Use maps instead of arrays for branch lookups

romainguy · May 16, 2024 · 38d40e0 · 38d40e0
1 parent 2c58dcc
commit 38d40e0
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Showing 2 changed files with 24 additions and 12 deletions.
diff --git a/src/jvmMain/kotlin/dev/romainguy/kotlin/explorer/code/CodeBuilder.kt b/src/jvmMain/kotlin/dev/romainguy/kotlin/explorer/code/CodeBuilder.kt
@@ -61,12 +61,11 @@ class CodeBuilder(private val codeStyle: CodeStyle) {
         var count = 0
         instructionSet.instructions.forEach { instruction ->
             val code = instruction.code
-            val index = code.indexOf(": ")
-            instructionSet.isa.branchInstructions.forEach out@ { opCode ->
-                if (code.startsWith(opCode, index + 2)) {
-                    count++
-                    return@out
-                }
+            val start = code.indexOf(": ") + 2
+            val end = code.indexOfFirst(start) { c -> !c.isLetter() }
+            val opCode = code.substring(start, end)
+            if (instructionSet.isa.branchInstructions.contains(opCode)) {
+                count++
             }
         }
         return count
@@ -115,4 +114,14 @@ class CodeBuilder(private val codeStyle: CodeStyle) {
         sb.append('\n')
         line++
     }
-}
+}
+
+private inline fun CharSequence.indexOfFirst(start: Int, predicate: (Char) -> Boolean): Int {
+    val end = length
+    for (index in start..<end ) {
+        if (predicate(this[index])) {
+            return index
+        }
+    }
+    return end
+}
diff --git a/src/jvmMain/kotlin/dev/romainguy/kotlin/explorer/code/DataModels.kt b/src/jvmMain/kotlin/dev/romainguy/kotlin/explorer/code/DataModels.kt
@@ -16,11 +16,14 @@
 
 package dev.romainguy.kotlin.explorer.code
 
-enum class ISA(val branchInstructions: Array<String>) {
-    ByteCode(arrayOf("if")),
-    Dex(arrayOf("if-")),
+import androidx.collection.ScatterSet
+import androidx.collection.scatterSetOf
+
+enum class ISA(val branchInstructions: ScatterSet<String>) {
+    ByteCode(scatterSetOf("if")),
+    Dex(scatterSetOf("if")),
     X86_64(
-        arrayOf(
+        scatterSetOf(
             "je",
             "jz",
             "jne",
@@ -45,7 +48,7 @@ enum class ISA(val branchInstructions: Array<String>) {
             "jna"
         )
     ),
-    Arm64(arrayOf("b.", "b ", "bl", "cbz", "cbnz", "tbz", "tbnz"))
+    Arm64(scatterSetOf("b", "bl", "cbz", "cbnz", "tbz", "tbnz"))
 }
 
 data class Class(val header: String, val methods: List<Method>)