From patchwork Wed Oct 27 02:16:11 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yao Qi X-Patchwork-Id: 69313 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) by ozlabs.org (Postfix) with SMTP id 2E379B6F10 for ; Wed, 27 Oct 2010 13:16:24 +1100 (EST) Received: (qmail 6266 invoked by alias); 27 Oct 2010 02:16:22 -0000 Received: (qmail 6257 invoked by uid 22791); 27 Oct 2010 02:16:21 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL, BAYES_00, T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 27 Oct 2010 02:16:16 +0000 Received: (qmail 21653 invoked from network); 27 Oct 2010 02:16:14 -0000 Received: from unknown (HELO ?10.123.1.71?) (yao@127.0.0.2) by mail.codesourcery.com with ESMTPA; 27 Oct 2010 02:16:14 -0000 Subject: Re: [patch 2/3] tm.texi documentation on macro PREFERRED_RENAME_CLASS From: Yao Qi To: "Joseph S. Myers" Cc: gcc-patches@gcc.gnu.org In-Reply-To: References: <4CBFE0BD.3080807@codesourcery.com> <4CBFE30C.7090308@codesourcery.com> Date: Wed, 27 Oct 2010 10:16:11 +0800 Message-ID: <1288145771.1793.103.camel@yaolp> Mime-Version: 1.0 X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org On Thu, 2010-10-21 at 22:04 +0000, Joseph S. Myers wrote: > tm.texi is a generated file. You need to patch tm.texi.in and regenerate > tm.texi. > > In general new target macros should be avoided in favour of hooks (whose > documentation source should be in target.def with a minimal @hook > reference in tm.texi.in) unless one of the following applies: Joseph, It is patch 2 here, which adds target hook, doc and uses target hook. This patch (patch 2) is dependent on patch 1 (http://gcc.gnu.org/ml/gcc-patches/2010-10/msg02197.html) No regression when patch 1 and patch 2 are applied on x86_64-unknown-gnu-linux. OK for mainline? Yao Qi CodeSourcery yao@codesourcery.com (650) 331-3385 x739 gcc/ * target.def: New hook preferred_rename_class. * targhook.c (default_preferred_rename_class): New. * targhook.h: Declare it. * regrename.c (regrename_optimize): Call target hook preferred_rename_class to rename register class. * doc/tm.texi.in: New hook TARGET_PREFERRED_RENAME_CLASS. diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index a9592b1..0983a2d 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -2585,6 +2585,19 @@ only if neither labeling works. This macro also has strict and non-strict variants. @end defmac +@hook TARGET_PREFERRED_RENAME_CLASS +A target hook that places additional restrictions on the register +class to use when it is necessary to rename a register in class +@var{class} to another class, or perhaps still @var{class}, +if you don't define macro @code{PREFERRED_RENAME_CLASS}. + +Sometimes returning a more restrictive class makes better code. For +example, on ARM, thumb-2 instructions using @code{LOW_REGS} may be +smaller than instructions using @code{GENERIC_REGS}. By returning +@code{LOW_REGS} from @code{PREFERRED_RENAME_CLASS}, code size can +be reduced. +@end deftypefn + @hook TARGET_PREFERRED_RELOAD_CLASS A target hook that places additional restrictions on the register class to use when it is necessary to copy value @var{x} into a register in class diff --git a/gcc/regrename.c b/gcc/regrename.c index 11ae466..6189806 100644 --- a/gcc/regrename.c +++ b/gcc/regrename.c @@ -38,6 +38,7 @@ #include "timevar.h" #include "tree-pass.h" #include "df.h" +#include "target.h" #if HOST_BITS_PER_WIDE_INT <= MAX_RECOG_OPERANDS #error "Use a different bitmap implementation for untracked_operands." @@ -384,12 +385,15 @@ regrename_optimize (void) n_uses = 0; for (tmp = this_head->first; tmp; tmp = tmp->next_use) { + enum reg_class cl; if (DEBUG_INSN_P (tmp->insn)) continue; n_uses++; + cl = (enum reg_class) + targetm.preferred_rename_class(tmp->cl); IOR_COMPL_HARD_REG_SET (this_unavailable, - reg_class_contents[tmp->cl]); + reg_class_contents[cl]); } if (n_uses < 2) diff --git a/gcc/target.def b/gcc/target.def index 82f3040..84c0710 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -2089,6 +2089,12 @@ DEFHOOK bool, (reg_class_t rclass), default_class_likely_spilled_p) +DEFHOOK +(preferred_rename_class, + "", + reg_class_t, (reg_class_t rclass), + default_preferred_rename_class) + /* This target hook allows the backend to perform additional processing while initializing for variable expansion. */ DEFHOOK diff --git a/gcc/targhooks.c b/gcc/targhooks.c index 5948e3f..ea94c87 100644 --- a/gcc/targhooks.c +++ b/gcc/targhooks.c @@ -1256,6 +1256,16 @@ default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED, #endif } +reg_class_t +default_preferred_rename_class (reg_class_t rclass) +{ +#ifdef PREFERRED_RENAME_CLASS + return PREFERRED_RENAME_CLASS ((enum reg_class)rclass); +#else + return rclass; +#endif +} + /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P. */ bool diff --git a/gcc/targhooks.h b/gcc/targhooks.h index 7b640cc..ba3dd17 100644 --- a/gcc/targhooks.h +++ b/gcc/targhooks.h @@ -156,6 +156,7 @@ extern int default_register_move_cost (enum machine_mode, reg_class_t, extern bool default_profile_before_prologue (void); extern reg_class_t default_preferred_reload_class (rtx, reg_class_t); extern reg_class_t default_preferred_output_reload_class (rtx, reg_class_t); +extern reg_class_t default_preferred_rename_class (reg_class_t rclass); extern bool default_class_likely_spilled_p (reg_class_t); extern enum unwind_info_type default_debug_unwind_info (void);