Fix jump patching (#215)

smarr · Aug 23, 2024 · 70ce0b7 · 70ce0b7
2 parents 54f8adc + 622a8cc
commit 70ce0b7
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Showing 6 changed files with 66 additions and 84 deletions.
diff --git a/src/trufflesom/src/trufflesom/compiler/bc/BytecodeMethodGenContext.java b/src/trufflesom/src/trufflesom/compiler/bc/BytecodeMethodGenContext.java
@@ -122,6 +122,10 @@ private BytecodeMethodGenContext(final ClassGenerationContext holderGenc,
     last4Bytecodes = new byte[4];
   }
 
+  public void dump() {
+    Disassembler.dumpMethod(this);
+  }
+
   public Object getConstant(final int bytecodeIdx) {
     return literals.get(bytecode.get(bytecodeIdx + 1));
   }
@@ -174,7 +178,7 @@ public void addBytecodeArgument(final byte code) {
 
   public void patchJumpOffsetToPointToNextInstruction(final int idxOfOffset,
       final ParserBc parser) throws ParseError {
-    int instructionStart = idxOfOffset - 1;
+    final int instructionStart = idxOfOffset - 1;
     byte bytecodeBeforeOffset = bytecode.get(instructionStart);
     assert isOneOf(bytecodeBeforeOffset,
         JUMP_BYTECODES) : "Expected to patch a JUMP instruction, but got bc: "
@@ -189,10 +193,12 @@ assert isOneOf(bytecodeBeforeOffset,
       bytecode.set(idxOfOffset, (byte) jumpOffset);
       bytecode.set(idxOfOffset + 1, (byte) 0);
     } else {
-      int offsetOfBytecode = idxOfOffset - 1;
       // we need two bytes for the jump offset
-      bytecode.set(offsetOfBytecode,
-          (byte) (bytecode.get(offsetOfBytecode) + Bytecodes.NUM_1_BYTE_JUMP_BYTECODES));
+      if (bytecodeBeforeOffset < JUMP2) {
+        // we need to convert the JUMP to a JUMP2
+        bytecode.set(instructionStart,
+            (byte) (bytecodeBeforeOffset + Bytecodes.NUM_1_BYTE_JUMP_BYTECODES));
+      }
 
       byte byte1 = (byte) jumpOffset;
       byte byte2 = (byte) (jumpOffset >> 8);

diff --git a/src/trufflesom/src/trufflesom/interpreter/bc/Bytecodes.java b/src/trufflesom/src/trufflesom/interpreter/bc/Bytecodes.java
@@ -138,9 +138,9 @@ public static String getPaddedBytecodeName(final byte bytecode) {
     return PADDED_BYTECODE_NAMES[bytecode];
   }
 
-  public static final byte LEN_NO_ARG     = 1;
-  public static final byte LEN_TWO_ARGS   = 2;
-  public static final byte LEN_THREE_ARGS = 3;
+  public static final byte LEN_NO_ARG   = 1;
+  public static final byte LEN_ONE_ARG  = 2;
+  public static final byte LEN_TWO_ARGS = 3;
 
   public static int getBytecodeLength(final byte bytecode) {
     return BYTECODE_LENGTH[bytecode];