Re: [PATCH v4] mips: make rtl if-conversion more common

Hi all,

This is a gentle ping.

Regards,
Radosav

On 7/15/26 19:03, Radosav Krunic wrote:
> It tunes ifcvt parameters so that we get if-conversion in more cases.
>
> gcc/
>
> 	* config/mips/mips.cc (mips_rtx_costs): Reduce cost of
> 	if_then_else pattern.
> 	(mips_max_noce_ifcvt_seq_cost): New function. Decrease
> 	maximum permissible cost for the unconditional sequence which
> 	should be generated during if-conversion (for all non-r6
> 	targets). This disables if-conversion for non-r6 targets in
> 	branch-cost-1.c test.
> 	(TARGET_MAX_NOCE_IFCVT_SEQ_COST): Define hook.
>
> gcc/testsuite/
>
> 	* gcc.target/mips/branch-cost-1.c: Disable for -Os.
>
> Signed-off-by: Dragan Mladjenovic <[email protected]>
> Signed-off-by: Mihailo Stojanovic <[email protected]>
> Signed-off-by: Faraz Shahbazker <[email protected]>
> Signed-off-by: Aleksandar Rakic <[email protected]>
> Signed-off-by: Radosav Krunic <[email protected]>
> ---
>   v4: Fix the formatting and remove the conversion_profitable_hook.
>
>   gcc/config/mips/mips.cc                       | 34 +++++++++++++++++++
>   gcc/testsuite/gcc.target/mips/branch-cost-1.c |  2 +-
>   2 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
> index 80828ed20af..9d7c86fffca 100644
> --- a/gcc/config/mips/mips.cc
> +++ b/gcc/config/mips/mips.cc
> @@ -67,6 +67,7 @@ along with GCC; see the file COPYING3.  If not see
>   #include "rtl-iter.h"
>   #include "flags.h"
>   #include "opts.h"
> +#include "ifcvt.h"
>   
>   /* This file should be included last.  */
>   #include "target-def.h"
> @@ -4796,6 +4797,12 @@ mips_rtx_costs (rtx x, machine_mode mode, int outer_code,
>   	}
>         return false;
>   
> +    case IF_THEN_ELSE:
> +      if (reg_or_0_operand (XEXP (x, 1), VOIDmode)
> +	  || reg_or_0_operand (XEXP (x, 2), VOIDmode))
> +	*total = 0;
> +      return false;
> +
>       default:
>         return false;
>       }
> @@ -23359,6 +23366,30 @@ mips_bit_clear_p (enum machine_mode mode, unsigned HOST_WIDE_INT m)
>     return false;
>   }
>   
> +/* Implement TARGET_MAX_NOCE_IFCVT_SEQ_COST.  */
> +
> +static unsigned int
> +mips_max_noce_ifcvt_seq_cost (edge e)
> +{
> +  bool predictable_p = predictable_edge_p (e);
> +
> +  /* If we have a parameter set, use that, otherwise take a guess using
> +     BRANCH_COST.  */
> +  if (predictable_p)
> +    {
> +      if (OPTION_SET_P (param_max_rtl_if_conversion_predictable_cost))
> +	return param_max_rtl_if_conversion_predictable_cost;
> +    }
> +  else
> +    {
> +      if (OPTION_SET_P (param_max_rtl_if_conversion_unpredictable_cost))
> +	return param_max_rtl_if_conversion_unpredictable_cost;
> +    }
> +
> +  return BRANCH_COST (true, predictable_p)
> +     * COSTS_N_INSNS (mips_isa_rev == 6 ? 4 : 3);
> +}
> +
>   /* define TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY */
>   
>   /* The MIPS function start is implemented in the prologue function.
> @@ -23687,6 +23718,9 @@ mips_print_patchable_function_entry (FILE *file ATTRIBUTE_UNUSED,
>   #undef TARGET_DOCUMENTATION_NAME
>   #define TARGET_DOCUMENTATION_NAME "MIPS"
>   
> +#undef TARGET_MAX_NOCE_IFCVT_SEQ_COST
> +#define TARGET_MAX_NOCE_IFCVT_SEQ_COST mips_max_noce_ifcvt_seq_cost
> +
>   #undef TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY
>   #define TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY \
>   mips_print_patchable_function_entry
> diff --git a/gcc/testsuite/gcc.target/mips/branch-cost-1.c b/gcc/testsuite/gcc.target/mips/branch-cost-1.c
> index 7f7ebbe5fc9..006a29a7361 100644
> --- a/gcc/testsuite/gcc.target/mips/branch-cost-1.c
> +++ b/gcc/testsuite/gcc.target/mips/branch-cost-1.c
> @@ -1,5 +1,5 @@
>   /* { dg-options "-mbranch-cost=1 (HAS_MOVN)" } */
> -/* { dg-skip-if "code quality test" { *-*-* } { "-O0" } { "" } } */
> +/* { dg-skip-if "code quality test" { *-*-* } { "-O0" "-Os" } { "" } } */
>   NOMIPS16 int
>   foo (int x, int y, int z, int k)
>   {