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Re: [PATCH] Add PAREN_EXPR

Richard Guenther wrote:
> On Tue, 19 Feb 2008, Tobias Burnus wrote:
> 
>> FX wrote:
>>>>         * trans-expr.c (gfc_conv_expr_op): Expand INTRINSIC_PARENTHESES
>>>>         as unary PAREN_EXPR for real and complex typed expressions.
>>>>         * options.c (gfc_init_options): Enable flag_associative_math if
>>>>         it isn't disabled automatically.
>>>>
>>>>         * gfortran.dg/reassoc_1.f90: New testcase.
>>>>         * gfortran.dg/reassoc_2.f90: Likewise.
>>>>     
>>> Fortran part is OK. Thanks!
>>>   
>> Thanks also from me. Is it possible to add a flag for disabling the
>> PAREN_EXPR? I'm sure some users want to have this to gain some speed. (For
>> a/(b*c) the () are often only used because it is easier to read than a/b/c;
>> for such programs it might be useful to be able to disable it.)
>>

How would the version with 2 divisions become faster than the original?
It seems more likely that the original version would have been written for
improved speed, or to avoid inconsistencies according to whether the
version with 2 divides is optimized.
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