TECHNICAL INFORMATION DOCUMENT

TITLE:              PTF230 - Compiler : Optimizer and Code Generator
DOCUMENT ID:        TID300202
DOCUMENT REVISION:  A
DATE:               10APR95
ALERT STATUS:       Yellow
INFORMATION TYPE:   Symptom Solution
README FOR:         ptf230

PRODUCT and VERSION:
UnixWare 1.1

ABSTRACT:

This PTF fixes three problems with the code generator and the optimizer 
in the "Optimizing C Compilation System" package.


SYMPTOM

In some rare cases, the code generator or optimizer produce incorrect output.

SOLUTION

Apply the ptf230 file.

Installation Instructions:  

DATATYPE: datastream


1.  Download the ptf230 and ptf230.txt files to the /tmp directory   
    on your machine.

2.  Read the release notes contained in this file and follow the
    instuctions to add the packages to your system.

3.  Now become root, and add the package to your system using the following
    commands:

        $ su
        # pkgadd -d /tmp/ptf230

Solution Specifics

PTF230 OVERVIEW
---------------

Title
-----

PTF230 - Compiler Fixes: Optimizer and Code Generator

Version
-------
1.0

Date
----

04APR95

Information Type
----------------

Symptom Solution

Product And Version
-------------------

UnixWare 1.1.1 or 1.1.2 or 1.1.3 or 1.1.4

Symptom
--------

In some rare cases, the code generator or optimizer produce 
incorrect output.  See the General Description below for more details.


General Description.
-------------------

Problem 1:  There is a problem with the compilation of certain 
floating point expressions involving the ?: operator. The incorrectly 
compiled code gives the wrong answer in cases where the same constant 
appears in both the "true" and the "false" expression of the ?: operator.

Problem 2:  The optimizer clobbers the value in a register in some rare 
cases.  The result is unpredictable.

Problem 3:  The optimizer replaces zero with a another (unpredictable) value
in some rare cases. The result is unpredictable.


New Features.
------------

None.

Software Notes and Recommendations.
----------------------------------

This PTF requires that UnixWare 1.1.1, 1.1.2, 1.1.3, or 1.1.4 be installed,
as well as the "Optimizing C Compilation System" (ccs) package.  If you
install the ccs package after you install an Update, you *must* reinstall the
Update before installing this PTF.

If, after you install this PTF, you decide to install an Update, you must
remove this PTF, install the Update, and then reinstall this PTF.

Testing of the modified software contained in this package has been
conducted only to the extent necessary to confirm that it resolves the
problem(s) stated above ("Symptom").  Such testing consists of
recreating the problem conditions and verifying that the problem no 
longer occurs.  No other testing of this software has been done.

Hardware Notes and Recommendations.
----------------------------------

This PTF is targeted for the i386, i486 and Pentium CPU's.

Installation Instructions.
-------------------------

This PTF consists of 1 3.5 inch floppy.  Insert the floppy into the drive
and, while logged in as root, type

     pkgadd -d diskette1

and follow the instructions output by pkgadd.

Troubleshooting.
---------------

To verify whether this PTF works after installing it, compile and run the
following programs.

===============================================================================
/*
 * The printf should print "3 2", but without this PTF
 * it prints "3 -2147483648"
 */
main ()
{
         int i1; double d1;
         d1 = 0.0;
         i1 = ( d1 > 0) ? 2 + d1 : 3;
         printf("%d ",i1);
         d1 = 0.0;
         i1 = ( d1 > 0) ? 2 + d1 : 2;
         printf("%d\n",i1);
}
===============================================================================
/*
 * The printf in main should print "0 1", but without this PTF
 * it prints "0 0" when this code is optimized.
 */

#include <stdio.h>

int
ematch(register char *s, register char *p) {
     register int    scc = *s++;
     char            c;

     switch(c = *p++) {
     case '[':
          while( c = *p++ ) {
          }
     case 0:
          return (1);
     default:
          {
               char c1 = c & 0177;
               char c2 = (char)scc;

               c1 = (c1 >= 'a' && c1 <= 'z') ? c1 - 'a' + 'A' : c1;
               c2 = (c2 >= 'a' && c2 <= 'z') ? c2 - 'a' + 'A' : c2;

               if( c1 != c2 ) {
                    return( 0 );
               }
          }

     }
     return(ematch(s,p));
}
main() {
     printf("%d %d\n", ematch("b", "a"), ematch("a.c", "a.c"));
}
===============================================================================