From: Eric Botcazou <botcazou@adacore.com>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] Reduce DF computation at -O0
Date: Thu, 06 Oct 2022 19:25:53 +0200 [thread overview]
Message-ID: <2601473.BddDVKsqQX@fomalhaut> (raw)
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Hi,
even at -O0 there may be a fair amount of DF computation performed when
compiling large units and part of it appears to be useless.
Bootstrapped/regtested on x86-64/Linux, OK for the mainline?
2022-10-06 Eric Botcazou <ebotcazou@adacore.com>
* function.cc (thread_prologue_and_epilogue_insns): Update only entry
and exit blocks when not optimizing. Remove dead statement.
--
Eric Botcazou
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diff --git a/gcc/function.cc b/gcc/function.cc
index 5498a712c4a..6474a663b30 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -6249,10 +6249,15 @@ thread_prologue_and_epilogue_insns (void)
}
}
- /* Threading the prologue and epilogue changes the artificial refs
- in the entry and exit blocks. */
- epilogue_completed = 1;
- df_update_entry_exit_and_calls ();
+ /* Threading the prologue and epilogue changes the artificial refs in the
+ entry and exit blocks, and may invalidate DF info for tail calls. */
+ if (optimize)
+ df_update_entry_exit_and_calls ();
+ else
+ {
+ df_update_entry_block_defs ();
+ df_update_exit_block_uses ();
+ }
}
/* Reposition the prologue-end and epilogue-begin notes after
next reply other threads:[~2022-10-06 17:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-06 17:25 Eric Botcazou [this message]
2022-10-07 6:07 ` Richard Biener
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