Changeset 194786 in webkit

Timestamp:

Jan 8, 2016, 1:42:23 PM (10 years ago)

Author:

fpizlo@apple.com

Message:

FTL B3 compile() doesn't clear exception handlers before we add FTL-specific ones
​https://bugs.webkit.org/show_bug.cgi?id=152922

Reviewed by Saam Barati.

FTL B3 was generating a handler table that first contained the old baseline handlers keyed
by baseline's bytecode indices and then the FTL handlers keyed by FTL callsite index. That's
wrong, since the FTL code block should not contain any baseline handlers. The fix is to
clear the handlers before generation, sort of like FTL LLVM does.

Also added some stuff to make it easier to inspect the handler table.

This reduces the numbe rof failures from 25 to 13.

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::dumpBytecode):
(JSC::CodeBlock::dumpExceptionHandlers):
(JSC::CodeBlock::beginDumpProfiling):

• bytecode/CodeBlock.h:
• ftl/FTLB3Compile.cpp:

(JSC::FTL::compile):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• bytecode/CodeBlock.cpp (modified) (2 diffs)
• bytecode/CodeBlock.h (modified) (1 diff)
• ftl/FTLB3Compile.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2016-01-08  Filip Pizlo  <fpizlo@apple.com>
+
+        FTL B3 compile() doesn't clear exception handlers before we add FTL-specific ones
+        https://bugs.webkit.org/show_bug.cgi?id=152922
+
+        Reviewed by Saam Barati.
+
+        FTL B3 was generating a handler table that first contained the old baseline handlers keyed
+        by baseline's bytecode indices and then the FTL handlers keyed by FTL callsite index. That's
+        wrong, since the FTL code block should not contain any baseline handlers. The fix is to
+        clear the handlers before generation, sort of like FTL LLVM does.
+
+        Also added some stuff to make it easier to inspect the handler table.
+
+        This reduces the numbe rof failures from 25 to 13.
+
+        * bytecode/CodeBlock.cpp:
+        (JSC::CodeBlock::dumpBytecode):
+        (JSC::CodeBlock::dumpExceptionHandlers):
+        (JSC::CodeBlock::beginDumpProfiling):
+        * bytecode/CodeBlock.h:
+        * ftl/FTLB3Compile.cpp:
+        (JSC::FTL::compile):
+
 2016-01-08  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -640 +640 @@
     }
 
-    if (m_rareData && !m_rareData->m_exceptionHandlers.isEmpty()) {
-        out.printf("\nException Handlers:\n");
-        unsigned i = 0;
-        do {
-            HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
-            out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] } %s\n",
-                i + 1, handler.start, handler.end, handler.target, handler.typeName());
-            ++i;
-        } while (i < m_rareData->m_exceptionHandlers.size());
-    }
+    dumpExceptionHandlers(out);
     
     if (m_rareData && !m_rareData->m_switchJumpTables.isEmpty()) {
@@ -694 +685 @@
 
     out.printf("\n");
+}
+
+void CodeBlock::dumpExceptionHandlers(PrintStream& out)
+{
+    if (m_rareData && !m_rareData->m_exceptionHandlers.isEmpty()) {
+        out.printf("\nException Handlers:\n");
+        unsigned i = 0;
+        do {
+            HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
+            out.printf("\t %d: { start: [%4d] end: [%4d] target: [%4d] } %s\n",
+                i + 1, handler.start, handler.end, handler.target, handler.typeName());
+            ++i;
+        } while (i < m_rareData->m_exceptionHandlers.size());
+    }
 }
 

trunk/Source/JavaScriptCore/bytecode/CodeBlock.h

@@ -193 +193 @@
         PrintStream&, unsigned bytecodeOffset,
         const StubInfoMap& = StubInfoMap(), const CallLinkInfoMap& = CallLinkInfoMap());
+    void dumpExceptionHandlers(PrintStream&);
     void printStructures(PrintStream&, const Instruction*);
     void printStructure(PrintStream&, const char* name, const Instruction*, int operand);

trunk/Source/JavaScriptCore/ftl/FTLB3Compile.cpp

@@ -110 +110 @@
     }
 
+    // We will add exception handlers while generating.
+    codeBlock->clearExceptionHandlers();
+
     CCallHelpers jit(&vm, codeBlock);
     B3::generate(*state.proc, jit);