From 7c69d38588c00b39e7f5e04641226bed83c899a6 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Mon, 7 Oct 2024 20:39:49 +0200
Subject: [PATCH] scan all asmsubs to see if another subroutine is referenced.
 Fixes #153

---
 compiler/test/TestOptimization.kt           | 24 +++++++++++++++++++++
 compilerAst/src/prog8/compiler/CallGraph.kt | 18 +++++++++-------
 examples/test.p8                            | 23 ++++++++++++++------
 3 files changed, 51 insertions(+), 14 deletions(-)

diff --git a/compiler/test/TestOptimization.kt b/compiler/test/TestOptimization.kt
index fb91af9d0..a9080013e 100644
--- a/compiler/test/TestOptimization.kt
+++ b/compiler/test/TestOptimization.kt
@@ -47,6 +47,30 @@ class TestOptimization: FunSpec({
         }
     }
 
+    test("scan all asmsubs to see if another subroutine is referenced") {
+        val src="""
+main {
+    sub foo() {
+        cx16.r0++
+    }
+    asmsub baz() {
+        %asm{{
+            jsr p8s_foo
+        }}
+    }
+    asmsub bar() {
+        %asm{{
+            inx
+            jmp p8s_foo
+        }}
+    }
+    sub start() {
+        bar()
+    }
+}"""
+        compileText(C64Target(), true, src) shouldNotBe null
+    }
+
     test("don't remove empty subroutine if it's referenced") {
         val sourcecode = """
             main {
diff --git a/compilerAst/src/prog8/compiler/CallGraph.kt b/compilerAst/src/prog8/compiler/CallGraph.kt
index 8b5ec582d..9abb45f24 100644
--- a/compilerAst/src/prog8/compiler/CallGraph.kt
+++ b/compilerAst/src/prog8/compiler/CallGraph.kt
@@ -162,20 +162,22 @@ class CallGraph(private val program: Program) : IAstVisitor {
     fun unused(sub: Subroutine): Boolean {
         if(sub in usedSubroutines)
             return false
-        val asm = nameInAssemblyCode(sub.name, listOf("p8s_", ""))
-        if(asm!=null) {
+        val asms = nameInAssemblyCode(sub.name, listOf("p8s_", ""))
+        if(asms.isEmpty())
+            return true
+        val allUnused = asms.all { asm->
             // check that the asm block that calls us, is inside a subroutine that is unused or not
             val containingSub = asm.definingSubroutine
-            return if(containingSub != null && containingSub !== sub)
+            if(containingSub != null && containingSub !== sub)
                 unused(containingSub)
             else
                 false
         }
-        return true
+        return allUnused
     }
 
     fun unused(block: Block): Boolean {
-        return block !in usedBlocks && nameInAssemblyCode(block.name, listOf("p8b_", ""))==null
+        return block !in usedBlocks && nameInAssemblyCode(block.name, listOf("p8b_", "")).isEmpty()
     }
 
     fun unused(decl: VarDecl): Boolean {
@@ -198,13 +200,13 @@ class CallGraph(private val program: Program) : IAstVisitor {
     }
 
     private val prefixes = listOf("p8b_", "p8v_", "p8s_", "p8c_", "p8l_", "p8_", "")
-    private fun nameInAssemblyCode(name: String, knownAsmPrefixes: List<String> = emptyList()): InlineAssembly? {
+    private fun nameInAssemblyCode(name: String, knownAsmPrefixes: List<String> = emptyList()): List<InlineAssembly> {
         if(knownAsmPrefixes.isNotEmpty())
-            return allAssemblyNodes.firstOrNull {
+            return allAssemblyNodes.filter {
                 knownAsmPrefixes.any { prefix -> prefix+name in it.names }
             }
 
-        return allAssemblyNodes.firstOrNull {
+        return allAssemblyNodes.filter {
             prefixes.any { prefix -> prefix+name in it.names }
         }
     }
diff --git a/examples/test.p8 b/examples/test.p8
index 3ec96ba43..36cd589af 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -1,8 +1,19 @@
-%import textio
-%zeropage basicsafe
-
 main {
-    sub foo() { foo() }
-    sub bar() -> ubyte { return bar() }
-    sub start() { }
+    sub foo() {
+        cx16.r0++
+    }
+    asmsub baz() {
+        %asm{{
+            jsr p8s_foo
+        }}
+    }
+    asmsub bar() {
+        %asm{{
+            inx
+            jmp p8s_foo
+        }}
+    }
+    sub start() {
+        bar()
+    }
 }