[PATCH][ARM][stage-1] Initialise cost to COSTS_N_INSNS (1) and increment in arm rtx costs

[Kyrill Tkachov]

Ping.
https://gcc.gnu.org/ml/gcc-patches/2015-04/msg01130.html

Thanks,
Kyrill

On 21/04/15 10:11, Kyrill Tkachov wrote:
> Hi all,
>
> This is the first of a series to clean up and simplify the arm rtx costs function.
> This patch initialises the cost to COSTS_N_INSNS (1) at the top and increments it when appropriate
> in the rest of the function. This makes it more similar to the aarch64 rtx costs function and saves
> us the trouble of having to remember to initialise the cost to COSTS_N_INSNS (1) in each case of the
> switch statement.
>
> Bootstrapped and tested arm-none-linux-gnueabihf.
> Compiled some large programs with no codegen difference, except some DIV synthesis algorithms were changed,
> presumably due to the cost of SDIV/UDIV, which is now being correctly calculated (before it was missing the
> baseline COSTS_N_INSNS (1)).
>
> Ok for trunk?
>
> Thanks,
> Kyrill
>
> 2015-04-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>
>       * config/arm/arm.c (arm_new_rtx_costs): Initialise cost to
>       COSTS_N_INSNS (1) and increment it appropriately throughout the
>       function.