Changeset 44838 in webkit for trunk/JavaScriptCore/jit/JITOpcodes.cpp

Timestamp:

Jun 18, 2009, 7:32:29 PM (16 years ago)

Author:

[email protected]

Message:

2009-06-18 Gavin Barraclough <​[email protected]>

Rubber Stamped by Mark Rowe (originally reviewed by Sam Weinig).

(Reintroducing patch added in r44492, and reverted in r44796.)

Change the implementation of op_throw so the stub function always modifies its
return address - if it doesn't find a 'catch' it will switch to a trampoline
to force a return from JIT execution. This saves memory, by avoiding the need
for a unique return for every op_throw.

• jit/JITOpcodes.cpp: (JSC::JIT::emit_op_throw):

JITStubs::cti_op_throw now always changes its return address,
remove return code generated after the stub call (this is now
handled by ctiOpThrowNotCaught).

• jit/JITStubs.cpp: (JSC::):

Add ctiOpThrowNotCaught definitions.

(JSC::JITStubs::DEFINE_STUB_FUNCTION):

Change cti_op_throw to always change its return address.

• jit/JITStubs.h:

Add ctiOpThrowNotCaught declaration.

File:

• trunk/JavaScriptCore/jit/JITOpcodes.cpp (modified) (1 diff)

trunk/JavaScriptCore/jit/JITOpcodes.cpp

@@ -623 +623 @@
     stubCall.call();
     ASSERT(regT0 == returnValueRegister);
-#if PLATFORM(X86_64)
-    addPtr(Imm32(0x48), X86::esp);
-    pop(X86::ebx);
-    pop(X86::r15);
-    pop(X86::r14);
-    pop(X86::r13);
-    pop(X86::r12);
-    pop(X86::ebp);
-    ret();
-#else
-    addPtr(Imm32(0x1c), X86::esp);
-    pop(X86::ebx);
-    pop(X86::edi);
-    pop(X86::esi);
-    pop(X86::ebp);
-    ret();
+#ifndef NDEBUG
+    // cti_op_throw always changes it's return address,
+    // this point in the code should never be reached.
+    breakpoint();
 #endif
 }