JavaScriptCore-7600.1.4.9.tar.gz

[apple/javascriptcore.git] / ftl / FTLSaveRestore.cpp

diff --git a/ftl/FTLSaveRestore.cpp b/ftl/FTLSaveRestore.cpp
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+/*
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "FTLSaveRestore.h"
+
+#if ENABLE(FTL_JIT)
+
+#include "FPRInfo.h"
+#include "GPRInfo.h"
+#include "MacroAssembler.h"
+#include "RegisterSet.h"
+
+namespace JSC { namespace FTL {
+
+static size_t bytesForGPRs()
+{
+    return MacroAssembler::numberOfRegisters() * sizeof(int64_t);
+}
+
+static size_t bytesForFPRs()
+{
+    // FIXME: It might be worthwhile saving the full state of the FP registers, at some point.
+    // Right now we don't need this since we only do the save/restore just prior to OSR exit, and
+    // OSR exit will be guaranteed to only need the double portion of the FP registers.
+    return MacroAssembler::numberOfFPRegisters() * sizeof(double);
+}
+
+size_t requiredScratchMemorySizeInBytes()
+{
+    return bytesForGPRs() + bytesForFPRs();
+}
+
+size_t offsetOfGPR(GPRReg reg)
+{
+    return MacroAssembler::registerIndex(reg) * sizeof(int64_t);
+}
+
+size_t offsetOfFPR(FPRReg reg)
+{
+    return bytesForGPRs() + MacroAssembler::fpRegisterIndex(reg) * sizeof(double);
+}
+
+size_t offsetOfReg(Reg reg)
+{
+    if (reg.isGPR())
+        return offsetOfGPR(reg.gpr());
+    return offsetOfFPR(reg.fpr());
+}
+
+namespace {
+
+struct Regs {
+    Regs()
+    {
+        special = RegisterSet::stackRegisters();
+        special.merge(RegisterSet::reservedHardwareRegisters());
+        
+        first = MacroAssembler::firstRegister();
+        while (special.get(first))
+            first = MacroAssembler::nextRegister(first);
+        second = MacroAssembler::nextRegister(first);
+        while (special.get(second))
+            second = MacroAssembler::nextRegister(second);
+    }
+    
+    RegisterSet special;
+    GPRReg first;
+    GPRReg second;
+};
+
+} // anonymous namespace
+
+void saveAllRegisters(MacroAssembler& jit, char* scratchMemory)
+{
+    Regs regs;
+    
+    // Get the first register out of the way, so that we can use it as a pointer.
+    jit.poke64(regs.first, 0);
+    jit.move(MacroAssembler::TrustedImmPtr(scratchMemory), regs.first);
+    
+    // Get all of the other GPRs out of the way.
+    for (MacroAssembler::RegisterID reg = regs.second; reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.store64(reg, MacroAssembler::Address(regs.first, offsetOfGPR(reg)));
+    }
+    
+    // Restore the first register into the second one and save it.
+    jit.peek64(regs.second, 0);
+    jit.store64(regs.second, MacroAssembler::Address(regs.first, offsetOfGPR(regs.first)));
+    
+    // Finally save all FPR's.
+    for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.storeDouble(reg, MacroAssembler::Address(regs.first, offsetOfFPR(reg)));
+    }
+}
+
+void restoreAllRegisters(MacroAssembler& jit, char* scratchMemory)
+{
+    Regs regs;
+    
+    // Give ourselves a pointer to the scratch memory.
+    jit.move(MacroAssembler::TrustedImmPtr(scratchMemory), regs.first);
+    
+    // Restore all FPR's.
+    for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = MacroAssembler::nextFPRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.loadDouble(MacroAssembler::Address(regs.first, offsetOfFPR(reg)), reg);
+    }
+    
+    for (MacroAssembler::RegisterID reg = regs.second; reg <= MacroAssembler::lastRegister(); reg = MacroAssembler::nextRegister(reg)) {
+        if (regs.special.get(reg))
+            continue;
+        jit.load64(MacroAssembler::Address(regs.first, offsetOfGPR(reg)), reg);
+    }
+    
+    jit.load64(MacroAssembler::Address(regs.first, offsetOfGPR(regs.first)), regs.first);
+}
+
+} } // namespace JSC::FTL
+
+#endif // ENABLE(FTL_JIT)
+