Revert "RegExp: Do on demand JIT compilation"

This reverts commit 04820be3011395bd5cb13dea8f81c9b9bca4da8f.

Reason for revert: Caused QTBUG-121535
Fixes: QTBUG-121535
Change-Id: Ie65a98bc8dd07e836cf663695d9259014581bda6
Reviewed-by: Jani Heikkinen <jani.heikkinen@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 26 insertions, 50 deletions

diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index 1876b29c3e..be7ff77603 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -9,10 +9,6 @@
 
 using namespace QV4;
 
-#if ENABLE(YARR_JIT)
-static constexpr quint8 RegexpJitThreshold = 5;
-#endif
-
 static JSC::RegExpFlags jscFlags(uint flags)
 {
     JSC::RegExpFlags jscFlags = JSC::NoFlags;
@@ -44,51 +40,12 @@ uint RegExp::match(const QString &string, int start, uint *matchOffsets)
     if (!isValid())
         return JSC::Yarr::offsetNoMatch;
 
-#if ENABLE(YARR_JIT)
-    auto *priv = d();
-
-    auto regenerateByteCode = [](Heap::RegExp *regexp) {
-        JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
-        JSC::Yarr::YarrPattern yarrPattern(WTF::String(*regexp->pattern), jscFlags(regexp->flags),
-                                           error);
-
-        // As we successfully parsed the pattern before, we should still be able to.
-        Q_ASSERT(error == JSC::Yarr::ErrorCode::NoError);
-
-        regexp->byteCode = JSC::Yarr::byteCompile(
-                                   yarrPattern,
-                                   regexp->internalClass->engine->bumperPointerAllocator).release();
-    };
-    auto removeJitCode = [](Heap::RegExp *regexp) {
-        delete regexp->jitCode;
-        regexp->jitCode = nullptr;
-        regexp->jitFailed = true;
-    };
-    if (!(priv->jitCode || priv->jitFailed)) {
-        if (string.length() > 1024 || priv->matchCount++ == RegexpJitThreshold) {
-            auto *engine = priv->internalClass->engine;
-            if (engine->canJIT()) {
-                JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
-                JSC::Yarr::YarrPattern yarrPattern(WTF::String(*priv->pattern), jscFlags(priv->flags), error);
-                if (!yarrPattern.m_containsBackreferences) {
-                    priv->jitCode = new JSC::Yarr::YarrCodeBlock;
-                    JSC::VM *vm = static_cast<JSC::VM *>(engine);
-                    JSC::Yarr::jitCompile(yarrPattern, JSC::Yarr::Char16, vm, *priv->jitCode);
-                }
-            }
-            if (!priv->hasValidJITCode())
-                removeJitCode(priv);
-        }
-        // Note: We can't throw away the byte code as the JIT can't handle everything and
-        // might return offsetJITFail
-    }
-#endif
-
     WTF::String s(string);
 
 #if ENABLE(YARR_JIT)
+    static const uint offsetJITFail = std::numeric_limits<unsigned>::max() - 1;
+    auto *priv = d();
     if (priv->hasValidJITCode()) {
-        static const uint offsetJITFail = std::numeric_limits<unsigned>::max() - 1;
         uint ret = JSC::Yarr::offsetNoMatch;
 #if ENABLE(YARR_JIT_ALL_PARENS_EXPRESSIONS)
         char buffer[8192];
@@ -101,10 +58,19 @@ uint RegExp::match(const QString &string, int start, uint *matchOffsets)
         if (ret != offsetJITFail)
             return ret;
 
-        removeJitCode(priv);
         // JIT failed. We need byteCode to run the interpreter.
-        Q_ASSERT(!priv->byteCode);
-        regenerateByteCode(priv);
+        if (!priv->byteCode) {
+            JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
+            JSC::Yarr::YarrPattern yarrPattern(WTF::String(*priv->pattern), jscFlags(priv->flags),
+                                               error);
+
+            // As we successfully parsed the pattern before, we should still be able to.
+            Q_ASSERT(error == JSC::Yarr::ErrorCode::NoError);
+
+            priv->byteCode = JSC::Yarr::byteCompile(
+                                     yarrPattern,
+                                     priv->internalClass->engine->bumperPointerAllocator).release();
+        }
     }
 #endif // ENABLE(YARR_JIT)
 
@@ -209,15 +175,25 @@ void Heap::RegExp::init(ExecutionEngine *engine, const QString &pattern, uint fl
     this->flags = flags;
 
     valid = false;
-    jitFailed = false;
-    matchCount = 0;
 
     JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
     JSC::Yarr::YarrPattern yarrPattern(WTF::String(pattern), jscFlags(flags), error);
     if (error != JSC::Yarr::ErrorCode::NoError)
         return;
     subPatternCount = yarrPattern.m_numSubpatterns;
+#if ENABLE(YARR_JIT)
+    if (!yarrPattern.m_containsBackreferences && engine->canJIT()) {
+        jitCode = new JSC::Yarr::YarrCodeBlock;
+        JSC::VM *vm = static_cast<JSC::VM *>(engine);
+        JSC::Yarr::jitCompile(yarrPattern, JSC::Yarr::Char16, vm, *jitCode);
+    }
+#else
     Q_UNUSED(engine);
+#endif
+    if (hasValidJITCode()) {
+        valid = true;
+        return;
+    }
     byteCode = JSC::Yarr::byteCompile(yarrPattern, internalClass->engine->bumperPointerAllocator).release();
     if (byteCode)
         valid = true;