From patchwork Thu Feb 17 10:34:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 543928 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11833C4332F for ; Thu, 17 Feb 2022 10:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231827AbiBQKe1 (ORCPT ); Thu, 17 Feb 2022 05:34:27 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235051AbiBQKe0 (ORCPT ); Thu, 17 Feb 2022 05:34:26 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7233311D7A4 for ; Thu, 17 Feb 2022 02:34:09 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 1BFBB1F3A2; Thu, 17 Feb 2022 10:34:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1645094048; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7zhDW9GZgquU5ieSm8OfhmekeuoN6Y5X5AMezo/Oqhg=; b=PS6Bn3FC3oO86wTMeYFXdA2+KYbRwIvKvwsipQKpuXFU43qII5R8IdqWCaUpLVDMaO7EAX KoG/oqMZd3iTVWhFt0i4DhG2QLRJp+k2WE0USXN04UmCg8IaLmyDCsJyuTiuXRAijnMrWu GmxElz1FbKRapQnb+3RDVfJN2UWas3E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1645094048; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7zhDW9GZgquU5ieSm8OfhmekeuoN6Y5X5AMezo/Oqhg=; b=mXWROs2BGYinIs0pDIP2eN8H2o1N5dS027mhT8LsKVYxmJpqnCD67SWUaiVWLgKesyzj6z INYBLEOiCpYm6MBQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id E7A6713DDE; Thu, 17 Feb 2022 10:34:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id eHySN58kDmLQQgAAMHmgww (envelope-from ); Thu, 17 Feb 2022 10:34:07 +0000 From: Thomas Zimmermann To: daniel@ffwll.ch, deller@gmx.de, javierm@redhat.com, geert@linux-m68k.org Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, Thomas Zimmermann Subject: [PATCH 2/2] fbdev: Improve performance of sys_imageblit() Date: Thu, 17 Feb 2022 11:34:05 +0100 Message-Id: <20220217103405.26492-3-tzimmermann@suse.de> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220217103405.26492-1-tzimmermann@suse.de> References: <20220217103405.26492-1-tzimmermann@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Improve the performance of sys_imageblit() by manually unrolling the inner blitting loop and moving some invariants out. The compiler failed to do this automatically. The resulting binary code was even slower than the cfb_imageblit() helper, which uses the same algorithm, but operates on I/O memory. A microbenchmark measures the average number of CPU cycles for sys_imageblit() after a stabilizing period of a few minutes (i7-4790, FullHD, simpledrm, kernel with debugging). The value for CFB is given as a reference. sys_imageblit(), new: 25934 cycles sys_imageblit(), old: 35944 cycles cfb_imageblit(): 30566 cycles In the optimized case, sys_imageblit() is now ~30% faster than before and ~20% faster than cfb_imageblit(). Signed-off-by: Thomas Zimmermann --- drivers/video/fbdev/core/sysimgblt.c | 51 +++++++++++++++++++++------- 1 file changed, 39 insertions(+), 12 deletions(-) diff --git a/drivers/video/fbdev/core/sysimgblt.c b/drivers/video/fbdev/core/sysimgblt.c index a4d05b1b17d7..d70d65af6fcb 100644 --- a/drivers/video/fbdev/core/sysimgblt.c +++ b/drivers/video/fbdev/core/sysimgblt.c @@ -188,23 +188,32 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, { u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel; u32 ppw = 32/bpp, spitch = (image->width + 7)/8; - u32 bit_mask, end_mask, eorx, shift; + u32 bit_mask, eorx; const char *s = image->data, *src; u32 *dst; - const u32 *tab = NULL; - int i, j, k; + const u32 *tab; + size_t tablen; + u32 colortab[16]; + int i, j, k, jdecr; + + if ((uintptr_t)dst1 % 8) + return; switch (bpp) { case 8: tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le; + tablen = 16; break; case 16: tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le; + tablen = 4; break; case 32: - default: tab = cfb_tab32; + tablen = 2; break; + default: + return; } for (i = ppw-1; i--; ) { @@ -217,19 +226,37 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, bit_mask = (1 << ppw) - 1; eorx = fgx ^ bgx; k = image->width/ppw; + jdecr = 8 / ppw; + + for (i = 0; i < tablen; ++i) + colortab[i] = (tab[i] & eorx) ^ bgx; for (i = image->height; i--; ) { dst = dst1; - shift = 8; src = s; - for (j = k; j--; ) { - shift -= ppw; - end_mask = tab[(*src >> shift) & bit_mask]; - *dst++ = (end_mask & eorx) ^ bgx; - if (!shift) { - shift = 8; - src++; + for (j = k; j; j -= jdecr, ++src) { + switch (ppw) { + case 4: /* 8 bpp */ + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; + break; + case 2: /* 16 bpp */ + *dst++ = colortab[(*src >> 6) & bit_mask]; + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 2) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; + break; + case 1: /* 32 bpp */ + *dst++ = colortab[(*src >> 7) & bit_mask]; + *dst++ = colortab[(*src >> 6) & bit_mask]; + *dst++ = colortab[(*src >> 5) & bit_mask]; + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 3) & bit_mask]; + *dst++ = colortab[(*src >> 2) & bit_mask]; + *dst++ = colortab[(*src >> 1) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; + break; } } dst1 += p->fix.line_length;