Changeset 96563 in webkit for trunk/Source/JavaScriptCore/jit/JITStubs.cpp

Timestamp:

Oct 3, 2011, 6:16:46 PM (14 years ago)

Author:

[email protected]

Message:

On X86, switch bucketCount into a register, timeoutCheck into memory
​https://bugs.webkit.org/show_bug.cgi?id=69299

Reviewed by Geoff Garen.

We don't have sufficient registers to keep both in registers, and DFG JIT will trample esi;
it doesn't matter if the bucketCount gets stomped on (in fact it may add to randomness!),
but it if the timeoutCheck gets trashed we may make calls out to the timout_check stub
function too frequently (regressing performance). This patch has no perf impact on sunspider.

• JavaScriptCore.xcodeproj/project.pbxproj:
• assembler/MacroAssemblerX86.h:

(JSC::MacroAssemblerX86::branchAdd32):
(JSC::MacroAssemblerX86::branchSub32):

• Added branchSub32 with AbsoluteAddress.

• jit/JIT.cpp:

(JSC::JIT::emitTimeoutCheck):

• Keep timeout count in memory on X86.

• jit/JITInlineMethods.h:

(JSC::JIT::emitValueProfilingSite):

• remove X86 specific code, switch bucket count back into a register.

• jit/JITStubs.cpp:
  • Stop initializing esi (it is no longer the timeoutCheck!)
• jit/JSInterfaceJIT.h:
  • change definition of esi to be the bucketCountRegister.
• runtime/JSGlobalData.cpp:

(JSC::JSGlobalData::JSGlobalData):

• runtime/JSGlobalData.h:
  • Add timeoutCount as a property to global data (the counter should be per-thread).

File:

• trunk/Source/JavaScriptCore/jit/JITStubs.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/jit/JITStubs.cpp

@@ -132 +132 @@
     "pushl %ebx" "\n"
     "subl $0x3c, %esp" "\n"
-    "movl $512, %esi" "\n"
     "movl 0x58(%esp), %edi" "\n"
     "call *0x50(%esp)" "\n"
@@ -262 +261 @@
             push ebx;
             sub esp, 0x3c;
-            mov esi, 512;
             mov ecx, esp;
             mov edi, [esp + 0x58];