From 41094e63da244314b07bb7043d519600b018d9dc Mon Sep 17 00:00:00 2001
From: Iaroslav <postovalovya@gmail.com>
Date: Sat, 6 Jun 2020 21:48:52 +0700
Subject: [PATCH] Optimize number constants placing to economize contant pool
 places

---
 .../kmath/expressions/MethodVisitors.kt       | 42 +++++++++++++------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/kmath-asm/src/main/kotlin/scientifik/kmath/expressions/MethodVisitors.kt b/kmath-asm/src/main/kotlin/scientifik/kmath/expressions/MethodVisitors.kt
index 5b9a8afe8..dc5d83ea5 100644
--- a/kmath-asm/src/main/kotlin/scientifik/kmath/expressions/MethodVisitors.kt
+++ b/kmath-asm/src/main/kotlin/scientifik/kmath/expressions/MethodVisitors.kt
@@ -3,17 +3,28 @@ package scientifik.kmath.expressions
 import org.objectweb.asm.MethodVisitor
 import org.objectweb.asm.Opcodes.*
 
-fun MethodVisitor.visitLdcOrIConstInsn(value: Int) {
-    when (value) {
-        -1 -> visitInsn(ICONST_M1)
-        0 -> visitInsn(ICONST_0)
-        1 -> visitInsn(ICONST_1)
-        2 -> visitInsn(ICONST_2)
-        3 -> visitInsn(ICONST_3)
-        4 -> visitInsn(ICONST_4)
-        5 -> visitInsn(ICONST_5)
-        else -> visitLdcInsn(value)
-    }
+fun MethodVisitor.visitLdcOrIConstInsn(value: Int) = when (value) {
+    -1 -> visitInsn(ICONST_M1)
+    0 -> visitInsn(ICONST_0)
+    1 -> visitInsn(ICONST_1)
+    2 -> visitInsn(ICONST_2)
+    3 -> visitInsn(ICONST_3)
+    4 -> visitInsn(ICONST_4)
+    5 -> visitInsn(ICONST_5)
+    else -> visitLdcInsn(value)
+}
+
+fun MethodVisitor.visitLdcOrDConstInsn(value: Double) = when (value) {
+    0.0 -> visitInsn(DCONST_0)
+    1.0 -> visitInsn(DCONST_1)
+    else -> visitLdcInsn(value)
+}
+
+fun MethodVisitor.visitLdcOrFConstInsn(value: Float) = when (value) {
+    0f -> visitInsn(FCONST_0)
+    1f -> visitInsn(FCONST_1)
+    2f -> visitInsn(FCONST_2)
+    else -> visitLdcInsn(value)
 }
 
 private val signatureLetters = mapOf(
@@ -29,6 +40,13 @@ private val signatureLetters = mapOf(
 fun MethodVisitor.visitBoxedNumberConstant(number: Number) {
     val clazz = number.javaClass
     val c = clazz.name.replace('.', '/')
-    visitLdcInsn(number)
+
+    when (number) {
+        is Int -> visitLdcOrIConstInsn(number)
+        is Double -> visitLdcOrDConstInsn(number)
+        is Float -> visitLdcOrFConstInsn(number)
+        else -> visitLdcInsn(number)
+    }
+
     visitMethodInsn(INVOKESTATIC, c, "valueOf", "(${signatureLetters[clazz]})L${c};", false)
 }