ECO NUMBER:	 CC01057
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                PRODUCT:	 DEC C for OpenVMS Alpha
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                UPDATED PRODUCT: DEC C for OpenVMS Alpha 5.7
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                APPRX BLCK SIZE: 32886
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          Cover Letter for DEC C V5.7 ECO Kit CC01057 for OpenVMS Alpha.

          ECO Kit CC01057 Description

          The DEC C V5.7 ECO 1 for OpenVMS Alpha Release Notes contain a
          complete explanation of this kit. Below is a brief description
          of the problems addressed by this kit:

          o  A developers command line option /switch=weak_volatile has
             been enabled to specify that code generated for volatile
             accesses to objects smaller than 32-bits should not use the
             load-locked/store-conditional instruction sequence. In rare
             kinds of code making use of direct memory-mapped I/O devices,
             the locked sequences can cause hangs.

          o  Intrinsic functions used in combination with 64-bit pointers
             could produce a number of spurious compiler diagnostics.

          o  The pow intrinsic erroneously produced a zero result for a
             negative base value.

          o  /preprocessor_only output stripped the leading L character
             from wide string literals.

          o  The expansion of the offsetof macro could trigger an asser-
             tion failure in the compiler under the /noopt qualifier.

          o  The compiler sometimes generated procedure prologues that
             violated the OpenVMS calling standard, leading to debugger
             complaints about corrupt stack, and possible real stack
             corruption in threaded code.

          o  The compiler generated incorrect code when casting a function
             pointer to a pointer to a procedure descriptor, which was
             then used to access a field in the procedure descriptor other
             than the code address.

          o  Negative literal values in a shareable image produced by
             the OpenVMS message compiler could lose sign extension when
             accessed from a C programs and cast to type int.




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          Installation Overview

          This ECO kit is installed using VMSINSTAL at the DCL prompt from
          the SYSTEM account as follows:

             @SYS$UPDATE:VMSINSTAL CC01057 [location of the saveset]

          The installation procedure processing is the same as for the
          original V5.7-004 kit, the difference being in the content of
          the executable images for the compiler and its message library.
          The saveset location can be a tape drive or a disk directory
          that contains the kit saveset. If the saveset is copied to disk,
          it must not be renamed.







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  Copyright (c) Compaq Computer Corporation 1998.  All Rights reserved.

  This software is proprietary to and embodies the confidential technology
  of Compaq Computer Corporation.  Possession, use, or copying of this
  software and media is authorized only pursuant to a valid written license
  from Compaq or an authorized sublicensor.

        This ECO has not been through an exhaustive field test process.
        Due to the experimental stage of this ECO/workaround, Compaq
        makes no representations regarding its use or performance.  The
        customer shall have the sole responsibility for adequate protection
        and back-up data used in conjunction with this ECO/workaround.