FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/components/utilities/utmath.c

     /*******************************************************************************
      *
      * Module Name: utmath - Integer math support routines
      *
      ******************************************************************************/
     
     /******************************************************************************
      *
      * 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/include/acpi.h>
   #include <contrib/dev/acpica/include/accommon.h>
   
   
   #define _COMPONENT          ACPI_UTILITIES
           ACPI_MODULE_NAME    ("utmath")
   
   /* Structures used only for 64-bit divide */
   
   typedef struct uint64_struct
   {
       UINT32                          Lo;
       UINT32                          Hi;
   
   } UINT64_STRUCT;
   
   typedef union uint64_overlay
   {
       UINT64                          Full;
       UINT64_STRUCT                   Part;
   
   } UINT64_OVERLAY;
   
   /*
    * Optional support for 64-bit double-precision integer multiply and shift.
    * This code is configurable and is implemented in order to support 32-bit
    * kernel environments where a 64-bit double-precision math library is not
    * available.
    */
   #ifndef ACPI_USE_NATIVE_MATH64
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortMultiply
    *
    * PARAMETERS:  Multiplicand        - 64-bit multiplicand
    *              Multiplier          - 32-bit multiplier
    *              OutProduct          - Pointer to where the product is returned
    *
    * DESCRIPTION: Perform a short multiply.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortMultiply (
       UINT64                  Multiplicand,
       UINT32                  Multiplier,
       UINT64                  *OutProduct)
   {
       UINT64_OVERLAY          MultiplicandOvl;
       UINT64_OVERLAY          Product;
       UINT32                  Carry32;
   
   
       ACPI_FUNCTION_TRACE (UtShortMultiply);
   
   
       MultiplicandOvl.Full = Multiplicand;
   
       /*
        * The Product is 64 bits, the carry is always 32 bits,
        * and is generated by the second multiply.
        */
       ACPI_MUL_64_BY_32 (0, MultiplicandOvl.Part.Hi, Multiplier,
           Product.Part.Hi, Carry32);
   
       ACPI_MUL_64_BY_32 (0, MultiplicandOvl.Part.Lo, Multiplier,
           Product.Part.Lo, Carry32);
   
       Product.Part.Hi += Carry32;
   
       /* Return only what was requested */
   
       if (OutProduct)
       {
           *OutProduct = Product.Full;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortShiftLeft
    *
    * PARAMETERS:  Operand             - 64-bit shift operand
    *              Count               - 32-bit shift count
    *              OutResult           - Pointer to where the result is returned
    *
    * DESCRIPTION: Perform a short left shift.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortShiftLeft (
       UINT64                  Operand,
       UINT32                  Count,
       UINT64                  *OutResult)
   {
       UINT64_OVERLAY          OperandOvl;
   
   
       ACPI_FUNCTION_TRACE (UtShortShiftLeft);
   
   
       OperandOvl.Full = Operand;
   
       if ((Count & 63) >= 32)
       {
           OperandOvl.Part.Hi = OperandOvl.Part.Lo;
           OperandOvl.Part.Lo = 0;
           Count = (Count & 63) - 32;
       }
       ACPI_SHIFT_LEFT_64_BY_32 (OperandOvl.Part.Hi,
           OperandOvl.Part.Lo, Count);
   
       /* Return only what was requested */
   
       if (OutResult)
       {
           *OutResult = OperandOvl.Full;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortShiftRight
    *
    * PARAMETERS:  Operand             - 64-bit shift operand
    *              Count               - 32-bit shift count
    *              OutResult           - Pointer to where the result is returned
    *
    * DESCRIPTION: Perform a short right shift.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortShiftRight (
       UINT64                  Operand,
       UINT32                  Count,
       UINT64                  *OutResult)
   {
       UINT64_OVERLAY          OperandOvl;
   
   
       ACPI_FUNCTION_TRACE (UtShortShiftRight);
   
   
       OperandOvl.Full = Operand;
   
       if ((Count & 63) >= 32)
       {
           OperandOvl.Part.Lo = OperandOvl.Part.Hi;
           OperandOvl.Part.Hi = 0;
           Count = (Count & 63) - 32;
       }
       ACPI_SHIFT_RIGHT_64_BY_32 (OperandOvl.Part.Hi,
           OperandOvl.Part.Lo, Count);
   
       /* Return only what was requested */
   
       if (OutResult)
       {
           *OutResult = OperandOvl.Full;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   #else
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortMultiply
    *
    * PARAMETERS:  See function headers above
    *
    * DESCRIPTION: Native version of the UtShortMultiply function.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortMultiply (
       UINT64                  Multiplicand,
       UINT32                  Multiplier,
       UINT64                  *OutProduct)
   {
   
       ACPI_FUNCTION_TRACE (UtShortMultiply);
   
   
       /* Return only what was requested */
   
       if (OutProduct)
       {
           *OutProduct = Multiplicand * Multiplier;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortShiftLeft
    *
    * PARAMETERS:  See function headers above
    *
    * DESCRIPTION: Native version of the UtShortShiftLeft function.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortShiftLeft (
       UINT64                  Operand,
       UINT32                  Count,
       UINT64                  *OutResult)
   {
   
       ACPI_FUNCTION_TRACE (UtShortShiftLeft);
   
   
       /* Return only what was requested */
   
       if (OutResult)
       {
           *OutResult = Operand << Count;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortShiftRight
    *
    * PARAMETERS:  See function headers above
    *
    * DESCRIPTION: Native version of the UtShortShiftRight function.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortShiftRight (
       UINT64                  Operand,
       UINT32                  Count,
       UINT64                  *OutResult)
   {
   
       ACPI_FUNCTION_TRACE (UtShortShiftRight);
   
   
       /* Return only what was requested */
   
       if (OutResult)
       {
           *OutResult = Operand >> Count;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   #endif
   
   /*
    * Optional support for 64-bit double-precision integer divide. This code
    * is configurable and is implemented in order to support 32-bit kernel
    * environments where a 64-bit double-precision math library is not available.
    *
    * Support for a more normal 64-bit divide/modulo (with check for a divide-
    * by-zero) appears after this optional section of code.
    */
   #ifndef ACPI_USE_NATIVE_DIVIDE
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortDivide
    *
    * PARAMETERS:  Dividend            - 64-bit dividend
    *              Divisor             - 32-bit divisor
    *              OutQuotient         - Pointer to where the quotient is returned
    *              OutRemainder        - Pointer to where the remainder is returned
    *
    * RETURN:      Status (Checks for divide-by-zero)
    *
    * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits)
    *              divide and modulo. The result is a 64-bit quotient and a
    *              32-bit remainder.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortDivide (
       UINT64                  Dividend,
       UINT32                  Divisor,
       UINT64                  *OutQuotient,
       UINT32                  *OutRemainder)
   {
       UINT64_OVERLAY          DividendOvl;
       UINT64_OVERLAY          Quotient;
       UINT32                  Remainder32;
   
   
       ACPI_FUNCTION_TRACE (UtShortDivide);
   
   
       /* Always check for a zero divisor */
   
       if (Divisor == 0)
       {
           ACPI_ERROR ((AE_INFO, "Divide by zero"));
           return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
       }
   
       DividendOvl.Full = Dividend;
   
       /*
        * The quotient is 64 bits, the remainder is always 32 bits,
        * and is generated by the second divide.
        */
       ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor,
           Quotient.Part.Hi, Remainder32);
   
       ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor,
           Quotient.Part.Lo, Remainder32);
   
       /* Return only what was requested */
   
       if (OutQuotient)
       {
           *OutQuotient = Quotient.Full;
       }
       if (OutRemainder)
       {
           *OutRemainder = Remainder32;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtDivide
    *
    * PARAMETERS:  InDividend          - Dividend
    *              InDivisor           - Divisor
    *              OutQuotient         - Pointer to where the quotient is returned
    *              OutRemainder        - Pointer to where the remainder is returned
    *
    * RETURN:      Status (Checks for divide-by-zero)
    *
    * DESCRIPTION: Perform a divide and modulo.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtDivide (
       UINT64                  InDividend,
       UINT64                  InDivisor,
       UINT64                  *OutQuotient,
       UINT64                  *OutRemainder)
   {
       UINT64_OVERLAY          Dividend;
       UINT64_OVERLAY          Divisor;
       UINT64_OVERLAY          Quotient;
       UINT64_OVERLAY          Remainder;
       UINT64_OVERLAY          NormalizedDividend;
       UINT64_OVERLAY          NormalizedDivisor;
       UINT32                  Partial1;
       UINT64_OVERLAY          Partial2;
       UINT64_OVERLAY          Partial3;
   
   
       ACPI_FUNCTION_TRACE (UtDivide);
   
   
       /* Always check for a zero divisor */
   
       if (InDivisor == 0)
       {
           ACPI_ERROR ((AE_INFO, "Divide by zero"));
           return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
       }
   
       Divisor.Full  = InDivisor;
       Dividend.Full = InDividend;
       if (Divisor.Part.Hi == 0)
       {
           /*
            * 1) Simplest case is where the divisor is 32 bits, we can
            * just do two divides
            */
           Remainder.Part.Hi = 0;
   
           /*
            * The quotient is 64 bits, the remainder is always 32 bits,
            * and is generated by the second divide.
            */
           ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo,
               Quotient.Part.Hi, Partial1);
   
           ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo,
               Quotient.Part.Lo, Remainder.Part.Lo);
       }
   
       else
       {
           /*
            * 2) The general case where the divisor is a full 64 bits
            * is more difficult
            */
           Quotient.Part.Hi   = 0;
           NormalizedDividend = Dividend;
           NormalizedDivisor  = Divisor;
   
           /* Normalize the operands (shift until the divisor is < 32 bits) */
   
           do
           {
               ACPI_SHIFT_RIGHT_64 (
                   NormalizedDivisor.Part.Hi, NormalizedDivisor.Part.Lo);
               ACPI_SHIFT_RIGHT_64 (
                   NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo);
   
           } while (NormalizedDivisor.Part.Hi != 0);
   
           /* Partial divide */
   
           ACPI_DIV_64_BY_32 (
               NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo,
               NormalizedDivisor.Part.Lo, Quotient.Part.Lo, Partial1);
   
           /*
            * The quotient is always 32 bits, and simply requires
            * adjustment. The 64-bit remainder must be generated.
            */
           Partial1 = Quotient.Part.Lo * Divisor.Part.Hi;
           Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo;
           Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1;
   
           Remainder.Part.Hi = Partial3.Part.Lo;
           Remainder.Part.Lo = Partial2.Part.Lo;
   
           if (Partial3.Part.Hi == 0)
           {
               if (Partial3.Part.Lo >= Dividend.Part.Hi)
               {
                   if (Partial3.Part.Lo == Dividend.Part.Hi)
                   {
                       if (Partial2.Part.Lo > Dividend.Part.Lo)
                       {
                           Quotient.Part.Lo--;
                           Remainder.Full -= Divisor.Full;
                       }
                   }
                   else
                   {
                       Quotient.Part.Lo--;
                       Remainder.Full -= Divisor.Full;
                   }
               }
   
               Remainder.Full = Remainder.Full - Dividend.Full;
               Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi);
               Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo);
   
               if (Remainder.Part.Lo)
               {
                   Remainder.Part.Hi--;
               }
           }
       }
   
       /* Return only what was requested */
   
       if (OutQuotient)
       {
           *OutQuotient = Quotient.Full;
       }
       if (OutRemainder)
       {
           *OutRemainder = Remainder.Full;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   #else
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiUtShortDivide, AcpiUtDivide
    *
    * PARAMETERS:  See function headers above
    *
    * DESCRIPTION: Native versions of the UtDivide functions. Use these if either
    *              1) The target is a 64-bit platform and therefore 64-bit
    *                 integer math is supported directly by the machine.
    *              2) The target is a 32-bit or 16-bit platform, and the
    *                 double-precision integer math library is available to
    *                 perform the divide.
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiUtShortDivide (
       UINT64                  InDividend,
       UINT32                  Divisor,
       UINT64                  *OutQuotient,
       UINT32                  *OutRemainder)
   {
   
       ACPI_FUNCTION_TRACE (UtShortDivide);
   
   
       /* Always check for a zero divisor */
   
       if (Divisor == 0)
       {
           ACPI_ERROR ((AE_INFO, "Divide by zero"));
           return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
       }
   
       /* Return only what was requested */
   
       if (OutQuotient)
       {
           *OutQuotient = InDividend / Divisor;
       }
       if (OutRemainder)
       {
           *OutRemainder = (UINT32) (InDividend % Divisor);
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   ACPI_STATUS
   AcpiUtDivide (
       UINT64                  InDividend,
       UINT64                  InDivisor,
       UINT64                  *OutQuotient,
       UINT64                  *OutRemainder)
   {
       ACPI_FUNCTION_TRACE (UtDivide);
   
   
       /* Always check for a zero divisor */
   
       if (InDivisor == 0)
       {
           ACPI_ERROR ((AE_INFO, "Divide by zero"));
           return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
       }
   
   
       /* Return only what was requested */
   
       if (OutQuotient)
       {
           *OutQuotient = InDividend / InDivisor;
       }
       if (OutRemainder)
       {
           *OutRemainder = InDividend % InDivisor;
       }
   
       return_ACPI_STATUS (AE_OK);
   }
   
   #endif

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