webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 100 insertions, 25 deletions

diff --git a/Source/JavaScriptCore/ftl/FTLThunks.cpp b/Source/JavaScriptCore/ftl/FTLThunks.cpp
index bf04af02a..cfbc75b7c 100644
--- a/Source/JavaScriptCore/ftl/FTLThunks.cpp
+++ b/Source/JavaScriptCore/ftl/FTLThunks.cpp
@@ -29,8 +29,10 @@
 #if ENABLE(FTL_JIT)
 
 #include "AssemblyHelpers.h"
+#include "DFGOSRExitCompilerCommon.h"
 #include "FPRInfo.h"
 #include "FTLOSRExitCompiler.h"
+#include "FTLOperations.h"
 #include "FTLSaveRestore.h"
 #include "GPRInfo.h"
 #include "LinkBuffer.h"
@@ -39,29 +41,51 @@ namespace JSC { namespace FTL {
 
 using namespace DFG;
 
-MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM& vm, const Location& location)
+enum class FrameAndStackAdjustmentRequirement {
+    Needed, 
+    NotNeeded 
+};
+
+static MacroAssemblerCodeRef genericGenerationThunkGenerator(
+    VM* vm, FunctionPtr generationFunction, const char* name, unsigned extraPopsToRestore, FrameAndStackAdjustmentRequirement frameAndStackAdjustmentRequirement)
 {
-    AssemblyHelpers jit(&vm, 0);
+    AssemblyHelpers jit(vm, 0);
+
+    if (frameAndStackAdjustmentRequirement == FrameAndStackAdjustmentRequirement::Needed) {
+        // This needs to happen before we use the scratch buffer because this function also uses the scratch buffer.
+        adjustFrameAndStackInOSRExitCompilerThunk<FTL::JITCode>(jit, vm, JITCode::FTLJIT);
+    }
     
-    // Note that the "return address" will be the OSR exit ID.
+    // Note that the "return address" will be the ID that we pass to the generation function.
+    
+    ptrdiff_t stackMisalignment = MacroAssembler::pushToSaveByteOffset();
     
     // Pretend that we're a C call frame.
-    jit.push(MacroAssembler::framePointerRegister);
+    jit.pushToSave(MacroAssembler::framePointerRegister);
     jit.move(MacroAssembler::stackPointerRegister, MacroAssembler::framePointerRegister);
-    jit.push(GPRInfo::regT0);
-    jit.push(GPRInfo::regT0);
+    stackMisalignment += MacroAssembler::pushToSaveByteOffset();
+    
+    // Now create ourselves enough stack space to give saveAllRegisters() a scratch slot.
+    unsigned numberOfRequiredPops = 0;
+    do {
+        jit.pushToSave(GPRInfo::regT0);
+        stackMisalignment += MacroAssembler::pushToSaveByteOffset();
+        numberOfRequiredPops++;
+    } while (stackMisalignment % stackAlignmentBytes());
     
-    ScratchBuffer* scratchBuffer = vm.scratchBufferForSize(requiredScratchMemorySizeInBytes());
+    ScratchBuffer* scratchBuffer = vm->scratchBufferForSize(requiredScratchMemorySizeInBytes());
     char* buffer = static_cast<char*>(scratchBuffer->dataBuffer());
     
     saveAllRegisters(jit, buffer);
     
     // Tell GC mark phase how much of the scratch buffer is active during call.
-    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::nonArgGPR1);
-    jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR1);
+    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::nonArgGPR0);
+    jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR0);
 
-    location.restoreInto(jit, buffer, GPRInfo::argumentGPR0, 1);
-    jit.peek(GPRInfo::argumentGPR1, 3);
+    jit.loadPtr(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
+    jit.peek(
+        GPRInfo::argumentGPR1,
+        (stackMisalignment - MacroAssembler::pushToSaveByteOffset()) / sizeof(void*));
     MacroAssembler::Call functionCall = jit.call();
     
     // At this point we want to make a tail call to what was returned to us in the
@@ -71,24 +95,73 @@ MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM& vm, const Location& lo
     
     jit.move(GPRInfo::returnValueGPR, GPRInfo::regT0);
     
-    // Prepare for tail call.
-    jit.pop(GPRInfo::regT1);
-    jit.pop(GPRInfo::regT1);
-    jit.pop(MacroAssembler::framePointerRegister);
-    
-    // At this point we're sitting on the return address - so if we did a jump right now, the
-    // tail-callee would be happy. Instead we'll stash the callee in the return address and then
-    // restore all registers.
+    // Make sure we tell the GC that we're not using the scratch buffer anymore.
+    jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->activeLengthPtr()), GPRInfo::regT1);
+    jit.storePtr(MacroAssembler::TrustedImmPtr(0), GPRInfo::regT1);
     
+    // Prepare for tail call.
+    while (numberOfRequiredPops--)
+        jit.popToRestore(GPRInfo::regT1);
+    jit.popToRestore(MacroAssembler::framePointerRegister);
+
+    // When we came in here, there was an additional thing pushed to the stack. Some clients want it
+    // popped before proceeding.
+    while (extraPopsToRestore--)
+        jit.popToRestore(GPRInfo::regT1);
+
+    // Put the return address wherever the return instruction wants it. On all platforms, this
+    // ensures that the return address is out of the way of register restoration.
     jit.restoreReturnAddressBeforeReturn(GPRInfo::regT0);
-    
+
     restoreAllRegisters(jit, buffer);
 
     jit.ret();
     
-    LinkBuffer patchBuffer(vm, &jit, GLOBAL_THUNK_ID);
-    patchBuffer.link(functionCall, compileFTLOSRExit);
-    return FINALIZE_CODE(patchBuffer, ("FTL OSR exit generation thunk for callFrame at %s", toCString(location).data()));
+    LinkBuffer patchBuffer(*vm, jit, GLOBAL_THUNK_ID);
+    patchBuffer.link(functionCall, generationFunction);
+    return FINALIZE_CODE(patchBuffer, ("%s", name));
+}
+
+MacroAssemblerCodeRef osrExitGenerationThunkGenerator(VM* vm)
+{
+    unsigned extraPopsToRestore = 0;
+    return genericGenerationThunkGenerator(
+        vm, compileFTLOSRExit, "FTL OSR exit generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::Needed);
+}
+
+MacroAssemblerCodeRef lazySlowPathGenerationThunkGenerator(VM* vm)
+{
+    unsigned extraPopsToRestore = 1;
+    return genericGenerationThunkGenerator(
+        vm, compileFTLLazySlowPath, "FTL lazy slow path generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::NotNeeded);
+}
+
+static void registerClobberCheck(AssemblyHelpers& jit, RegisterSet dontClobber)
+{
+    if (!Options::clobberAllRegsInFTLICSlowPath())
+        return;
+    
+    RegisterSet clobber = RegisterSet::allRegisters();
+    clobber.exclude(RegisterSet::reservedHardwareRegisters());
+    clobber.exclude(RegisterSet::stackRegisters());
+    clobber.exclude(RegisterSet::calleeSaveRegisters());
+    clobber.exclude(dontClobber);
+    
+    GPRReg someGPR;
+    for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
+        if (!clobber.get(reg) || !reg.isGPR())
+            continue;
+        
+        jit.move(AssemblyHelpers::TrustedImm32(0x1337beef), reg.gpr());
+        someGPR = reg.gpr();
+    }
+    
+    for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
+        if (!clobber.get(reg) || !reg.isFPR())
+            continue;
+        
+        jit.move64ToDouble(someGPR, reg.fpr());
+    }
 }
 
 MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey& key)
@@ -122,8 +195,10 @@ MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey&
     jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR0);
     jit.storePtr(GPRInfo::nonArgGPR0, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()));
     
-    JITCompiler::Call call = jit.call();
+    registerClobberCheck(jit, key.argumentRegisters());
     
+    AssemblyHelpers::Call call = jit.call();
+
     jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()), GPRInfo::nonPreservedNonReturnGPR);
     jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);
     
@@ -147,7 +222,7 @@ MacroAssemblerCodeRef slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey&
     
     jit.ret();
 
-    LinkBuffer patchBuffer(vm, &jit, GLOBAL_THUNK_ID);
+    LinkBuffer patchBuffer(vm, jit, GLOBAL_THUNK_ID);
     patchBuffer.link(call, FunctionPtr(key.callTarget()));
     return FINALIZE_CODE(patchBuffer, ("FTL slow path call thunk for %s", toCString(key).data()));
 }