Re: egcs 1.0.2 success and problem

[Jeffrey A Law <law at cygnus dot com>]

  In message <199804052121.AAA00146@hadar.wisdom.weizmann.ac.il>you write:
  > I successfully compiled egcs 1.0.2 on RedHat 5.0 (no surprise I'm sure)
  > I haven't included config.guess if you want it just ask.
  > 
  > I noticed an optimization problem with gcc 2.7.2 and it is still present
  > in egcs 1.0.2 (I specifically wanted to test this problem).  I have pared
  > down the sources a fair bit, if I need to do more I will try.
I believe if you try the current sources in the egcs CVS tree you'll find that
the second (and more important) loop in your testcase is optimized noticably
better now.


Here's what you were getting:

  > .L11:
  > 	movl 8(%ebp),%edx
  > 	movl (%edx),%edx
  > 	movl %edx,%eax
  > 	xorl %edx,%edx
  > 	movl %eax,-16(%ebp)
  > 	movl %edx,-12(%ebp)
  > 	movl 8(%ebp),%edx
  > 	movl 4(%edx),%esi
  > 	movl 12(%edx),%ebx
  > 	movl 12(%ebp),%eax
  > 	movl (%ebx,%esi,4),%ecx
  > 	mull %ecx
  > 	movl %eax,-8(%ebp)
  > 	movl %edx,-4(%ebp)
  > 	pushl -12(%ebp)
  > 	pushl -16(%ebp)
  > 	pushl -4(%ebp)
  > 	pushl -8(%ebp)
  > 	call __umoddi3
  > 	movl %eax,-16(%ebp)
  > 	movl %edx,-12(%ebp)
  > 	addl $16,%esp
  > 	movl -16(%ebp),%edx
  > 	movl 8(%ebp),%eax
  > 	incl %edi
  > 	movl %edx,(%ebx,%esi,4)
  > 	cmpl %edi,4(%eax)
  > 	ja .L11

Here's what I get with the current sources:

.L11:
        movl -4(%ebp),%ebx
        movl 12(%ebp),%eax
        movl (%ebx,%edi,4),%ecx
        mull %ecx
        movl 8(%ebp),%ecx
        movl %eax,-12(%ebp)
        movl %edx,-8(%ebp)
        movl (%ecx),%eax
        xorl %edx,%edx
        pushl %edx
        pushl %eax
        movl -12(%ebp),%eax
        movl -8(%ebp),%edx
        pushl %edx
        pushl %eax
        call __umoddi3
        movl 8(%ebp),%edx
        addl $16,%esp
        movl %eax,(%ebx,%edi,4)
        incl %esi
        movl 4(%edx),%eax
        movl %eax,%edi
        cmpl %edi,%esi
        jb .L11