Partial strings optimization

maccasoft · Mar 27, 2023 · 8f691f4 · 8f691f4
1 parent efe9ecc
commit 8f691f4
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diff --git a/modules/spin-tools/src-tests/com/maccasoft/propeller/spin1/Spin1ObjectCompilerTest.java b/modules/spin-tools/src-tests/com/maccasoft/propeller/spin1/Spin1ObjectCompilerTest.java
@@ -2156,6 +2156,62 @@ void testOptimizeStrings() throws Exception {
             + "", compile(text, false));
     }
 
+    @Test
+    void testOptimizePartialStrings() throws Exception {
+        String text = ""
+            + "PUB main | a, b, c\n"
+            + "\n"
+            + "    a := string(\"12345678\", 13, 10)\n"
+            + "    b := \"12345678\"\n"
+            + "    c := @\"5678\"\n"
+            + "\n"
+            + "PUB setup | a, b, c\n"
+            + "\n"
+            + "    a := string(\"12345678\", 13, 10)\n"
+            + "    b := \"12345678\"\n"
+            + "    c := @\"5678\"\n"
+            + "\n"
+            + "";
+
+        Assertions.assertEquals(""
+            + "' Object header\n"
+            + "00000 00000       38 00          Object size\n"
+            + "00002 00002       03             Method count + 1\n"
+            + "00003 00003       00             Object count\n"
+            + "00004 00004       0C 00 0C 00    Function main @ $000C (local size 12)\n"
+            + "00008 00008       17 00 0C 00    Function setup @ $0017 (local size 12)\n"
+            + "' PUB main | a, b, c\n"
+            + "'     a := string(\"12345678\", 13, 10)\n"
+            + "0000C 0000C       87 80 22       MEM_ADDRESS BYTE PBASE+$0022\n"
+            + "0000F 0000F       65             VAR_WRITE LONG DBASE+$0004 (short)\n"
+            + "'     b := \"12345678\"\n"
+            + "00010 00010       87 2D          MEM_ADDRESS BYTE PBASE+$002D\n"
+            + "00012 00012       69             VAR_WRITE LONG DBASE+$0008 (short)\n"
+            + "'     c := @\"5678\"\n"
+            + "00013 00013       87 31          MEM_ADDRESS BYTE PBASE+$0031\n"
+            + "00015 00015       6D             VAR_WRITE LONG DBASE+$000C (short)\n"
+            + "00016 00016       32             RETURN\n"
+            + "' PUB setup | a, b, c\n"
+            + "'     a := string(\"12345678\", 13, 10)\n"
+            + "00017 00017       87 80 22       MEM_ADDRESS BYTE PBASE+$0022\n"
+            + "0001A 0001A       65             VAR_WRITE LONG DBASE+$0004 (short)\n"
+            + "'     b := \"12345678\"\n"
+            + "0001B 0001B       87 2D          MEM_ADDRESS BYTE PBASE+$002D\n"
+            + "0001D 0001D       69             VAR_WRITE LONG DBASE+$0008 (short)\n"
+            + "'     c := @\"5678\"\n"
+            + "0001E 0001E       87 31          MEM_ADDRESS BYTE PBASE+$0031\n"
+            + "00020 00020       6D             VAR_WRITE LONG DBASE+$000C (short)\n"
+            + "00021 00021       32             RETURN\n"
+            + "' (string data)\n"
+            + "00022 00022       31 32 33 34 35 STRING\n"
+            + "00027 00027       36 37 38 0D 0A\n"
+            + "0002C 0002C       00\n"
+            + "0002D 0002D       31 32 33 34 35 STRING\n"
+            + "00032 00032       36 37 38 00\n"
+            + "00036 00036       00 00          Padding\n"
+            + "", compile(text, false));
+    }
+
     @Test
     void testCharacterLiteral() throws Exception {
         String text = ""

diff --git a/modules/spin-tools/src/com/maccasoft/propeller/spin1/Spin1BytecodeCompiler.java b/modules/spin-tools/src/com/maccasoft/propeller/spin1/Spin1BytecodeCompiler.java
@@ -1353,7 +1353,31 @@ public Spin1Bytecode addStringData(Spin1Bytecode string) {
                     return bc;
                 }
             }
+
+            byte[] b1 = string.getBytes();
+            for (Spin1Bytecode bc : stringData) {
+                byte[] b0 = bc.getBytes();
+                if (b0.length > b1.length && Arrays.equals(b0, b0.length - b1.length, b0.length, b1, 0, b1.length)) {
+                    Spin1Context sharedContext = new Spin1Context() {
+
+                        @Override
+                        public int getObjectAddress() {
+                            return bc.getContext().getObjectAddress() + (b0.length - b1.length);
+                        }
+
+                    };
+                    return new Spin1Bytecode(sharedContext) {
+
+                        @Override
+                        public Spin1Context getContext() {
+                            return sharedContext;
+                        }
+
+                    };
+                }
+            }
         }
+
         stringData.add(string);
         return string;
     }