The Tor Browser: js/src/jit/BaselineFrameInfo.cpp@6474c204b198 (annotated)

js/src/jit/BaselineFrameInfo.cpp@6474c204b198 (annotated)

js/src/jit/BaselineFrameInfo.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "jit/BaselineFrameInfo.h"
 #ifdef DEBUG
 # include "jit/BytecodeAnalysis.h"
 #endif
 using namespace js;
 using namespace js::jit;
 bool
 FrameInfo::init(TempAllocator &alloc)
 {
     // One slot is always needed for this/arguments type checks.
     size_t nstack = Max(script->nslots() - script->nfixed(), size_t(1));
     if (!stack.init(alloc, nstack))
         return false;
     return true;
 }
 void
 FrameInfo::sync(StackValue *val)
 {
     switch (val->kind()) {
       case StackValue::Stack:
         break;
       case StackValue::LocalSlot:
         masm.pushValue(addressOfLocal(val->localSlot()));
         break;
       case StackValue::ArgSlot:
         masm.pushValue(addressOfArg(val->argSlot()));
         break;
       case StackValue::ThisSlot:
         masm.pushValue(addressOfThis());
         break;
       case StackValue::Register:
         masm.pushValue(val->reg());
         break;
       case StackValue::Constant:
         masm.pushValue(val->constant());
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("Invalid kind");
     }
     val->setStack();
 }
 void
 FrameInfo::syncStack(uint32_t uses)
 {
     JS_ASSERT(uses <= stackDepth());
     uint32_t depth = stackDepth() - uses;
     for (uint32_t i = 0; i < depth; i++) {
         StackValue *current = &stack[i];
         sync(current);
     }
 }
 uint32_t
 FrameInfo::numUnsyncedSlots()
 {
     // Start at the bottom, find the first value that's not synced.
     uint32_t i = 0;
     for (; i < stackDepth(); i++) {
         if (peek(-int32_t(i + 1))->kind() == StackValue::Stack)
             break;
     }
     return i;
 }
 void
 FrameInfo::popValue(ValueOperand dest)
 {
     StackValue *val = peek(-1);
     switch (val->kind()) {
       case StackValue::Constant:
         masm.moveValue(val->constant(), dest);
         break;
       case StackValue::LocalSlot:
         masm.loadValue(addressOfLocal(val->localSlot()), dest);
         break;
       case StackValue::ArgSlot:
         masm.loadValue(addressOfArg(val->argSlot()), dest);
         break;
       case StackValue::ThisSlot:
         masm.loadValue(addressOfThis(), dest);
         break;
       case StackValue::Stack:
         masm.popValue(dest);
         break;
       case StackValue::Register:
         masm.moveValue(val->reg(), dest);
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("Invalid kind");
     }
     // masm.popValue already adjusted the stack pointer, don't do it twice.
     pop(DontAdjustStack);
 }
 void
 FrameInfo::popRegsAndSync(uint32_t uses)
 {
     // x86 has only 3 Value registers. Only support 2 regs here for now,
     // so that there's always a scratch Value register for reg -> reg
     // moves.
     JS_ASSERT(uses > 0);
     JS_ASSERT(uses <= 2);
     JS_ASSERT(uses <= stackDepth());
     syncStack(uses);
     switch (uses) {
       case 1:
         popValue(R0);
         break;
       case 2: {
         // If the second value is in R1, move it to R2 so that it's not
         // clobbered by the first popValue.
         StackValue *val = peek(-2);
         if (val->kind() == StackValue::Register && val->reg() == R1) {
             masm.moveValue(R1, R2);
             val->setRegister(R2);
         }
         popValue(R1);
         popValue(R0);
         break;
       }
       default:
         MOZ_ASSUME_UNREACHABLE("Invalid uses");
     }
 }
 #ifdef DEBUG
 void
 FrameInfo::assertValidState(const BytecodeInfo &info)
 {
     // Check stack depth.
     JS_ASSERT(stackDepth() == info.stackDepth);
     // Start at the bottom, find the first value that's not synced.
     uint32_t i = 0;
     for (; i < stackDepth(); i++) {
         if (stack[i].kind() != StackValue::Stack)
             break;
     }
     // Assert all values on top of it are also not synced.
     for (; i < stackDepth(); i++)
         JS_ASSERT(stack[i].kind() != StackValue::Stack);
     // Assert every Value register is used by at most one StackValue.
     // R2 is used as scratch register by the compiler and FrameInfo,
     // so it shouldn't be used for StackValues.
     bool usedR0 = false, usedR1 = false;
     for (i = 0; i < stackDepth(); i++) {
         if (stack[i].kind() == StackValue::Register) {
             ValueOperand reg = stack[i].reg();
             if (reg == R0) {
                 JS_ASSERT(!usedR0);
                 usedR0 = true;
             } else if (reg == R1) {
                 JS_ASSERT(!usedR1);
                 usedR1 = true;
             } else {
                 MOZ_ASSUME_UNREACHABLE("Invalid register");
             }
         }
     }
 }
 #endif

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js/src/jit/BaselineFrameInfo.cpp@6474c204b198 (annotated)

js/src/jit/BaselineFrameInfo.cpp