From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from server28.superhosting.bg (server28.superhosting.bg [217.174.156.11]) by sourceware.org (Postfix) with ESMTPS id EEC5A3858C3A for ; Tue, 7 May 2024 07:23:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org EEC5A3858C3A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=dinux.eu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=dinux.eu ARC-Filter: OpenARC Filter v1.0.0 sourceware.org EEC5A3858C3A Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=217.174.156.11 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1715066591; cv=none; b=cVTkTAciFGcmXnfVHI8RQsgilloUQSZNTgKbK7oyzlS+PrPYmfNYTT+YbWq2WvriqNlyhfsO2KF331cPnrba0AVKIntxVy6KGItE+B2d2dWEkOBl+HgqpGMW3bJ5hiGOX2P2rD4zDwB0BU6L+dhJ4p0/qqmlcvYTYFmJ7/17kpo= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1715066591; c=relaxed/simple; bh=R+mqGj2ooPVCMGFxU3BO+eYmDlUdgBZeaLVXCfALwl4=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=qwZPJe6UEPzswypW18x34gn/jt7oA5WKp5O5tsCawMRaJWkhozLrL8WPGSvdYhE/Stnk2HUsOmq/TtMqWOFzv0Ygjacv1mv9bE9u0AS4fcdybrVtzcwOwTstc/fQ2G7+VUYq6BsE2MDeoy3+t7k8AAipSp315GNZnmcfvZjKm00= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=dinux.eu; s=default; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=nvIBqKC8MnNBNtUBkO+WxVKu+gK/Z6b7/8NzPYuFb/U=; b=VxxcvXsARDir4bz1ZKI7sfrvEv CJvIC+oDKrJdxuYkapunMc2naHF+m2rAQoAahwqVyU2bR6y7LypDVNoNA1/2tSfQTvWUK0YeEk2nL B4hpfXtLe1qDlmknVJ2Ssn0MsQ+ke6UNKWIYOGuDodBvwk45hUA0yv62zWRvzfoVi8LGfH5y/0dcT 9AusXuYNBmBi5zNYwY4vpz6TjsEeiRjb3H6UZRPsyfkKO3CQ7bQRO2aHgvwdM+d0FkoELPnURXph9 KrMVdQYZQciEyTe8UShvzJFew2IIglgxw+LLm7iGDAWWrKy6gBKcMQ1Sb2fycmSb5SQJ/A1oMcFNM /6BlqL0w==; Received: from [95.42.20.142] (port=48504 helo=kendros.lan) by server28.superhosting.bg with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1s4FAI-00067X-1d; Tue, 07 May 2024 10:23:08 +0300 From: Dimitar Dimitrov To: gcc-patches@gcc.gnu.org Cc: Dimitar Dimitrov Subject: [COMMITTED 5/9] pru: Skip register save if function will not return Date: Tue, 7 May 2024 10:22:37 +0300 Message-ID: X-Mailer: git-send-email 2.45.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server28.superhosting.bg X-AntiAbuse: Original Domain - gcc.gnu.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - dinux.eu X-Get-Message-Sender-Via: server28.superhosting.bg: authenticated_id: dimitar@dinux.eu X-Authenticated-Sender: server28.superhosting.bg: dimitar@dinux.eu X-Source: X-Source-Args: X-Source-Dir: X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_SHORT,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: There is no need to store callee-saved registers in prologue if the function would never return. Size optimization is paramount for the microcontroller-class PRU. Some backends save some registers for noreturn functions. But for PRU debuggability is a less concern because GDB has not been ported yet for PRU. gcc/ChangeLog: * config/pru/pru.cc (prologue_saved_reg_p): Skip saving if function will not return. gcc/testsuite/ChangeLog: * gcc.target/pru/noreturn-prologue-1.c: New test. * gcc.target/pru/noreturn-prologue-2.c: New test. Signed-off-by: Dimitar Dimitrov --- gcc/config/pru/pru.cc | 4 ++++ gcc/testsuite/gcc.target/pru/noreturn-prologue-1.c | 10 ++++++++++ gcc/testsuite/gcc.target/pru/noreturn-prologue-2.c | 11 +++++++++++ 3 files changed, 25 insertions(+) create mode 100644 gcc/testsuite/gcc.target/pru/noreturn-prologue-1.c create mode 100644 gcc/testsuite/gcc.target/pru/noreturn-prologue-2.c diff --git a/gcc/config/pru/pru.cc b/gcc/config/pru/pru.cc index a76451f4223..e5ec398d2db 100644 --- a/gcc/config/pru/pru.cc +++ b/gcc/config/pru/pru.cc @@ -443,6 +443,10 @@ prologue_saved_reg_p (int regno) { gcc_assert (GP_REG_P (regno)); + /* Do not save the register if function will not return. */ + if (TREE_THIS_VOLATILE (current_function_decl)) + return false; + if (df_regs_ever_live_p (regno) && !call_used_or_fixed_reg_p (regno)) return true; diff --git a/gcc/testsuite/gcc.target/pru/noreturn-prologue-1.c b/gcc/testsuite/gcc.target/pru/noreturn-prologue-1.c new file mode 100644 index 00000000000..af69e52d925 --- /dev/null +++ b/gcc/testsuite/gcc.target/pru/noreturn-prologue-1.c @@ -0,0 +1,10 @@ +/* Ensure prologues are not generated for noreturn functions. */ +/* { dg-do assemble } */ +/* { dg-options "-Os" } */ +/* { dg-final { object-size text == 0 } } */ + +void test(void) +{ + asm volatile ("# \n\t" : : : "r5", "r10"); + __builtin_unreachable (); +} diff --git a/gcc/testsuite/gcc.target/pru/noreturn-prologue-2.c b/gcc/testsuite/gcc.target/pru/noreturn-prologue-2.c new file mode 100644 index 00000000000..8d12a9c462b --- /dev/null +++ b/gcc/testsuite/gcc.target/pru/noreturn-prologue-2.c @@ -0,0 +1,11 @@ +/* Ensure prologues are not generated for noreturn functions. */ +/* { dg-do assemble } */ +/* { dg-options "-Os" } */ +/* { dg-final { object-size text == 4 } } */ + +void test(void) +{ + asm volatile ("# \n\t" : : : "r0", "r9"); + for (;;) + ; +} -- 2.45.0