From: "Günter Reusing" <guenter DOT reusing AT web DOT de>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Optimization
Date: Wed, 18 Sep 2002 07:35:49 +0200
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I should have added: The same effect happens with GCC 3.0,3.2 and 3.2.

> Can anyone help on optimization of C++ code.
> With -O3 and all other optimization options I tried I'm stuck with
redundant
> code.
> A typical example (output after compiler and assembler run) :
>
> /APP
>     fsincos
> /NO_APP
>     sall $3, %ecx
>     movl (%eax), %esi
> *     fsts -56(%ebp)
>     fxch %st(1)
> **     fsts -52(%ebp)
>     addl %ecx, %esi
> *     movl -56(%ebp), %eax
> **     movl -52(%ebp), %ebx
> **     movl %ebx, 4(%esi)
> *     movl %eax, (%esi)
>     movl 8(%ebp), %eax
>     leal 0(,%edi,8), %ebx
>     fld %st(1)
>     fxch %st(1)
>
> The lines marked with * repective ** show unneccesarry redundant moves.
> Which options can solve that?
>
>
>