FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/compiler/aslopt.c

     /******************************************************************************
      *
      * Module Name: aslopt- Compiler optimizations
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
      * 1. Copyright Notice
     *
     * Some or all of this work - Copyright (c) 1999 - 2022, Intel Corp.
     * All rights reserved.
     *
     * 2. License
     *
     * 2.1. This is your license from Intel Corp. under its intellectual property
     * rights. You may have additional license terms from the party that provided
     * you this software, covering your right to use that party's intellectual
     * property rights.
     *
     * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
     * copy of the source code appearing in this file ("Covered Code") an
     * irrevocable, perpetual, worldwide license under Intel's copyrights in the
     * base code distributed originally by Intel ("Original Intel Code") to copy,
     * make derivatives, distribute, use and display any portion of the Covered
     * Code in any form, with the right to sublicense such rights; and
     *
     * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
     * license (with the right to sublicense), under only those claims of Intel
     * patents that are infringed by the Original Intel Code, to make, use, sell,
     * offer to sell, and import the Covered Code and derivative works thereof
     * solely to the minimum extent necessary to exercise the above copyright
     * license, and in no event shall the patent license extend to any additions
     * to or modifications of the Original Intel Code. No other license or right
     * is granted directly or by implication, estoppel or otherwise;
     *
     * The above copyright and patent license is granted only if the following
     * conditions are met:
     *
     * 3. Conditions
     *
     * 3.1. Redistribution of Source with Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification with rights to further distribute source must include
     * the above Copyright Notice, the above License, this list of Conditions,
     * and the following Disclaimer and Export Compliance provision. In addition,
     * Licensee must cause all Covered Code to which Licensee contributes to
     * contain a file documenting the changes Licensee made to create that Covered
     * Code and the date of any change. Licensee must include in that file the
     * documentation of any changes made by any predecessor Licensee. Licensee
     * must include a prominent statement that the modification is derived,
     * directly or indirectly, from Original Intel Code.
     *
     * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification without rights to further distribute source must
     * include the following Disclaimer and Export Compliance provision in the
     * documentation and/or other materials provided with distribution. In
     * addition, Licensee may not authorize further sublicense of source of any
     * portion of the Covered Code, and must include terms to the effect that the
     * license from Licensee to its licensee is limited to the intellectual
     * property embodied in the software Licensee provides to its licensee, and
     * not to intellectual property embodied in modifications its licensee may
     * make.
     *
     * 3.3. Redistribution of Executable. Redistribution in executable form of any
     * substantial portion of the Covered Code or modification must reproduce the
     * above Copyright Notice, and the following Disclaimer and Export Compliance
     * provision in the documentation and/or other materials provided with the
     * distribution.
     *
     * 3.4. Intel retains all right, title, and interest in and to the Original
     * Intel Code.
     *
     * 3.5. Neither the name Intel nor any other trademark owned or controlled by
     * Intel shall be used in advertising or otherwise to promote the sale, use or
     * other dealings in products derived from or relating to the Covered Code
     * without prior written authorization from Intel.
     *
     * 4. Disclaimer and Export Compliance
     *
     * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
     * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
     * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
     * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
     * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
     * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
     * PARTICULAR PURPOSE.
     *
     * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
     * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
     * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
     * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
     * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
     * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
     * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
     * LIMITED REMEDY.
     *
     * 4.3. Licensee shall not export, either directly or indirectly, any of this
    * software or system incorporating such software without first obtaining any
    * required license or other approval from the U. S. Department of Commerce or
    * any other agency or department of the United States Government. In the
    * event Licensee exports any such software from the United States or
    * re-exports any such software from a foreign destination, Licensee shall
    * ensure that the distribution and export/re-export of the software is in
    * compliance with all laws, regulations, orders, or other restrictions of the
    * U.S. Export Administration Regulations. Licensee agrees that neither it nor
    * any of its subsidiaries will export/re-export any technical data, process,
    * software, or service, directly or indirectly, to any country for which the
    * United States government or any agency thereof requires an export license,
    * other governmental approval, or letter of assurance, without first obtaining
    * such license, approval or letter.
    *
    *****************************************************************************
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * following license:
    *
    * 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,
    *    without modification.
    * 2. Redistributions in binary form must reproduce at minimum a disclaimer
    *    substantially similar to the "NO WARRANTY" disclaimer below
    *    ("Disclaimer") and any redistribution must be conditioned upon
    *    including a substantially similar Disclaimer requirement for further
    *    binary redistribution.
    * 3. Neither the names of the above-listed copyright holders nor the names
    *    of any contributors may be used to endorse or promote products derived
    *    from this software without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    * "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 THE COPYRIGHT
    * OWNER 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.
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * GNU General Public License ("GPL") version 2 as published by the Free
    * Software Foundation.
    *
    *****************************************************************************/
   
   #include <contrib/dev/acpica/compiler/aslcompiler.h>
   #include "aslcompiler.y.h"
   
   #include <contrib/dev/acpica/include/acparser.h>
   #include <contrib/dev/acpica/include/amlcode.h>
   #include <contrib/dev/acpica/include/acnamesp.h>
   
   
   #define _COMPONENT          ACPI_COMPILER
           ACPI_MODULE_NAME    ("aslopt")
   
   
   static UINT32               OptTotal = 0;
   
   /* Local prototypes */
   
   static ACPI_STATUS
   OptSearchToRoot (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       ACPI_BUFFER             *TargetPath,
       char                    **NewPath);
   
   static ACPI_STATUS
   OptBuildShortestPath (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       ACPI_BUFFER             *CurrentPath,
       ACPI_BUFFER             *TargetPath,
       ACPI_SIZE               AmlNameStringLength,
       UINT8                   IsDeclaration,
       char                    **ReturnNewPath);
   
   static ACPI_STATUS
   OptOptimizeNameDeclaration (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       char                    *AmlNameString,
       char                    **NewPath);
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OptSearchToRoot
    *
    * PARAMETERS:  Op                  - Current parser op
    *              WalkState           - Current state
    *              CurrentNode         - Where we are in the namespace
    *              TargetNode          - Node to which we are referring
    *              TargetPath          - External full path to the target node
    *              NewPath             - Where the optimized path is returned
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Attempt to optimize a reference to a single 4-character ACPI
    *              name utilizing the search-to-root name resolution algorithm
    *              that is used by AML interpreters.
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OptSearchToRoot (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       ACPI_BUFFER             *TargetPath,
       char                    **NewPath)
   {
       ACPI_NAMESPACE_NODE     *Node;
       ACPI_GENERIC_STATE      ScopeInfo;
       ACPI_STATUS             Status;
       char                    *Path;
   
   
       ACPI_FUNCTION_NAME (OptSearchToRoot);
   
   
       /*
        * Check if search-to-root can be utilized. Use the last NameSeg of
        * the NamePath and 1) See if can be found and 2) If found, make
        * sure that it is the same node that we want. If there is another
        * name in the search path before the one we want, the nodes will
        * not match, and we cannot use this optimization.
        */
       Path = &(((char *) TargetPath->Pointer)[
           TargetPath->Length - ACPI_NAMESEG_SIZE]);
       ScopeInfo.Scope.Node = CurrentNode;
   
       /* Lookup the NameSeg using SEARCH_PARENT (search-to-root) */
   
       Status = AcpiNsLookup (&ScopeInfo, Path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
           ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
           WalkState, &(Node));
       if (ACPI_FAILURE (Status))
       {
           return (Status);
       }
   
       /*
        * We found the name, but we must check to make sure that the node
        * matches. Otherwise, there is another identical name in the search
        * path that precludes the use of this optimization.
        */
       if (Node != TargetNode)
       {
           /*
            * This means that another object with the same name was found first,
            * and we cannot use this optimization.
            */
           return (AE_NOT_FOUND);
       }
   
       /* Found the node, we can use this optimization */
   
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
           "NAMESEG:   %-24s", Path));
   
       /* We must allocate a new string for the name (TargetPath gets deleted) */
   
       *NewPath = UtLocalCacheCalloc (ACPI_NAMESEG_SIZE + 1);
       strcpy (*NewPath, Path);
   
       if (strncmp (*NewPath, "_T_", 3))
       {
           AslError (ASL_OPTIMIZATION, ASL_MSG_SINGLE_NAME_OPTIMIZATION,
               Op, *NewPath);
       }
   
       return (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OptBuildShortestPath
    *
    * PARAMETERS:  Op                  - Current parser op
    *              WalkState           - Current state
    *              CurrentNode         - Where we are in the namespace
    *              TargetNode          - Node to which we are referring
    *              CurrentPath         - External full path to the current node
    *              TargetPath          - External full path to the target node
    *              AmlNameStringLength - Length of the original namepath
    *              IsDeclaration       - TRUE for declaration, FALSE for reference
    *              ReturnNewPath       - Where the optimized path is returned
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Build an optimal NamePath using carats
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OptBuildShortestPath (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       ACPI_BUFFER             *CurrentPath,
       ACPI_BUFFER             *TargetPath,
       ACPI_SIZE               AmlNameStringLength,
       UINT8                   IsDeclaration,
       char                    **ReturnNewPath)
   {
       UINT32                  NumCommonSegments;
       UINT32                  MaxCommonSegments;
       UINT32                  Index;
       UINT32                  NumCarats;
       UINT32                  i;
       char                    *NewPathInternal;
       char                    *NewPathExternal;
       ACPI_NAMESPACE_NODE     *Node;
       ACPI_GENERIC_STATE      ScopeInfo;
       ACPI_STATUS             Status;
       BOOLEAN                 SubPath = FALSE;
   
   
       ACPI_FUNCTION_NAME (OptBuildShortestPath);
   
   
       ScopeInfo.Scope.Node = CurrentNode;
   
       /*
        * Determine the maximum number of NameSegs that the Target and Current paths
        * can possibly have in common. (To optimize, we have to have at least 1)
        *
        * Note: The external NamePath string lengths are always a multiple of 5
        * (ACPI_NAMESEG_SIZE + separator)
        */
       MaxCommonSegments = TargetPath->Length / ACPI_PATH_SEGMENT_LENGTH;
       if (CurrentPath->Length < TargetPath->Length)
       {
           MaxCommonSegments = CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH;
       }
   
       /*
        * Determine how many NameSegs the two paths have in common.
        * (Starting from the root)
        */
       for (NumCommonSegments = 0;
            NumCommonSegments < MaxCommonSegments;
            NumCommonSegments++)
       {
           /* Compare two single NameSegs */
   
           Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1;
   
           if (!ACPI_COMPARE_NAMESEG (
               &(ACPI_CAST_PTR (char, TargetPath->Pointer)) [Index],
               &(ACPI_CAST_PTR (char, CurrentPath->Pointer)) [Index]))
           {
               /* Mismatch */
   
               break;
           }
       }
   
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " COMMON: %u",
           NumCommonSegments));
   
       /* There must be at least 1 common NameSeg in order to optimize */
   
       if (NumCommonSegments == 0)
       {
           return (AE_NOT_FOUND);
       }
   
       if (NumCommonSegments == MaxCommonSegments)
       {
           if (CurrentPath->Length == TargetPath->Length)
           {
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SAME PATH"));
               return (AE_NOT_FOUND);
           }
           else
           {
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " SUBPATH"));
               SubPath = TRUE;
           }
       }
   
       /* Determine how many prefix Carats are required */
   
       NumCarats = (CurrentPath->Length / ACPI_PATH_SEGMENT_LENGTH) -
           NumCommonSegments;
   
       /*
        * Construct a new target string
        */
       NewPathExternal =
           UtLocalCacheCalloc (TargetPath->Length + NumCarats + 1);
   
       /* Insert the Carats into the Target string */
   
       for (i = 0; i < NumCarats; i++)
       {
           NewPathExternal[i] = AML_PARENT_PREFIX;
       }
   
       /*
        * Copy only the necessary (optimal) segments from the original
        * target string
        */
       Index = (NumCommonSegments * ACPI_PATH_SEGMENT_LENGTH) + 1;
   
       /* Special handling for exact subpath in a name declaration */
   
       if (IsDeclaration && SubPath &&
           (CurrentPath->Length > TargetPath->Length))
       {
           /*
            * The current path is longer than the target, and the target is a
            * subpath of the current path. We must include one more NameSeg of
            * the target path
            */
           Index -= ACPI_PATH_SEGMENT_LENGTH;
   
           /* Special handling for Scope() operator */
   
           if (Op->Asl.AmlOpcode == AML_SCOPE_OP)
           {
               NewPathExternal[i] = AML_PARENT_PREFIX;
               i++;
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "(EXTRA ^)"));
           }
       }
   
       /* Make sure we haven't gone off the end of the target path */
   
       if (Index > TargetPath->Length)
       {
           Index = TargetPath->Length;
       }
   
       strcpy (&NewPathExternal[i],
           &(ACPI_CAST_PTR (char, TargetPath->Pointer))[Index]);
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " %-24s", NewPathExternal));
   
       /*
        * Internalize the new target string and check it against the original
        * string to make sure that this is in fact an optimization. If the
        * original string is already optimal, there is no point in continuing.
        */
       Status = AcpiNsInternalizeName (NewPathExternal, &NewPathInternal);
       if (ACPI_FAILURE (Status))
       {
           AslCoreSubsystemError (Op, Status, "Internalizing new NamePath",
               ASL_NO_ABORT);
           goto Cleanup;
       }
   
       if (strlen (NewPathInternal) >= AmlNameStringLength)
       {
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
               " NOT SHORTER (New %u old %u)",
               (UINT32) strlen (NewPathInternal),
               (UINT32) AmlNameStringLength));
   
           ACPI_FREE (NewPathInternal);
           Status = AE_NOT_FOUND;
           goto Cleanup;
       }
   
       /*
        * Check to make sure that the optimization finds the node we are
        * looking for. This is simply a sanity check on the new
        * path that has been created.
        */
       Status = AcpiNsLookup (&ScopeInfo, NewPathInternal,
           ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
           ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node));
       if (ACPI_SUCCESS (Status))
       {
           /* Found the namepath, but make sure the node is correct */
   
           if (Node == TargetNode)
           {
               /* The lookup matched the node, accept this optimization */
   
               AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION,
                   Op, NewPathExternal);
               *ReturnNewPath = NewPathInternal;
           }
           else
           {
               /* Node is not correct, do not use this optimization */
   
               Status = AE_NOT_FOUND;
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** WRONG NODE"));
               AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op,
                   "Not using optimized name - found wrong node");
           }
       }
       else
       {
           /* The lookup failed, we obviously cannot use this optimization */
   
           ACPI_FREE (NewPathInternal);
   
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ***** NOT FOUND"));
           AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op,
               "Not using optimized name - did not find node");
       }
   
   Cleanup:
   
       return (Status);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OptOptimizeNameDeclaration
    *
    * PARAMETERS:  Op                  - Current parser op
    *              WalkState           - Current state
    *              CurrentNode         - Where we are in the namespace
    *              AmlNameString       - Unoptimized namepath
    *              NewPath             - Where the optimized path is returned
    *
    * RETURN:      Status. AE_OK If path is optimized
    *
    * DESCRIPTION: Perform a simple optimization of removing an extraneous
    *              backslash prefix if we are already at the root scope.
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OptOptimizeNameDeclaration (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState,
       ACPI_NAMESPACE_NODE     *CurrentNode,
       ACPI_NAMESPACE_NODE     *TargetNode,
       char                    *AmlNameString,
       char                    **NewPath)
   {
       ACPI_STATUS             Status;
       char                    *NewPathExternal;
       ACPI_NAMESPACE_NODE     *Node;
   
   
       ACPI_FUNCTION_TRACE (OptOptimizeNameDeclaration);
   
   
       if (((CurrentNode == AcpiGbl_RootNode) ||
           (Op->Common.Parent->Asl.ParseOpcode == PARSEOP_DEFINITION_BLOCK)) &&
               (ACPI_IS_ROOT_PREFIX (AmlNameString[0])))
       {
           /*
            * The current scope is the root, and the namepath has a root prefix
            * that is therefore extraneous. Remove it.
            */
           *NewPath = &AmlNameString[1];
   
           /* Debug output */
   
           Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, *NewPath,
               NULL, &NewPathExternal);
           if (ACPI_FAILURE (Status))
           {
               AslCoreSubsystemError (Op, Status, "Externalizing NamePath",
                   ASL_NO_ABORT);
               return (Status);
           }
   
           /*
            * Check to make sure that the optimization finds the node we are
            * looking for. This is simply a sanity check on the new
            * path that has been created.
            *
            * We know that we are at the root, so NULL is used for the scope.
            */
           Status = AcpiNsLookup (NULL, *NewPath,
               ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
               ACPI_NS_DONT_OPEN_SCOPE, WalkState, &(Node));
           if (ACPI_SUCCESS (Status))
           {
               /* Found the namepath, but make sure the node is correct */
   
               if (Node == TargetNode)
               {
                   /* The lookup matched the node, accept this optimization */
   
                   AslError (ASL_OPTIMIZATION, ASL_MSG_NAME_OPTIMIZATION,
                       Op, NewPathExternal);
   
                   ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
                       "AT ROOT:   %-24s", NewPathExternal));
               }
               else
               {
                   /* Node is not correct, do not use this optimization */
   
                   Status = AE_NOT_FOUND;
                   ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
                       " ***** WRONG NODE"));
                   AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op,
                       "Not using optimized name - found wrong node");
               }
           }
           else
           {
               /* The lookup failed, we obviously cannot use this optimization */
   
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
                   " ***** NOT FOUND"));
               AslError (ASL_WARNING, ASL_MSG_COMPILER_INTERNAL, Op,
                   "Not using optimized name - did not find node");
           }
   
           ACPI_FREE (NewPathExternal);
           return (Status);
       }
   
       /* Could not optimize */
   
       return (AE_NOT_FOUND);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OptOptimizeNamePath
    *
    * PARAMETERS:  Op                  - Current parser op
    *              Flags               - Opcode info flags
    *              WalkState           - Current state
    *              AmlNameString       - Unoptimized namepath
    *              TargetNode          - Node to which AmlNameString refers
    *
    * RETURN:      None. If path is optimized, the Op is updated with new path
    *
    * DESCRIPTION: Optimize a Named Declaration or Reference to the minimal length.
    *              Must take into account both the current location in the
    *              namespace and the actual reference path.
    *
    ******************************************************************************/
   
   void
   OptOptimizeNamePath (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Flags,
       ACPI_WALK_STATE         *WalkState,
       char                    *AmlNameString,
       ACPI_NAMESPACE_NODE     *TargetNode)
   {
       ACPI_STATUS             Status;
       ACPI_BUFFER             TargetPath;
       ACPI_BUFFER             CurrentPath;
       ACPI_SIZE               AmlNameStringLength;
       ACPI_NAMESPACE_NODE     *CurrentNode;
       char                    *ExternalNameString;
       char                    *NewPath = NULL;
       ACPI_SIZE               HowMuchShorter;
       ACPI_PARSE_OBJECT       *NextOp;
   
   
       ACPI_FUNCTION_TRACE (OptOptimizeNamePath);
   
   
       /* This is an optional optimization */
   
       if (!AslGbl_ReferenceOptimizationFlag)
       {
           return_VOID;
       }
   
       /* Various required items */
   
       if (!TargetNode || !WalkState || !AmlNameString || !Op->Common.Parent)
       {
           return_VOID;
       }
   
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
           "PATH OPTIMIZE: Line %5d ParentOp [%12.12s] ThisOp [%12.12s] ",
           Op->Asl.LogicalLineNumber,
           AcpiPsGetOpcodeName (Op->Common.Parent->Common.AmlOpcode),
           AcpiPsGetOpcodeName (Op->Common.AmlOpcode)));
   
       if (!(Flags & (AML_NAMED | AML_CREATE)))
       {
           if (Op->Asl.CompileFlags & OP_IS_NAME_DECLARATION)
           {
               /* We don't want to fuss with actual name declaration nodes here */
   
               ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
                   "******* NAME DECLARATION\n"));
               return_VOID;
           }
       }
   
       /*
        * The original path must be longer than one NameSeg (4 chars) for there
        * to be any possibility that it can be optimized to a shorter string
        */
       AmlNameStringLength = strlen (AmlNameString);
       if (AmlNameStringLength <= ACPI_NAMESEG_SIZE)
       {
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
               "NAMESEG %4.4s\n", AmlNameString));
           return_VOID;
       }
   
       /*
        * We need to obtain the node that represents the current scope -- where
        * we are right now in the namespace. We will compare this path
        * against the Namepath, looking for commonality.
        */
       CurrentNode = AcpiGbl_RootNode;
       if (WalkState->ScopeInfo)
       {
           CurrentNode = WalkState->ScopeInfo->Scope.Node;
       }
   
       if (Flags & (AML_NAMED | AML_CREATE))
       {
           /* This is the declaration of a new name */
   
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "NAME\n"));
   
           /*
            * The node of interest is the parent of this node (the containing
            * scope). The actual namespace node may be up more than one level
            * of parse op or it may not exist at all (if we traverse back
            * up to the root.)
            */
           NextOp = Op->Asl.Parent;
           while (NextOp && (!NextOp->Asl.Node))
           {
               NextOp = NextOp->Asl.Parent;
           }
   
           if (NextOp && NextOp->Asl.Node)
           {
               CurrentNode = NextOp->Asl.Node;
           }
           else
           {
               CurrentNode = AcpiGbl_RootNode;
           }
       }
       else
       {
           /* This is a reference to an existing named object */
   
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "REFERENCE\n"));
       }
   
       /*
        * Obtain the full paths to the two nodes that we are interested in
        * (Target and current namespace location) in external
        * format -- something we can easily manipulate
        */
       TargetPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER;
       Status = AcpiNsHandleToPathname (TargetNode, &TargetPath, FALSE);
       if (ACPI_FAILURE (Status))
       {
           AslCoreSubsystemError (Op, Status, "Getting Target NamePath",
               ASL_NO_ABORT);
           return_VOID;
       }
   
       TargetPath.Length--;    /* Subtract one for null terminator */
   
       /* CurrentPath is the path to this scope (where we are in the namespace) */
   
       CurrentPath.Length = ACPI_ALLOCATE_LOCAL_BUFFER;
       Status = AcpiNsHandleToPathname (CurrentNode, &CurrentPath, FALSE);
       if (ACPI_FAILURE (Status))
       {
           AslCoreSubsystemError (Op, Status, "Getting Current NamePath",
               ASL_NO_ABORT);
           return_VOID;
       }
   
       CurrentPath.Length--;   /* Subtract one for null terminator */
   
       /* Debug output only */
   
       Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, AmlNameString,
           NULL, &ExternalNameString);
       if (ACPI_FAILURE (Status))
       {
           AslCoreSubsystemError (Op, Status, "Externalizing NamePath",
               ASL_NO_ABORT);
           return_VOID;
       }
   
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
           "CURRENT SCOPE: (%2u) %-37s FULL PATH TO NAME: (%2u) %-32s ACTUAL AML:%-32s\n",
           (UINT32) CurrentPath.Length, (char *) CurrentPath.Pointer,
           (UINT32) TargetPath.Length, (char *) TargetPath.Pointer,
           ExternalNameString));
   
       ACPI_FREE (ExternalNameString);
   
       /*
        * Attempt an optimization depending on the type of namepath
        */
       if (Flags & (AML_NAMED | AML_CREATE))
       {
           /*
            * This is a named opcode and the namepath is a name declaration, not
            * a reference.
            */
           Status = OptOptimizeNameDeclaration (Op, WalkState, CurrentNode,
               TargetNode, AmlNameString, &NewPath);
           if (ACPI_FAILURE (Status))
           {
               /*
                * 2) now attempt to
                *    optimize the namestring with carats (up-arrow)
                */
               Status = OptBuildShortestPath (Op, WalkState, CurrentNode,
                   TargetNode, &CurrentPath, &TargetPath,
                   AmlNameStringLength, 1, &NewPath);
           }
       }
       else
       {
           /*
            * This is a reference to an existing named object
            *
            * 1) Check if search-to-root can be utilized using the last
            *    NameSeg of the NamePath
            */
           Status = OptSearchToRoot (Op, WalkState, CurrentNode,
               TargetNode, &TargetPath, &NewPath);
           if (ACPI_FAILURE (Status))
           {
               /*
                * 2) Search-to-root could not be used, now attempt to
                *    optimize the namestring with carats (up-arrow)
                */
               Status = OptBuildShortestPath (Op, WalkState, CurrentNode,
                   TargetNode, &CurrentPath, &TargetPath,
                   AmlNameStringLength, 0, &NewPath);
           }
       }
   
       /*
        * Success from above indicates that the NamePath was successfully
        * optimized. We need to update the parse op with the new name
        */
       if (ACPI_SUCCESS (Status))
       {
           HowMuchShorter = (AmlNameStringLength - strlen (NewPath));
           OptTotal += HowMuchShorter;
   
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS,
               " REDUCED BY %2u (TOTAL SAVED %2u)",
               (UINT32) HowMuchShorter, OptTotal));
   
           if (Flags & AML_NAMED)
           {
               if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
               {
                   /*
                    * ALIAS is the only oddball opcode, the name declaration
                    * (alias name) is the second operand
                    */
                   Op->Asl.Child->Asl.Next->Asl.Value.String = NewPath;
                   Op->Asl.Child->Asl.Next->Asl.AmlLength = strlen (NewPath);
               }
               else
               {
                   Op->Asl.Child->Asl.Value.String = NewPath;
                   Op->Asl.Child->Asl.AmlLength = strlen (NewPath);
               }
           }
           else if (Flags & AML_CREATE)
           {
               /* Name must appear as the last parameter */
   
               NextOp = Op->Asl.Child;
               while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
               {
                   NextOp = NextOp->Asl.Next;
               }
               /* Update the parse node with the new NamePath */
   
               NextOp->Asl.Value.String = NewPath;
               NextOp->Asl.AmlLength = strlen (NewPath);
           }
           else
           {
               /* Update the parse node with the new NamePath */
   
               Op->Asl.Value.String = NewPath;
               Op->Asl.AmlLength = strlen (NewPath);
           }
       }
       else
       {
           ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, " ALREADY OPTIMAL"));
       }
   
       /* Cleanup path buffers */
   
       ACPI_FREE (TargetPath.Pointer);
       ACPI_FREE (CurrentPath.Pointer);
   
       ACPI_DEBUG_PRINT_RAW ((ACPI_DB_OPTIMIZATIONS, "\n"));
       return_VOID;
   }

Cache object: 6bf503e7a7a52d43835c19a98b417ad4