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 <f...@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 <f...@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);
>
