From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=qPMk=IA=gmail.com=nokanaran@sourceware.org>
Received: from mail-yw1-x1134.google.com (mail-yw1-x1134.google.com [IPv6:2607:f8b0:4864:20::1134])
	by sourceware.org (Postfix) with ESMTPS id F1C493858D37
	for <gcc-help@gcc.gnu.org>; Thu, 21 Dec 2023 19:32:11 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F1C493858D37
Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com
ARC-Filter: OpenARC Filter v1.0.0 sourceware.org F1C493858D37
Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::1134
ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1703187133; cv=none;
	b=CrxXsOJn6TUdiT5zaArlzMzbI+pPmhIGbKyxG/oWKVGlKj0jPWTO1GQ2arbHoT2Pc/n4DM9TpeDdsFivKbJSQeUTEcoetekOCxd1nSV49WcBYhf4/893Sozdm0Ddx+Ue4wMY0MYgf1e/vL9JJqgY2j9O6PR6ZrhQMjU7424J2P8=
ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key;
	t=1703187133; c=relaxed/simple;
	bh=NcR5CuMf+tc/BNmdzdbWz9CAgoV42PIOiRFxVjyWDC4=;
	h=DKIM-Signature:MIME-Version:From:Date:Message-ID:Subject:To; b=BiOyqr3h4/X/DdypvvznD9RRSTOHs+wpteZ1ki9YNwEi2AWcTghxtFJ9kSfg7RAYyaKrER++2ii0rKXEndbbNNL5aSKb4JONfjx2/uQQKiVTJW4Pqt08OhIH/O3+Xw4c+BodFzohXNK/SUpZxu4CdPx6pEBhahnKeN01xRqAWwU=
ARC-Authentication-Results: i=1; server2.sourceware.org
Received: by mail-yw1-x1134.google.com with SMTP id 00721157ae682-5d05ff42db0so12282017b3.2
        for <gcc-help@gcc.gnu.org>; Thu, 21 Dec 2023 11:32:11 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20230601; t=1703187131; x=1703791931; darn=gcc.gnu.org;
        h=to:subject:message-id:date:from:mime-version:from:to:cc:subject
         :date:message-id:reply-to;
        bh=g3juWKSuCqBbeNDFvV765JqP6a0IT/nHkgJW6iIN6+E=;
        b=Cth5/DvizCbMbMpTwEOh64gWS3/Dtm5Lw0YIEtwJHNRz3oHfBjiALRpHqgbXcU//mR
         a83okF+Bnbv1I9nyhyB4hmDE4UjD018k5QaeHPyMpM9qqhAKJOyW2lvP76vcqXCc22OE
         PSbOPNa5BNrP/zhp3TlvdqnI7E/UJ9TI43YEYkkvgI5Qrpcj6BgOfo85en+UB9+tSIpN
         CIZ34z3R3wYAi7Pzl0e3iaIzxo/kcS/rgkNB3t3KOB/YTbYo1k2N7frSqsxTVZOs82NK
         jB9PzGuQ3rG9badzJmIjkKuyFUjqIwoW22oDUnR1YKVePYCdPxs7R69osuZ46vRv1pzI
         mUrQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20230601; t=1703187131; x=1703791931;
        h=to:subject:message-id:date:from:mime-version:x-gm-message-state
         :from:to:cc:subject:date:message-id:reply-to;
        bh=g3juWKSuCqBbeNDFvV765JqP6a0IT/nHkgJW6iIN6+E=;
        b=eF9bBas5qJFRMpWnOX9V+aDAHYhiWM5XUngrqmlGpfDjo8GbZC6T+8BM8Ed953P0s3
         BAC25wbDpX8h1wzhIt+YrkugARP4jyPEkP60p+pVpNmK8/ITfnhG0CVndo9t7ioNp2LY
         Jx5Wf/E++3xb8HLuQs9Vx9hJz6/aKMKr1KKGbVcZmIh7jMcwujBlusKJeYrHi/ZQGqp3
         gIHpuSjBQyGzHWS1iKpNcAm9F1ffhD9qtt85c4D9B9Y0fuY6LSQTyF1CVyH9GNPp4jtz
         Uox8oml8Hu6ESrTszuC50IhsMI0Tg0M75HMTmjHgxSdj4YoYrUF2ogZe/IwKkVVcm63N
         Gcag==
X-Gm-Message-State: AOJu0YyrfIA7div8mzrv5lNQ0F5X7/EA+CnoO1GSFH08admdptGmrnOW
	AURTG+5pHjzSTXbGo6DVAXNfFxtcfHuBhuFU/8/4+mpGGZE=
X-Google-Smtp-Source: AGHT+IGx8dPi3ejE1yTy6Yud7UEv2U1tnTRf8dnPFsAAOfj8PNQ8NIonU/mIY7v03gkLXRYm1nkSR1oRb/jmP0z5jEs=
X-Received: by 2002:a81:4e8c:0:b0:5e7:4558:aef9 with SMTP id
 c134-20020a814e8c000000b005e74558aef9mr307502ywb.22.1703187131111; Thu, 21
 Dec 2023 11:32:11 -0800 (PST)
MIME-Version: 1.0
From: Aran Nokan <nokanaran@gmail.com>
Date: Thu, 21 Dec 2023 20:32:00 +0100
Message-ID: <CAKHt_YZXP4EXkUbi+pjMciF37GFYX825sWiTwMwZ7sWtNqGUiA@mail.gmail.com>
Subject: GCC Optimization Levels - Seeking Insights
To: gcc-help@gcc.gnu.org
Content-Type: multipart/alternative; boundary="000000000000ef9f48060d0a2771"
X-Spam-Status: No, score=0.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE 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: <gcc-help.gcc.gnu.org>

--000000000000ef9f48060d0a2771
Content-Type: text/plain; charset="UTF-8"

Hello GCC Community,

I recently conducted an experiment where I tested the impact of different
GCC optimization levels on the performance of a code
<https://github.com/leechwort/levenberg-maquardt-example>. I observed that
higher optimization levels didn't necessarily result in faster code
execution.

Is it correct or I have made a mistake? Do we have any other parameters for
optimization?


My make file was as follows:


CC=gcc
> CFLAGS_COMMON=-I.
> LDLAGS=-lm
> DEPS = levmarq.h
> OBJ = main.o levmarq.o
>
> %.o: %.c $(DEPS)
>         $(CC) -c -o $@ $< $(CFLAGS) $(LDLAGS)
>
> main: $(OBJ)
>         gcc -o $@ $^ $(CFLAGS) $(LDLAGS)
>
> # No optimization
> main_no_opt: CFLAGS += -O0
> main_no_opt: $(OBJ)
>         gcc -o $@ $^ $(CFLAGS) $(LDLAGS)
>
> # Basic optimization
> main_opt1: CFLAGS += -O1
> main_opt1: $(OBJ)
>         gcc -o $@ $^ $(CFLAGS) $(LDLAGS)
>
> # Moderate optimization
> main_opt2: CFLAGS += -O2
> main_opt2: $(OBJ)
>         gcc -o $@ $^ $(CFLAGS) $(LDLAGS)
>
> # High optimization
> main_opt3: CFLAGS += -O3
> main_opt3: $(OBJ)
>         gcc -o $@ $^ $(CFLAGS) $(LDLAGS)
>
> # Clean rule
> clean:
>         rm -f *.o main main_no_opt main_opt2 main_opt3
>

Best regards,
Aran

--000000000000ef9f48060d0a2771--