObjInt -> frame.setInt(dst, result.value)
+            is ObjReal -> frame.setReal(dst, result.value)
+            else -> frame.setObj(dst, result)
+        }
         return
     }
 }
@@ -895,14 +902,21 @@ class CmdSubObj(internal val a: Int, internal val b: Int, internal val dst: Int)
                 frame.setInt(dst, frame.frame.getInt(la) - frame.frame.getInt(lb))
                 return
             }
-            if (ta == SlotType.REAL.code || tb == SlotType.REAL.code) {
+            val aNumeric = ta == SlotType.INT.code || ta == SlotType.REAL.code
+            val bNumeric = tb == SlotType.INT.code || tb == SlotType.REAL.code
+            if (aNumeric && bNumeric && (ta == SlotType.REAL.code || tb == SlotType.REAL.code)) {
                 val av = if (ta == SlotType.REAL.code) frame.frame.getReal(la) else frame.frame.getInt(la).toDouble()
                 val bv = if (tb == SlotType.REAL.code) frame.frame.getReal(lb) else frame.frame.getInt(lb).toDouble()
                 frame.setReal(dst, av - bv)
                 return
             }
         }
-        frame.setObj(dst, frame.slotToObj(a).minus(frame.ensureScope(), frame.slotToObj(b)))
+        val result = frame.slotToObj(a).minus(frame.ensureScope(), frame.slotToObj(b))
+        when (result) {
+            is ObjInt -> frame.setInt(dst, result.value)
+            is ObjReal -> frame.setReal(dst, result.value)
+            else -> frame.setObj(dst, result)
+        }
         return
     }
 }
@@ -919,14 +933,21 @@ class CmdMulObj(internal val a: Int, internal val b: Int, internal val dst: Int)
                 frame.setInt(dst, frame.frame.getInt(la) * frame.frame.getInt(lb))
                 return
             }
-            if (ta == SlotType.REAL.code || tb == SlotType.REAL.code) {
+            val aNumeric = ta == SlotType.INT.code || ta == SlotType.REAL.code
+            val bNumeric = tb == SlotType.INT.code || tb == SlotType.REAL.code
+            if (aNumeric && bNumeric && (ta == SlotType.REAL.code || tb == SlotType.REAL.code)) {
                 val av = if (ta == SlotType.REAL.code) frame.frame.getReal(la) else frame.frame.getInt(la).toDouble()
                 val bv = if (tb == SlotType.REAL.code) frame.frame.getReal(lb) else frame.frame.getInt(lb).toDouble()
                 frame.setReal(dst, av * bv)
                 return
             }
         }
-        frame.setObj(dst, frame.slotToObj(a).mul(frame.ensureScope(), frame.slotToObj(b)))
+        val result = frame.slotToObj(a).mul(frame.ensureScope(), frame.slotToObj(b))
+        when (result) {
+            is ObjInt -> frame.setInt(dst, result.value)
+            is ObjReal -> frame.setReal(dst, result.value)
+            else -> frame.setObj(dst, result)
+        }
         return
     }
 }
@@ -943,14 +964,21 @@ class CmdDivObj(internal val a: Int, internal val b: Int, internal val dst: Int)
                 frame.setInt(dst, frame.frame.getInt(la) / frame.frame.getInt(lb))
                 return
             }
-            if (ta == SlotType.REAL.code || tb == SlotType.REAL.code) {
+            val aNumeric = ta == SlotType.INT.code || ta == SlotType.REAL.code
+            val bNumeric = tb == SlotType.INT.code || tb == SlotType.REAL.code
+            if (aNumeric && bNumeric && (ta == SlotType.REAL.code || tb == SlotType.REAL.code)) {
                 val av = if (ta == SlotType.REAL.code) frame.frame.getReal(la) else frame.frame.getInt(la).toDouble()
                 val bv = if (tb == SlotType.REAL.code) frame.frame.getReal(lb) else frame.frame.getInt(lb).toDouble()
                 frame.setReal(dst, av / bv)
                 return
             }
         }
-        frame.setObj(dst, frame.slotToObj(a).div(frame.ensureScope(), frame.slotToObj(b)))
+        val result = frame.slotToObj(a).div(frame.ensureScope(), frame.slotToObj(b))
+        when (result) {
+            is ObjInt -> frame.setInt(dst, result.value)
+            is ObjReal -> frame.setReal(dst, result.value)
+            else -> frame.setObj(dst, result)
+        }
         return
     }
 }
@@ -967,14 +995,21 @@ class CmdModObj(internal val a: Int, internal val b: Int, internal val dst: Int)
                 frame.setInt(dst, frame.frame.getInt(la) % frame.frame.getInt(lb))
                 return
             }
-            if (ta == SlotType.REAL.code || tb == SlotType.REAL.code) {
+            val aNumeric = ta == SlotType.INT.code || ta == SlotType.REAL.code
+            val bNumeric = tb == SlotType.INT.code || tb == SlotType.REAL.code
+            if (aNumeric && bNumeric && (ta == SlotType.REAL.code || tb == SlotType.REAL.code)) {
                 val av = if (ta == SlotType.REAL.code) frame.frame.getReal(la) else frame.frame.getInt(la).toDouble()
                 val bv = if (tb == SlotType.REAL.code) frame.frame.getReal(lb) else frame.frame.getInt(lb).toDouble()
                 frame.setReal(dst, av % bv)
                 return
             }
         }
-        frame.setObj(dst, frame.slotToObj(a).mod(frame.ensureScope(), frame.slotToObj(b)))
+        val result = frame.slotToObj(a).mod(frame.ensureScope(), frame.slotToObj(b))
+        when (result) {
+            is ObjInt -> frame.setInt(dst, result.value)
+            is ObjReal -> frame.setReal(dst, result.value)
+            else -> frame.setObj(dst, result)
+        }
         return
     }
 }

lynglib/src/commonTest/kotlin/TypesTest.kt

@@ -96,4 +96,54 @@ class TypesTest {
             assertNotEquals(Point(0,1), p3)
         """.trimIndent())
     }
+
+    @Test
+    fun testNumericInference() = runTest {
+        eval("""
+            val x = 1
+            var y = 2.0
+            assert( x is Int )
+            assert( y is Real )
+            assert( x + y is Real )
+            assert( abs(x+y) is Real )
+            assert( abs(x/y) is Real )
+        """.trimIndent())
+    }
+    @Test
+    fun testNumericInferenceBug1() = runTest {
+        eval("""
+            fun findSumLimit(f) {
+                var sum = 0.0
+                for( n in 1..100 ) {
+                    val s0 = sum
+                    sum += f(n)
+                    assert( sum is Real )
+                    assert( s0 is Real )
+                    val delta = abs(sum - s0) / abs(sum)
+                    assert( delta is Real )
+                    println("abs(%g - %g) = %g"(sum, s0, abs(sum-s0)))
+                    if( s0 != 0 )
+                        assert( abs(sum-s0) < abs(sum) )
+                    println("abs(%g) = %g"(sum, abs(sum)))
+                    println( "delta calc: %g"(delta) )
+//                    if( n > 3 ) assert( delta < 1.0 )
+                    if( delta < 1.0e-4 ) {
+                        println("limit reached after "+n+" rounds")
+                        break sum
+                    }
+                    else
+                        println("%g, delta=%g"(sum, delta))
+                    n++
+                }
+                else {
+                    println("limit not reached")
+                    null
+                }
+            }
+            
+            val limit = findSumLimit { n -> 1.0/n/n }
+            assert( limit != null )
+            println("Result: "+limit)
+        """.trimIndent())
+    }
 }