Re: [PATCH] Do not propagate self-dependent value (PR ipa/93763)

[Martin Jambor <mjambor@suse.cz>]

Hi,

On Tue, Feb 18 2020, Feng Xue OS wrote:
> Currently, for self-recursive call, we never use value originated from non-passthrough
> jump function as source to avoid propagation explosion, but self-dependent value is
> missed. This patch is made to fix the bug.
>
> Bootstrapped/regtested on x86_64-linux and aarch64-linux.
>
> Feng
> ---
> 2020-02-18  Feng Xue  <fxue@os.amperecomputing.com>
>
>         PR ipa/93763
>         * ipa-cp.c (self_recursively_generated_p): Mark self-dependent value as
>         self-recursively generated.

Honza, this is OK.

Thanks,

Martin



> From 1ff803f33de0fe86d526deb23af2d08c15028ff9 Mon Sep 17 00:00:00 2001
> From: Feng Xue <fxue@os.amperecomputing.com>
> Date: Mon, 17 Feb 2020 17:07:04 +0800
> Subject: [PATCH] Do not propagate self-dependent value (PR ipa/93763)
>
> ---
>  gcc/ipa-cp.c                       | 10 ++++---
>  gcc/testsuite/g++.dg/ipa/pr93763.C | 15 ++++++++++
>  gcc/testsuite/gcc.dg/ipa/pr93763.c | 46 ++++++++++++++++++++++++++++++
>  3 files changed, 67 insertions(+), 4 deletions(-)
>  create mode 100644 gcc/testsuite/g++.dg/ipa/pr93763.C
>  create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93763.c
>
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index 4f5b72e6994..1d0c1ac0f35 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -1897,8 +1897,8 @@ ipcp_lattice<valtype>::add_value (valtype newval, cgraph_edge *cs,
>  }
>  
>  /* Return true, if a ipcp_value VAL is orginated from parameter value of
> -   self-feeding recursive function by applying non-passthrough arithmetic
> -   transformation.  */
> +   self-feeding recursive function via some kind of pass-through jump
> +   function.  */
>  
>  static bool
>  self_recursively_generated_p (ipcp_value<tree> *val)
> @@ -1909,10 +1909,12 @@ self_recursively_generated_p (ipcp_value<tree> *val)
>      {
>        cgraph_edge *cs = src->cs;
>  
> -      if (!src->val || cs->caller != cs->callee->function_symbol ()
> -	  || src->val == val)
> +      if (!src->val || cs->caller != cs->callee->function_symbol ())
>  	return false;
>  
> +      if (src->val == val)
> +	continue;
> +
>        if (!info)
>  	info = IPA_NODE_REF (cs->caller);
>