From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2a07:de40:b251:101:10:150:64:1]) by sourceware.org (Postfix) with ESMTPS id 8990C385840F for ; Fri, 24 Nov 2023 09:20:04 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8990C385840F Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 8990C385840F Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a07:de40:b251:101:10:150:64:1 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1700817606; cv=none; b=XW1Jrq5t/D01EDZl6tD4QGlIkcHPNlZyjExnDop3h11ydNQxXpWiiNVuLnaWtPyxz2XD8iv72R8XYK5ftYe3wBR0gfpAf4+tXBTfo15LGwJxpa+mQq+ItsqLgLz2fUtWWMasrlMYNWhiqQat+gHnOHuGn10dEL81XFYEQa7QXTY= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1700817606; c=relaxed/simple; bh=DR9+btXba5xUeszLBz+drN56pZnTNA44HavQzoKrKTo=; h=DKIM-Signature:DKIM-Signature:Date:From:To:Subject:Message-ID: MIME-Version; b=cv0pIzVRdDJBDrmdcYCz0Rmwq1ccx06WVCsi2Dwh+zKq4M42i8KtrXSAa5fg2FV5Jb9M3lMyo/F6VruKlQjUzRAhuxYAHGdQYH1wNmJTVl4jWEjHsqlu17HjxLpO0HJrbUZxApeW7OwssD3xrNchlH9mSU/RXjmDElzGMjuo5mA= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from imap2.dmz-prg2.suse.org (imap2.dmz-prg2.suse.org [10.150.64.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6FA6C21CAF; Fri, 24 Nov 2023 09:20:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1700817602; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=iBzsjifkPXhE6+akUGGkoHAjJJlVXA6HnH0Pg623CfI=; b=eupL3HNxlvXAcF/SA90+7JFb25xoR4pQhByPqdLRjnsNdHluvmzoBiVuooVfK8sZA/9KRw YxxC+J8g+aLyb67HxEyGattY2pcPudAc+YRx6V9mrGeg9OwuERG56QIzh3vN9/kHvUdY9j UKTHo6ddRaY90TD2M/fSq/WRcnzVX/g= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1700817602; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=iBzsjifkPXhE6+akUGGkoHAjJJlVXA6HnH0Pg623CfI=; b=eYRmuw6nmsDM0BWGwA38lJ9EoWPdoC0Ci5T+JGXY5z5hA5DodKQfGLz0JmCt/W1B0v2JP+ iV/OQ93KgGcQ3qCQ== Received: from imap2.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap2.dmz-prg2.suse.org (Postfix) with ESMTPS id 339E2132E2; Fri, 24 Nov 2023 09:20:02 +0000 (UTC) Received: from dovecot-director2.suse.de ([10.150.64.162]) by imap2.dmz-prg2.suse.org with ESMTPSA id AZ9xCcJqYGVFTgAAn2gu4w (envelope-from ); Fri, 24 Nov 2023 09:20:02 +0000 Date: Fri, 24 Nov 2023 10:20:01 +0100 (CET) From: Richard Biener To: Jakub Jelinek cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] lower-bitint: Lower FLOAT_EXPR from BITINT_TYPE INTEGER_CST [PR112679] In-Reply-To: Message-ID: <0773955o-4086-35o9-o657-072349688qsp@fhfr.qr> References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Authentication-Results: smtp-out1.suse.de; none X-Spam-Score: -4.30 X-Spam-Level: X-Spamd-Result: default: False [-4.30 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; RCPT_COUNT_TWO(0.00)[2]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,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: On Fri, 24 Nov 2023, Jakub Jelinek wrote: > Hi! > > The bitint lowering pass only does something if it sees BITINT_TYPE (medium, > large, huge) SSA_NAMEs. In the past I've already ran into one special case > where the above doesn't work well, if there is a store of medium/large/huge > BITINT_TYPE INTEGER_CST into memory, there might not be any BITINT_TYPE > SSA_NAMEs in the function, yet we need to lower. This has been solved by > also checking for SSA_NAME_IS_VIRTUAL_OPERAND if at the vdef there isn't > such a store (the whole intent is make the pass as cheap as possible in the > currently very likely case that the IL doesn't have any BITINT_TYPEs at > all). > And the following testcase shows a similar problem. With -frounding-math > we don't fold some of FLOAT_EXPRs with INTEGER_CST operands, and if those > INTEGER_CSTs are medium/large/huge BITINT_TYPEs, we need to either cast > the INTEGER_CST to corresponding INTEGER_TYPE (for medium) or lower to > internal fn call which is later turned into libgcc call (for large/huge). > The following patch does that, but of course admittedly this discovery > of stores and FLOAT_EXPRs means we already look through quite a few > SSA_NAME_DEF_STMTs even when BITINT_TYPEs never appear. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2023-11-23 Jakub Jelinek > > PR middle-end/112679 > * gimple-lower-bitint.cc (gimple_lower_bitint): Also stop first loop on > floating point SSA_NAME set in FLOAT_EXPR assignment from BITINT_TYPE > INTEGER_CST. Set has_large_huge for those if that BITINT_TYPE is large > or huge. Set kind to such FLOAT_EXPR assignment rhs1 BITINT_TYPE's kind. > > * gcc.dg/bitint-42.c: New test. > > --- gcc/gimple-lower-bitint.cc.jj 2023-11-23 14:30:02.830662509 +0100 > +++ gcc/gimple-lower-bitint.cc 2023-11-23 16:17:59.217298778 +0100 > @@ -5635,6 +5635,21 @@ gimple_lower_bitint (void) > break; > } > } > + /* Similarly, e.g. with -frounding-math casts from _BitInt INTEGER_CSTs > + to floating point types need to be rewritten. */ > + else if (SCALAR_FLOAT_TYPE_P (type)) > + { > + gimple *g = SSA_NAME_DEF_STMT (s); > + if (is_gimple_assign (g) && gimple_assign_rhs_code (g) == FLOAT_EXPR) > + { I think this would combine with the virtual operand code up to the is_gimle_assign () check. But I also wonder if when you disable enough passes you could for example see switch (bit-int-cst) or if (bit-int-cst ...) as well? Given we have PROP_gimple_lbitint couldn't we set that optimistically say during gimplification when we didn't see any bit-int, making sure to clear the property during inlining when the inlined function doesn't have it set? Or maybe require frontends to opt-in into features that require additional processing, indicating that with a bit in struct function (or a flag on the decl or via a langhook)? There's other passes that we could gate (coroutine stuff, omp stuff?) Otherwise the patch looks OK, I'm just questioning the way we try to avoid running it. Thanks, Richard. > + tree t = gimple_assign_rhs1 (g); > + if (TREE_CODE (t) == INTEGER_CST > + && TREE_CODE (TREE_TYPE (t)) == BITINT_TYPE > + && (bitint_precision_kind (TREE_TYPE (t)) > + != bitint_prec_small)) > + break; > + } > + } > } > if (i == num_ssa_names) > return 0; > @@ -5855,6 +5870,21 @@ gimple_lower_bitint (void) > has_large_huge = true; > } > } > + /* Similarly, e.g. with -frounding-math casts from _BitInt INTEGER_CSTs > + to floating point types need to be rewritten. */ > + else if (SCALAR_FLOAT_TYPE_P (type)) > + { > + gimple *g = SSA_NAME_DEF_STMT (s); > + if (is_gimple_assign (g) && gimple_assign_rhs_code (g) == FLOAT_EXPR) > + { > + tree t = gimple_assign_rhs1 (g); > + if (TREE_CODE (t) == INTEGER_CST > + && TREE_CODE (TREE_TYPE (t)) == BITINT_TYPE > + && (bitint_precision_kind (TREE_TYPE (t)) > + >= bitint_prec_large)) > + has_large_huge = true; > + } > + } > } > for (i = first_large_huge; i < num_ssa_names; ++i) > { > @@ -6182,6 +6212,19 @@ gimple_lower_bitint (void) > { > bitint_prec_kind this_kind > = bitint_precision_kind (TREE_TYPE (t)); > + if (this_kind > kind) > + kind = this_kind; > + } > + } > + if (is_gimple_assign (stmt) > + && gimple_assign_rhs_code (stmt) == FLOAT_EXPR) > + { > + t = gimple_assign_rhs1 (stmt); > + if (TREE_CODE (TREE_TYPE (t)) == BITINT_TYPE > + && TREE_CODE (t) == INTEGER_CST) > + { > + bitint_prec_kind this_kind > + = bitint_precision_kind (TREE_TYPE (t)); > if (this_kind > kind) > kind = this_kind; > } > --- gcc/testsuite/gcc.dg/bitint-42.c.jj 2023-11-23 16:50:52.392502318 +0100 > +++ gcc/testsuite/gcc.dg/bitint-42.c 2023-11-23 16:42:08.559881704 +0100 > @@ -0,0 +1,9 @@ > +/* PR middle-end/112679 */ > +/* { dg-do compile { target bitint } } */ > +/* { dg-options "-frounding-math" } */ > + > +float > +foo (void) > +{ > + return 0x353eab28b46b03ea99b84f9736cd8dbe5e986915a0383c3cb381c0da41e31b3621c75fd53262bfcb1b0e6251dbf00f3988784e29b08b65640c263e4d0959832a20e2ff5245be1e60uwb; > +} > > Jakub > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman; HRB 36809 (AG Nuernberg)