Skip to content

perf(lexer): gate keywordStart on the next byte for i/c tokens #223

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
guybedford merged 3 commits into from
Jul 12, 2026
+7 −5
Merged

perf(lexer): gate keywordStart on the next byte for i/c tokens #223

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
ee4ad71
perf(lexer): gate keywordStart on the next byte for i/c tokens
BridgeAR Jul 7, 2026
1559d3e
perf(lexer): compare only the 4 bytes after the import m-gate
guybedford Jul 12, 2026
c96032f
perf(lexer): narrow the class memcmp behind the l-gate too
guybedford Jul 12, 2026
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
12 changes: 7 additions & 5 deletions src/lexer.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@

// NOTE: MESSING WITH THESE REQUIRES MANUAL ASM DICTIONARY CONSTRUCTION (via lexer.emcc.js base64 decoding)
static const char16_t XPORT[] = { 'x', 'p', 'o', 'r', 't' };
static const char16_t MPORT[] = { 'm', 'p', 'o', 'r', 't' };
static const char16_t PORT[] = { 'p', 'o', 'r', 't' };
static const char16_t LASS[] = { 'l', 'a', 's', 's' };
static const char16_t ROM[] = { 'r', 'o', 'm' };
static const char16_t ETA[] = { 'e', 't', 'a' };
Expand Down Expand Up @@ -84,11 +84,11 @@ static inline __attribute__((always_inline)) bool consumeToken (char16_t ch) {
tryParseExportStatement();
break;
case 'i':
if (keywordStart(pos) && memcmp(pos + 1, &MPORT[0], 5 * 2) == 0)
if (*(pos + 1) == 'm' && keywordStart(pos) && memcmp(pos + 2, &PORT[0], 4 * 2) == 0)
tryParseImportStatement();
break;
case 'c':
if (keywordStart(pos) && memcmp(pos + 1, &LASS[0], 4 * 2) == 0 && isBrOrWs(*(pos + 5)))
if (*(pos + 1) == 'l' && keywordStart(pos) && memcmp(pos + 2, &LASS[1], 3 * 2) == 0 && isBrOrWs(*(pos + 5)))
nextBraceIsClass = true;
break;
case '(':
Expand Down Expand Up @@ -212,7 +212,7 @@ bool parse () {
}
break;
case 'i':
if (keywordStart(pos) && memcmp(pos + 1, &MPORT[0], 5 * 2) == 0)
if (*(pos + 1) == 'm' && keywordStart(pos) && memcmp(pos + 2, &PORT[0], 4 * 2) == 0)
tryParseImportStatement();
break;
case ';':
Expand Down Expand Up @@ -1071,7 +1071,9 @@ bool isWsNotBr (char16_t c) {
}

bool isBrOrWs (char16_t c) {
return c > 8 && c < 14 || c == 32 || c == 160;
// (c - 9) < 5 is the 9..13 range as one unsigned compare: fewer wasm ops than
// `c > 8 && c < 14` at every inlined copy of this hot helper.
return (char16_t)(c - 9) < 5 || c == 32 || c == 160;
}

bool isBrOrWsOrPunctuatorNotDot (char16_t c) {
Expand Down
Loading