Skip to content

Interpreter improvements: extract opcodes, arrow syntax, simplify LOAD_STRING #275

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
fglock merged 1 commit into from
Mar 6, 2026
Merged

Interpreter improvements: extract opcodes, arrow syntax, simplify LOAD_STRING #275

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 2 additions & 15 deletions src/main/java/org/perlonjava/backend/bytecode/BytecodeInterpreter.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -229,26 +229,13 @@ public static RuntimeList execute(InterpretedCode code, RuntimeArray args, int c
case Opcodes.LOAD_STRING -> {
int rd = bytecode[pc++];
int strIndex = bytecode[pc++];
String s = code.stringPool[strIndex];
RuntimeBase existing = registers[rd];
if (!(existing instanceof RuntimeScalar rs
&& rs.type == RuntimeScalarType.STRING
&& s.equals(rs.value))) {
registers[rd] = new RuntimeScalar(s);
}
registers[rd] = new RuntimeScalar(code.stringPool[strIndex]);
}

case Opcodes.LOAD_BYTE_STRING -> {
int rd = bytecode[pc++];
int strIndex = bytecode[pc++];
String s = code.stringPool[strIndex];
RuntimeBase existing = registers[rd];
if (existing instanceof RuntimeScalar rs
&& rs.type == RuntimeScalarType.BYTE_STRING
&& s.equals(rs.value)) {
break;
}
RuntimeScalar bs = new RuntimeScalar(s);
RuntimeScalar bs = new RuntimeScalar(code.stringPool[strIndex]);
bs.type = RuntimeScalarType.BYTE_STRING;
registers[rd] = bs;
}
Expand Down
7 changes: 5 additions & 2 deletions src/main/java/org/perlonjava/backend/bytecode/Opcodes.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1803,8 +1803,11 @@ public class Opcodes {
public static final short SET_FROM_LIST = 371;

/**
* Load byte string: rd = new RuntimeScalar(stringPool[index]) with BYTE_STRING type.
* Used for string literals under `no utf8` (the default).
* Load a non-UTF-8 string constant into a register.
* Creates a RuntimeScalar with BYTE_STRING type (Perl's default string encoding,
* equivalent to Latin-1/ISO-8859-1). This is the most common opcode in typical
* Perl programs — it loads hash keys, string literals, and identifiers.
* Compare with LOAD_STRING which loads UTF-8 flagged strings (from `use utf8` scope).
* Format: LOAD_BYTE_STRING rd strIndex
*/
public static final short LOAD_BYTE_STRING = 372;
Expand Down