Re: [RFA][PR rtl-optimization/70263] Fix creation of new REG_EQUIV notes

[Bernd Schmidt <bschmidt at redhat dot com>]

On 03/17/2016 06:37 PM, Jeff Law wrote:
> +  bitmap seen_insns;
>
> +  seen_insns = BITMAP_ALLOC (NULL);

You could save an allocation here by making this a bitmap_head and using 
bitmap_initialize.

> +      bitmap_set_bit (seen_insns, INSN_UID (insn));
> +
>        if (! INSN_P (insn))
>  	continue;
>
> @@ -3646,7 +3656,8 @@ update_equiv_regs (void)
>  	  && ! find_reg_note (XEXP (reg_equiv[regno].init_insns, 0),
>  			      REG_EQUIV, NULL_RTX)
>  	  && ! contains_replace_regs (XEXP (dest, 0))
> -	  && ! pdx_subregs[regno])
> +	  && ! pdx_subregs[regno]
> +	  && ! bitmap_bit_p (seen_insns, INSN_UID (insn)))

This looks odd to me. Isn't this condition always false? Did you want to 
test the init_insn?


Bernd