[WWW PATCH] Add s390 back-end 4.0 changes

[Ulrich Weigand]

Hello,

this patch adds the s390 back-end changes to the 4.0 web page.
OK?

Bye,
Ulrich


Index: htdocs/gcc-4.0/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.0/changes.html,v
retrieving revision 1.22
diff -c -p -r1.22 changes.html
*** htdocs/gcc-4.0/changes.html	3 Dec 2004 05:22:14 -0000	1.22
--- htdocs/gcc-4.0/changes.html	17 Dec 2004 15:03:15 -0000
*************** class N::A {
*** 363,368 ****
--- 363,413 ----
          <code>-mfix-vr4120</code> respectively.</li>
    </ul>
  
+ <h3>S/390 and zSeries</h3>
+   <ul>
+     <li>New command line options help to generate code intended to
+ 	run in an environment where stack space is restricted,
+ 	e.g. Linux kernel code:
+ 	<ul>
+ 	  <li><code>-mwarn-framesize</code> and
+ 	      <code>-mwarn-dynamicstack</code> trigger compile-time
+ 	      warnings for single functions that require large or
+ 	      dynamic stack frames.</li>
+ 	  <li><code>-mstack-size</code> and <code>-mstack-guard</code>
+ 	      generate code that checks for stack overflow at run time.</li>
+ 	  <li><code>-mpacked-stack</code> generates code that reduces
+ 	      the stack frame size of many functions by reusing unneeded
+ 	      parts of the stack bias area.</li>
+ 	</ul></li>
+     <li>The <code>-msoft-float</code> option now ensures that generated
+ 	code never accesses floating point registers.</li>
+     <li>The <code>s390x-ibm-tpf</code> target now fully supports C++,
+ 	including exceptions and threads.</li>
+     <li>Various changes to improve performance of the generated code
+ 	have been implemented, including:
+ 	<ul>
+ 	  <li>GCC now uses sibling calls where possible.</li>
+ 	  <li>Condition code handling has been optimized, allowing GCC
+ 	      to omit redundant comparisons in certain cases.</li>
+ 	  <li>The cost function guiding many optimizations has been
+ 	      refined to more accurately represent the z900 and z990
+ 	      processors.</li>
+ 	  <li>The <code>ADD LOGICAL WITH CARRY</code> and <code>SUBTRACT
+ 	      LOGICAL WITH BORROW</code> instructions are now used to
+ 	      avoid conditional branches in certain cases.</li>
+ 	  <li>The back end now uses the <code>LEGITIMIZE_RELOAD_ADDRESS</code>
+ 	      feature to optimize address arithmetic required to access large
+ 	      stack frames.</li>
+ 	  <li>GCC now makes more efficient use of memory-to-memory type
+ 	      instructions (<code>MVC</code>, <code>CLC</code>, ...).</li>
+ 	  <li>More precise tracking of special register use allows better
+ 	      instruction scheduling, in particular of the function 
+ 	      prologue and epilogue sequences.</li>
+ 	  <li>The Java front end now generates inline code to implement
+ 	      integer division, instead of calling library routines.</li>
+ 	</ul></li>
+   </ul>
+ 
  <h3>SPARC</h3>
    <ul>
      <li>The options <code>-mv8</code>, <code>-msparclite</code>,
-- 
  Dr. Ulrich Weigand
  Linux on zSeries Development
  Ulrich.Weigand@de.ibm.com