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

     /******************************************************************************
      *
      * Module Name: aslfold - Constant folding
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
      * 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/amlcode.h>
   
   #include <contrib/dev/acpica/include/acdispat.h>
   #include <contrib/dev/acpica/include/acparser.h>
   
   #define _COMPONENT          ACPI_COMPILER
           ACPI_MODULE_NAME    ("aslfold")
   
   /* Local prototypes */
   
   static ACPI_STATUS
   OpcAmlEvaluationWalk1 (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context);
   
   static ACPI_STATUS
   OpcAmlEvaluationWalk2 (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context);
   
   static ACPI_STATUS
   OpcAmlCheckForConstant (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context);
   
   static void
   OpcUpdateIntegerNode (
       ACPI_PARSE_OBJECT       *Op,
       UINT64                  Value);
   
   static ACPI_STATUS
   TrTransformToStoreOp (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState);
   
   static ACPI_STATUS
   TrSimpleConstantReduction (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState);
   
   static void
   TrInstallReducedConstant (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_OPERAND_OBJECT     *ObjDesc);
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OpcAmlConstantWalk
    *
    * PARAMETERS:  ASL_WALK_CALLBACK
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Reduce an Op and its subtree to a constant if possible.
    *              Called during ascent of the parse tree.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   OpcAmlConstantWalk (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context)
   {
       ACPI_WALK_STATE         *WalkState;
       ACPI_STATUS             Status = AE_OK;
   
   
       if (Op->Asl.CompileFlags == 0)
       {
           return (AE_OK);
       }
   
       /*
        * Only interested in subtrees that could possibly contain
        * expressions that can be evaluated at this time
        */
       if ((!(Op->Asl.CompileFlags & OP_COMPILE_TIME_CONST)) ||
             (Op->Asl.CompileFlags & OP_IS_TARGET))
       {
           return (AE_OK);
       }
   
       /* Create a new walk state */
   
       WalkState = AcpiDsCreateWalkState (0, NULL, NULL, NULL);
       if (!WalkState)
       {
           return (AE_NO_MEMORY);
       }
   
       WalkState->NextOp = NULL;
       WalkState->Params = NULL;
   
       /*
        * Examine the entire subtree -- all nodes must be constants
        * or type 3/4/5 opcodes
        */
       Status = TrWalkParseTree (Op, ASL_WALK_VISIT_DOWNWARD,
           OpcAmlCheckForConstant, NULL, WalkState);
   
       /*
        * Did we find an entire subtree that contains all constants
        * and type 3/4/5 opcodes?
        */
       switch (Status)
       {
       case AE_OK:
   
           /* Simple case, like Add(3,4) -> 7 */
   
           Status = TrSimpleConstantReduction (Op, WalkState);
           break;
   
       case AE_CTRL_RETURN_VALUE:
   
           /* More complex case, like Add(3,4,Local0) -> Store(7,Local0) */
   
           Status = TrTransformToStoreOp (Op, WalkState);
           break;
   
       case AE_TYPE:
   
           AcpiDsDeleteWalkState (WalkState);
           return (AE_OK);
   
       default:
           AcpiDsDeleteWalkState (WalkState);
           break;
       }
   
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT, "Cannot resolve, %s\n",
               AcpiFormatException (Status));
   
           /* We could not resolve the subtree for some reason */
   
           AslError (ASL_ERROR, ASL_MSG_CONSTANT_EVALUATION, Op,
               (char *) AcpiFormatException (Status));
   
           /* Set the subtree value to ZERO anyway. Eliminates further errors */
   
           OpcUpdateIntegerNode (Op, 0);
       }
   
       return (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OpcAmlCheckForConstant
    *
    * PARAMETERS:  ASL_WALK_CALLBACK
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Check one Op for a reducible type 3/4/5 AML opcode.
    *              This is performed via an upward walk of the parse subtree.
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OpcAmlCheckForConstant (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context)
   {
       ACPI_WALK_STATE         *WalkState = Context;
       ACPI_STATUS             Status = AE_OK;
       ACPI_PARSE_OBJECT       *NextOp;
       const ACPI_OPCODE_INFO  *OpInfo;
   
   
       WalkState->Op = Op;
       WalkState->Opcode = Op->Common.AmlOpcode;
       WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
   
       DbgPrint (ASL_PARSE_OUTPUT, "[%.4d] Opcode: %12.12s ",
           Op->Asl.LogicalLineNumber, Op->Asl.ParseOpName);
   
       /*
        * These opcodes do not appear in the OpcodeInfo table, but
        * they represent constants, so abort the constant walk now.
        */
       if ((WalkState->Opcode == AML_RAW_DATA_BYTE) ||
           (WalkState->Opcode == AML_RAW_DATA_WORD) ||
           (WalkState->Opcode == AML_RAW_DATA_DWORD) ||
           (WalkState->Opcode == AML_RAW_DATA_QWORD))
       {
           DbgPrint (ASL_PARSE_OUTPUT, "RAW DATA");
           Status = AE_TYPE;
           goto CleanupAndExit;
       }
   
       /*
        * Search upwards for a possible Name() operator. This is done
        * because a type 3/4/5 opcode within a Name() expression
        * MUST be reduced to a simple constant.
        */
       NextOp = Op->Asl.Parent;
       while (NextOp)
       {
           /* Finished if we find a Name() opcode */
   
           if (NextOp->Asl.AmlOpcode == AML_NAME_OP)
           {
               break;
           }
   
           /*
            * Any "deferred" opcodes contain one or more TermArg parameters,
            * and thus are not required to be folded to constants at compile
            * time. This affects things like Buffer() and Package() objects.
            * We just ignore them here. However, any sub-expressions can and
            * will still be typechecked. Note: These are called the
            * "deferred" opcodes in the AML interpreter.
            */
           OpInfo = AcpiPsGetOpcodeInfo (NextOp->Common.AmlOpcode);
           if (OpInfo->Flags & AML_DEFER)
           {
               NextOp = NULL;
               break;
           }
   
           NextOp = NextOp->Asl.Parent;
       }
   
       /* Type 3/4/5 opcodes have the AML_CONSTANT flag set */
   
       if (!(WalkState->OpInfo->Flags & AML_CONSTANT))
       {
           /*
            * From the ACPI specification:
            *
            * "The Type 3/4/5 opcodes return a value and can be used in an
            * expression that evaluates to a constant. These opcodes may be
            * evaluated at ASL compile-time. To ensure that these opcodes
            * will evaluate to a constant, the following rules apply: The
            * term cannot have a destination (target) operand, and must have
            * either a Type3Opcode, Type4Opcode, Type5Opcode, ConstExprTerm,
            * Integer, BufferTerm, Package, or String for all arguments."
            */
   
           /*
            * The value (second) operand for the Name() operator MUST
            * reduce to a single constant, as per the ACPI specification
            * (the operand is a DataObject). This also implies that there
            * can be no target operand. Name() is the only ASL operator
            * with a "DataObject" as an operand and is thus special-
            * cased here.
            */
           if (NextOp) /* Inspect a Name() operator */
           {
               /* Error if there is a target operand */
   
               if (Op->Asl.CompileFlags & OP_IS_TARGET)
               {
                   AslError (ASL_ERROR, ASL_MSG_INVALID_TARGET, Op, NULL);
                   Status = AE_TYPE;
               }
   
               /* Error if expression cannot be reduced (folded) */
   
               if (!(NextOp->Asl.CompileFlags & OP_COULD_NOT_REDUCE))
               {
                   /* Ensure only one error message per statement */
   
                   NextOp->Asl.CompileFlags |= OP_COULD_NOT_REDUCE;
                   DbgPrint (ASL_PARSE_OUTPUT,
                       "**** Could not reduce operands for NAME opcode ****\n");
   
                   AslError (ASL_ERROR, ASL_MSG_CONSTANT_REQUIRED, Op,
                       "Constant is required for Name operator");
                   Status = AE_TYPE;
               }
           }
   
           if (ACPI_FAILURE (Status))
           {
               goto CleanupAndExit;
           }
   
           /* This is not a 3/4/5 opcode, but maybe can convert to STORE */
   
           if (Op->Asl.CompileFlags & OP_IS_TARGET)
           {
               DbgPrint (ASL_PARSE_OUTPUT,
                   "**** Valid Target, transform to Store or CopyObject ****\n");
               return (AE_CTRL_RETURN_VALUE);
           }
   
           /* Expression cannot be reduced */
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "**** Not a Type 3/4/5 opcode or cannot reduce/fold (%s) ****\n",
                Op->Asl.ParseOpName);
   
           Status = AE_TYPE;
           goto CleanupAndExit;
       }
   
       /*
        * TBD: Ignore buffer constants for now. The problem is that these
        * constants have been transformed into RAW_DATA at this point, from
        * the parse tree transform process which currently happens before
        * the constant folding process. We may need to defer this transform
        * for buffer until after the constant folding.
        */
       if (WalkState->Opcode == AML_BUFFER_OP)
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "\nBuffer constant reduction is currently not supported\n");
   
           if (NextOp) /* Found a Name() operator, error */
           {
               AslError (ASL_ERROR, ASL_MSG_UNSUPPORTED, Op,
                   "Buffer expression cannot be reduced");
           }
   
           Status = AE_TYPE;
           goto CleanupAndExit;
       }
   
       /* Debug output */
   
       DbgPrint (ASL_PARSE_OUTPUT, "TYPE_345");
   
       if (Op->Asl.CompileFlags & OP_IS_TARGET)
       {
           if (Op->Asl.ParseOpcode == PARSEOP_ZERO)
           {
               DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " NULL TARGET");
           }
           else
           {
               DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " VALID TARGET");
           }
       }
   
       if (Op->Asl.CompileFlags & OP_IS_TERM_ARG)
       {
           DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " TERMARG");
       }
   
   CleanupAndExit:
   
       /* Dump the node compile flags also */
   
       TrPrintOpFlags (Op->Asl.CompileFlags, ASL_PARSE_OUTPUT);
       DbgPrint (ASL_PARSE_OUTPUT, "\n");
       return (Status);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    TrSimpleConstantReduction
    *
    * PARAMETERS:  Op                  - Parent operator to be transformed
    *              WalkState           - Current walk state
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Reduce an entire AML operation to a single constant. The
    *              operation must not have a target operand.
    *
    *              Add (32,64) --> 96
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   TrSimpleConstantReduction (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState)
   {
       ACPI_PARSE_OBJECT       *RootOp;
       ACPI_PARSE_OBJECT       *OriginalParentOp;
       ACPI_OPERAND_OBJECT     *ObjDesc;
       ACPI_STATUS             Status;
   
   
       DbgPrint (ASL_PARSE_OUTPUT,
           "Simple subtree constant reduction, operator to constant\n");
   
       /* Allocate a new temporary root for this subtree */
   
       RootOp = TrAllocateOp (PARSEOP_INTEGER);
       if (!RootOp)
       {
           return (AE_NO_MEMORY);
       }
   
       RootOp->Common.AmlOpcode = AML_INT_EVAL_SUBTREE_OP;
   
       OriginalParentOp = Op->Common.Parent;
       Op->Common.Parent = RootOp;
   
       /* Hand off the subtree to the AML interpreter */
   
       WalkState->CallerReturnDesc = &ObjDesc;
   
       Status = TrWalkParseTree (Op, ASL_WALK_VISIT_TWICE,
           OpcAmlEvaluationWalk1, OpcAmlEvaluationWalk2, WalkState);
   
       /* Restore original parse tree */
   
       Op->Common.Parent = OriginalParentOp;
   
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant Subtree evaluation(1), %s\n",
               AcpiFormatException (Status));
           return (Status);
       }
   
       /* Get the final result */
   
       Status = AcpiDsResultPop (&ObjDesc, WalkState);
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant Subtree evaluation(2), %s\n",
               AcpiFormatException (Status));
           return (Status);
       }
   
       /* Disconnect any existing children, install new constant */
   
       Op->Asl.Child = NULL;
       TrInstallReducedConstant (Op, ObjDesc);
   
       UtSetParseOpName (Op);
       return (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    TrTransformToStoreOp
    *
    * PARAMETERS:  Op                  - Parent operator to be transformed
    *              WalkState           - Current walk state
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Transforms a single AML operation with a constant and target
    *              to a simple store operation:
    *
    *              Add (32,64,DATA) --> Store (96,DATA)
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   TrTransformToStoreOp (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_WALK_STATE         *WalkState)
   {
       ACPI_PARSE_OBJECT       *OriginalTarget;
       ACPI_PARSE_OBJECT       *NewTarget;
       ACPI_PARSE_OBJECT       *Child1;
       ACPI_PARSE_OBJECT       *Child2;
       ACPI_OPERAND_OBJECT     *ObjDesc;
       ACPI_PARSE_OBJECT       *NewParent;
       ACPI_PARSE_OBJECT       *OriginalParent;
       ACPI_STATUS             Status;
       UINT16                  NewParseOpcode;
       UINT16                  NewAmlOpcode;
   
   
       /* Extract the operands */
   
       Child1 = Op->Asl.Child;
       Child2 = Child1->Asl.Next;
   
       /*
        * Special case for DIVIDE -- it has two targets. The first
        * is for the remainder and if present, we will not attempt
        * to reduce the expression.
        */
       if (Op->Asl.ParseOpcode == PARSEOP_DIVIDE)
       {
           Child2 = Child2->Asl.Next;
           if (Child2->Asl.ParseOpcode != PARSEOP_ZERO)
           {
               DbgPrint (ASL_PARSE_OUTPUT,
                   "Cannot reduce DIVIDE - has two targets\n\n");
               return (AE_OK);
           }
       }
   
       switch (Op->Asl.ParseOpcode)
       {
       /*
        * Folding of the explicit conversion opcodes must use CopyObject
        * instead of Store. This can change the object type of the target
        * operand, as per the ACPI specification:
        *
        * "If the ASL operator is one of the explicit conversion operators
        * (ToString, ToInteger, etc., and the CopyObject operator), no
        * [implicit] conversion is performed. (In other words, the result
        * object is stored directly to the target and completely overwrites
        * any existing object already stored at the target)"
        */
       case PARSEOP_TOINTEGER:
       case PARSEOP_TOSTRING:
       case PARSEOP_TOBUFFER:
       case PARSEOP_TODECIMALSTRING:
       case PARSEOP_TOHEXSTRING:
       case PARSEOP_TOBCD:
       case PARSEOP_FROMBCD:
   
           NewParseOpcode = PARSEOP_COPYOBJECT;
           NewAmlOpcode = AML_COPY_OBJECT_OP;
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "Reduction/Transform to CopyObjectOp: CopyObject(%s, %s)\n",
               Child1->Asl.ParseOpName, Child2->Asl.ParseOpName);
           break;
   
       default:
   
           NewParseOpcode = PARSEOP_STORE;
           NewAmlOpcode = AML_STORE_OP;
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "Reduction/Transform to StoreOp: Store(%s, %s)\n",
               Child1->Asl.ParseOpName, Child2->Asl.ParseOpName);
           break;
       }
   
       /*
        * Create a NULL (zero) target so that we can use the
        * interpreter to evaluate the expression.
        */
       NewTarget = TrCreateNullTargetOp ();
       NewTarget->Common.AmlOpcode = AML_INT_NAMEPATH_OP;
   
       /* Handle one-operand cases (NOT, TOBCD, etc.) */
   
       if (!Child2->Asl.Next)
       {
           Child2 = Child1;
       }
   
       /* Link in new NULL target as the last operand */
   
       OriginalTarget = Child2->Asl.Next;
       Child2->Asl.Next = NewTarget;
       NewTarget->Asl.Parent = OriginalTarget->Asl.Parent;
   
       NewParent = TrAllocateOp (PARSEOP_INTEGER);
       NewParent->Common.AmlOpcode = AML_INT_EVAL_SUBTREE_OP;
   
       OriginalParent = Op->Common.Parent;
       Op->Common.Parent = NewParent;
   
       /* Hand off the subtree to the AML interpreter */
   
       WalkState->CallerReturnDesc = &ObjDesc;
   
       Status = TrWalkParseTree (Op, ASL_WALK_VISIT_TWICE,
           OpcAmlEvaluationWalk1, OpcAmlEvaluationWalk2, WalkState);
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant Subtree evaluation(3), %s\n",
               AcpiFormatException (Status));
           goto EvalError;
       }
   
       /* Get the final result */
   
       Status = AcpiDsResultPop (&ObjDesc, WalkState);
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant Subtree evaluation(4), %s\n",
               AcpiFormatException (Status));
           goto EvalError;
       }
   
       /* Truncate any subtree expressions, they have been evaluated */
   
       Child1->Asl.Child = NULL;
   
       /* Folded constant is in ObjDesc, store into Child1 */
   
       TrInstallReducedConstant (Child1, ObjDesc);
   
       /* Convert operator to STORE or COPYOBJECT */
   
       Op->Asl.ParseOpcode = NewParseOpcode;
       Op->Asl.AmlOpcode = NewAmlOpcode;
       UtSetParseOpName (Op);
       Op->Common.Parent = OriginalParent;
   
       /* First child is the folded constant */
   
       /* Second child will be the target */
   
       Child1->Asl.Next = OriginalTarget;
       return (AE_OK);
   
   
   EvalError:
   
       /* Restore original links */
   
       Op->Common.Parent = OriginalParent;
       Child2->Asl.Next = OriginalTarget;
       return (Status);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    TrInstallReducedConstant
    *
    * PARAMETERS:  Op                  - Parent operator to be transformed
    *              ObjDesc             - Reduced constant to be installed
    *
    * RETURN:      None
    *
    * DESCRIPTION: Transform the original operator to a simple constant.
    *              Handles Integers, Strings, and Buffers.
    *
    ******************************************************************************/
   
   static void
   TrInstallReducedConstant (
       ACPI_PARSE_OBJECT       *Op,
       ACPI_OPERAND_OBJECT     *ObjDesc)
   {
       ACPI_PARSE_OBJECT       *LengthOp;
       ACPI_PARSE_OBJECT       *DataOp;
   
   
       AslGbl_TotalFolds++;
       AslError (ASL_OPTIMIZATION, ASL_MSG_CONSTANT_FOLDED, Op,
           Op->Asl.ParseOpName);
   
       /*
        * Because we know we executed type 3/4/5 opcodes above, we know that
        * the result must be either an Integer, String, or Buffer.
        */
       switch (ObjDesc->Common.Type)
       {
       case ACPI_TYPE_INTEGER:
   
           OpcUpdateIntegerNode (Op, ObjDesc->Integer.Value);
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant expression reduced to (%s) %8.8X%8.8X\n\n",
               Op->Asl.ParseOpName,
               ACPI_FORMAT_UINT64 (Op->Common.Value.Integer));
           break;
   
       case ACPI_TYPE_STRING:
   
           Op->Asl.ParseOpcode = PARSEOP_STRING_LITERAL;
           Op->Common.AmlOpcode = AML_STRING_OP;
           Op->Asl.AmlLength = strlen (ObjDesc->String.Pointer) + 1;
           Op->Common.Value.String = ObjDesc->String.Pointer;
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant expression reduced to (STRING) %s\n\n",
               Op->Common.Value.String);
           break;
   
       case ACPI_TYPE_BUFFER:
           /*
            * Create a new parse subtree of the form:
            *
            * BUFFER (Buffer AML opcode)
            *    INTEGER (Buffer length in bytes)
            *    RAW_DATA (Buffer byte data)
            */
           Op->Asl.ParseOpcode = PARSEOP_BUFFER;
           Op->Common.AmlOpcode = AML_BUFFER_OP;
           Op->Asl.CompileFlags = OP_AML_PACKAGE;
           UtSetParseOpName (Op);
   
           /* Child node is the buffer length */
   
           LengthOp = TrAllocateOp (PARSEOP_INTEGER);
   
           LengthOp->Asl.AmlOpcode = AML_DWORD_OP;
           LengthOp->Asl.Value.Integer = ObjDesc->Buffer.Length;
           LengthOp->Asl.Parent = Op;
           (void) OpcSetOptimalIntegerSize (LengthOp);
   
           Op->Asl.Child = LengthOp;
   
           /* Next child is the raw buffer data */
   
           DataOp = TrAllocateOp (PARSEOP_RAW_DATA);
           DataOp->Asl.AmlOpcode = AML_RAW_DATA_BUFFER;
           DataOp->Asl.AmlLength = ObjDesc->Buffer.Length;
           DataOp->Asl.Value.String = (char *) ObjDesc->Buffer.Pointer;
           DataOp->Asl.Parent = Op;
   
           LengthOp->Asl.Next = DataOp;
   
           DbgPrint (ASL_PARSE_OUTPUT,
               "Constant expression reduced to (BUFFER) length %X\n\n",
               ObjDesc->Buffer.Length);
           break;
   
       default:
           break;
       }
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OpcUpdateIntegerNode
    *
    * PARAMETERS:  Op                  - Current parse object
    *              Value               - Value for the integer op
    *
    * RETURN:      None
    *
    * DESCRIPTION: Update node to the correct Integer type and value
    *
    ******************************************************************************/
   
   static void
   OpcUpdateIntegerNode (
       ACPI_PARSE_OBJECT       *Op,
       UINT64                  Value)
   {
   
       Op->Common.Value.Integer = Value;
   
       /*
        * The AmlLength is used by the parser to indicate a constant,
        * (if non-zero). Length is either (1/2/4/8)
        */
       switch (Op->Asl.AmlLength)
       {
       case 1:
   
           TrSetOpIntegerValue (PARSEOP_BYTECONST, Op);
           Op->Asl.AmlOpcode = AML_RAW_DATA_BYTE;
           break;
   
       case 2:
   
           TrSetOpIntegerValue (PARSEOP_WORDCONST, Op);
           Op->Asl.AmlOpcode = AML_RAW_DATA_WORD;
           break;
   
       case 4:
   
           TrSetOpIntegerValue (PARSEOP_DWORDCONST, Op);
           Op->Asl.AmlOpcode = AML_RAW_DATA_DWORD;
           break;
   
       case 8:
   
           TrSetOpIntegerValue (PARSEOP_QWORDCONST, Op);
           Op->Asl.AmlOpcode = AML_RAW_DATA_QWORD;
           break;
   
       case 0:
       default:
   
           OpcSetOptimalIntegerSize (Op);
           TrSetOpIntegerValue (PARSEOP_INTEGER, Op);
           break;
       }
   
       Op->Asl.AmlLength = 0;
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OpcAmlEvaluationWalk1
    *
    * PARAMETERS:  ASL_WALK_CALLBACK
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Descending callback for AML execution of constant subtrees
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OpcAmlEvaluationWalk1 (
       ACPI_PARSE_OBJECT       *Op,
       UINT32                  Level,
       void                    *Context)
   {
       ACPI_WALK_STATE         *WalkState = Context;
       ACPI_STATUS             Status;
       ACPI_PARSE_OBJECT       *OutOp;
   
   
       WalkState->Op = Op;
       WalkState->Opcode = Op->Common.AmlOpcode;
       WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
   
       /* Copy child pointer to Arg for compatibility with Interpreter */
   
       if (Op->Asl.Child)
       {
           Op->Common.Value.Arg = Op->Asl.Child;
       }
   
       /* Call AML dispatcher */
   
       Status = AcpiDsExecBeginOp (WalkState, &OutOp);
       if (ACPI_FAILURE (Status))
       {
           DbgPrint (ASL_PARSE_OUTPUT,
               "%s Constant interpretation failed (1) - %s\n",
               Op->Asl.ParseOpName, AcpiFormatException (Status));
       }
   
       return (Status);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    OpcAmlEvaluationWalk2
    *
    * PARAMETERS:  ASL_WALK_CALLBACK
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Ascending callback for AML execution of constant subtrees
    *
    ******************************************************************************/
   
   static ACPI_STATUS
   OpcAmlEvaluationWalk2 (
      ACPI_PARSE_OBJECT       *Op,
      UINT32                  Level,
      void                    *Context)
  {
      ACPI_WALK_STATE         *WalkState = Context;
      ACPI_STATUS             Status;
  
  
      WalkState->Op = Op;
      WalkState->Opcode = Op->Common.AmlOpcode;
      WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
  
      /* Copy child pointer to Arg for compatibility with Interpreter */
  
      if (Op->Asl.Child)
      {
          Op->Common.Value.Arg = Op->Asl.Child;
      }
  
      /* Call AML dispatcher */
  
      Status = AcpiDsExecEndOp (WalkState);
      if (ACPI_FAILURE (Status))
      {
          DbgPrint (ASL_PARSE_OUTPUT,
              "%s: Constant interpretation failed (2) - %s\n",
              Op->Asl.ParseOpName, AcpiFormatException (Status));
      }
  
      return (Status);
  }

Cache object: ae91b04c0ca72e067480edafa47796e7