Changeset 97025 in webkit for trunk/Source/JavaScriptCore/bytecode/ValueProfile.h

Timestamp:

Oct 9, 2011, 3:19:23 AM (14 years ago)

Author:

[email protected]

Message:

Fix value profiling in 32_64 JIT
​https://bugs.webkit.org/show_bug.cgi?id=69717

Patch by Yuqiang Xian <​[email protected]> on 2011-10-09
Reviewed by Filip Pizlo.

Current value profiling for 32_64 JIT is broken and cannot record
correct predicated types, which results in many speculation failures
in the 32_64 DFG JIT, fallbacks to baseline JIT, and re-optimizations
again and again.
With this fix 32_64 DFG JIT can demonstrate real performance gains.

• bytecode/ValueProfile.cpp:

(JSC::ValueProfile::computeStatistics):

• bytecode/ValueProfile.h:

(JSC::ValueProfile::classInfo):
(JSC::ValueProfile::numberOfSamples):
(JSC::ValueProfile::isLive):
(JSC::ValueProfile::numberOfInt32s):
(JSC::ValueProfile::numberOfDoubles):
(JSC::ValueProfile::numberOfBooleans):
(JSC::ValueProfile::dump):

Empty value check should be performed on decoded JSValue,
as for 32_64 empty value is not identical to encoded 0.

• jit/JIT.cpp:

(JSC::JIT::privateCompile):

• jit/JITInlineMethods.h:

(JSC::JIT::emitValueProfilingSite):

• jit/JITStubCall.h:

(JSC::JITStubCall::callWithValueProfiling):

Record the right profiling result for 32_64.

File:

• trunk/Source/JavaScriptCore/bytecode/ValueProfile.h (modified) (8 diffs)

trunk/Source/JavaScriptCore/bytecode/ValueProfile.h

@@ -56 +56 @@
     const ClassInfo* classInfo(unsigned bucket) const
     {
-        if (!!m_buckets[bucket]) {
-            JSValue value = JSValue::decode(m_buckets[bucket]);
+        JSValue value = JSValue::decode(m_buckets[bucket]);
+        if (!!value) {
             if (!value.isCell())
                 return 0;
@@ -69 +69 @@
         unsigned result = 0;
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] || !!m_weakBuckets[i])
+            if (!!JSValue::decode(m_buckets[i]) || !!m_weakBuckets[i])
                 result++;
         }
@@ -83 +83 @@
     {
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] || !!m_weakBuckets[i])
+            if (!!JSValue::decode(m_buckets[i]) || !!m_weakBuckets[i])
                 return true;
         }
@@ -100 +100 @@
         unsigned result = 0;
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] && JSValue::decode(m_buckets[i]).isInt32())
+            if (JSValue::decode(m_buckets[i]).isInt32())
                 result++;
         }
@@ -110 +110 @@
         unsigned result = 0;
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] && JSValue::decode(m_buckets[i]).isDouble())
+            if (JSValue::decode(m_buckets[i]).isDouble())
                 result++;
         }
@@ -171 +171 @@
         unsigned result = 0;
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] && JSValue::decode(m_buckets[i]).isBoolean())
+            if (JSValue::decode(m_buckets[i]).isBoolean())
                 result++;
         }
@@ -239 +239 @@
         bool first = true;
         for (unsigned i = 0; i < numberOfBuckets; ++i) {
-            if (!!m_buckets[i] || !!m_weakBuckets[i]) {
+            JSValue value = JSValue::decode(m_buckets[i]);
+            if (!!value || !!m_weakBuckets[i]) {
                 if (first) {
                     fprintf(out, ": ");
@@ -247 +248 @@
             }
             
-            if (!!m_buckets[i])
-                fprintf(out, "%s", JSValue::decode(m_buckets[i]).description());
+            if (!!value)
+                fprintf(out, "%s", value.description());
             
             if (!!m_weakBuckets[i])