1 files changed, 196 insertions, 0 deletions
diff --git a/js/src/jit/BaselineFrameInfo.cpp b/js/src/jit/BaselineFrameInfo.cpp
new file mode 100644
index 000000000..9b9b991b6
--- /dev/null
+++ b/js/src/jit/BaselineFrameInfo.cpp
@@ -0,0 +1,196 @@
+/* -*- 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
+
+#include "jit/BaselineFrameInfo-inl.h"
+#include "jit/MacroAssembler-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+bool
+FrameInfo::init(TempAllocator& alloc)
+{
+    // An extra slot is needed for global scopes because INITGLEXICAL (stack
+    // depth 1) is compiled as a SETPROP (stack depth 2) on the global lexical
+    // scope.
+    size_t extra = script->isGlobalCode() ? 1 : 0;
+    size_t nstack = Max(script->nslots() - script->nfixed(), size_t(MinJITStackSize)) + extra;
+    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::EvalNewTargetSlot:
+        MOZ_ASSERT(script->isForEval());
+        masm.pushValue(addressOfEvalNewTarget());
+        break;
+      case StackValue::Register:
+        masm.pushValue(val->reg());
+        break;
+      case StackValue::Constant:
+        masm.pushValue(val->constant());
+        break;
+      default:
+        MOZ_CRASH("Invalid kind");
+    }
+
+    val->setStack();
+}
+
+void
+FrameInfo::syncStack(uint32_t uses)
+{
+    MOZ_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::EvalNewTargetSlot:
+        masm.loadValue(addressOfEvalNewTarget(), dest);
+        break;
+      case StackValue::Stack:
+        masm.popValue(dest);
+        break;
+      case StackValue::Register:
+        masm.moveValue(val->reg(), dest);
+        break;
+      default:
+        MOZ_CRASH("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.
+    MOZ_ASSERT(uses > 0);
+    MOZ_ASSERT(uses <= 2);
+    MOZ_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_CRASH("Invalid uses");
+    }
+}
+
+#ifdef DEBUG
+void
+FrameInfo::assertValidState(const BytecodeInfo& info)
+{
+    // Check stack depth.
+    MOZ_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++)
+        MOZ_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) {
+                MOZ_ASSERT(!usedR0);
+                usedR0 = true;
+            } else if (reg == R1) {
+                MOZ_ASSERT(!usedR1);
+                usedR1 = true;
+            } else {
+                MOZ_CRASH("Invalid register");
+            }
+        }
+    }
+}
+#endif