define_insn : order of matching patterns

[jeroen dobbelaere]

Alexandre Oliva wrote:

> On Dec  4, 2001, jeroen dobbelaere <jeroen.dobbelaere@acunia.com> wrote:
> 
> 
>>1. Why doesn't the original pattern ('*mulhisi3addsi_left') get a match ?
>>
> 
> Read about pattern canonicalization in the GCC manual.
> 
> 

Ok. Found it there :

<http://gcc.gnu.org/onlinedocs/gcc_21.html#SEC246>

     * For commutative and comparison operators, [..]
       if only one operand is a neg, not, mult, plus, or minus expression, it will be the first operand.

Thanks !

--
Jeroen Dobbelaere
Embedded Software Engineer

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