1 files changed, 73 insertions, 0 deletions
diff --git a/src/jit/fp.h b/src/jit/fp.h
new file mode 100644
index 0000000000..f1cee9581a
--- /dev/null
+++ b/src/jit/fp.h
@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#ifndef _JIT_FP
+
+#define _JIT_FP
+
+// Auxiliary structures.
+#if FEATURE_STACK_FP_X87
+
+enum dummyFPenum
+{
+#define REGDEF(name, rnum, mask, sname) dummmy_##name = rnum,
+#include "registerfp.h"
+
+    FP_VIRTUALREGISTERS,
+};
+
+// FlatFPStateX87 holds the state of the virtual register file. For each
+// virtual register we keep track to which physical register we're
+// mapping. We also keep track of the physical stack.
+
+#define FP_PHYSICREGISTERS FP_VIRTUALREGISTERS
+#define FP_VRNOTMAPPED -1
+
+struct FlatFPStateX87
+{
+public:
+    void Init(FlatFPStateX87* pFrom = 0);
+    bool Mapped(unsigned uEntry); // Is virtual register mapped
+    void Unmap(unsigned uEntry);  // Unmaps a virtual register
+    void Associate(unsigned uEntry, unsigned uStack);
+    unsigned StackToST(unsigned uEntry); // Maps the stack to a ST(x) entry
+    unsigned VirtualToST(unsigned uEntry);
+    unsigned STToVirtual(unsigned uST);
+    unsigned TopIndex();
+    unsigned TopVirtual();
+    void Rename(unsigned uVirtualTo, unsigned uVirtualFrom);
+    unsigned Pop();
+    void Push(unsigned uEntry);
+    bool IsEmpty();
+
+    // Debug/test methods
+    static bool AreEqual(FlatFPStateX87* pSrc, FlatFPStateX87* pDst);
+#ifdef DEBUG
+    bool IsValidEntry(unsigned uEntry);
+    bool IsConsistent();
+    void UpdateMappingFromStack();
+    void Dump();
+
+    // In some optimizations the stack will be inconsistent in some transactions. We want to keep
+    // the checks for everthing else, so if have the stack in an inconsistent state, you must
+    // ignore it on purpose.
+    bool m_bIgnoreConsistencyChecks;
+
+    inline void IgnoreConsistencyChecks(bool bIgnore)
+    {
+        m_bIgnoreConsistencyChecks = bIgnore;
+    }
+#else
+    inline void IgnoreConsistencyChecks(bool bIgnore)
+    {
+    }
+#endif
+
+    unsigned m_uVirtualMap[FP_VIRTUALREGISTERS];
+    unsigned m_uStack[FP_PHYSICREGISTERS];
+    unsigned m_uStackSize;
+};
+
+#endif // FEATURE_STACK_FP_X87
+#endif