From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 117144 invoked by alias); 7 Jan 2019 08:10:18 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 117102 invoked by uid 89); 7 Jan 2019 08:10:17 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-11.9 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,SPF_PASS autolearn=ham version=3.3.2 spammy=corner, 31AM, 31am X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 07 Jan 2019 08:10:13 +0000 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 377D1ACD7; Mon, 7 Jan 2019 08:10:11 +0000 (UTC) Date: Mon, 07 Jan 2019 08:10:00 -0000 From: Richard Biener To: Jakub Jelinek cc: Jeff Law , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Add a two value VR comparison to two consecutive PHI args optimization (PR tree-optimization/88676, take 2) In-Reply-To: <20190105121747.GF30353@tucnak> Message-ID: References: <20190104224945.GB30353@tucnak> <96DDDCCF-06A3-4D09-A6E6-AD820130A588@suse.de> <20190105121747.GF30353@tucnak> User-Agent: Alpine 2.20 (LSU 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SW-Source: 2019-01/txt/msg00266.txt.bz2 On Sat, 5 Jan 2019, Jakub Jelinek wrote: > On Sat, Jan 05, 2019 at 09:51:31AM +0100, Richard Biener wrote: > > >+ if (TYPE_PRECISION (TREE_TYPE (lhs)) == TYPE_PRECISION (TREE_TYPE > > >(arg0))) > > >+ { > > >+ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE > > >+ || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0))) > > >+ type = TREE_TYPE (lhs); > > >+ else > > >+ type = TREE_TYPE (arg0); > > > > This misses some comments. Presumably you want to avoid arithmetic with bool types (or generally non-mode precision types!?). > > Just for bool because the weird semantics it has. And do as few conversions > as possible. > > > >+ } > > >+ else if (TYPE_PRECISION (TREE_TYPE (lhs)) > TYPE_PRECISION > > >(TREE_TYPE (arg0))) > > >+ type = TREE_TYPE (lhs); > > >+ else > > >+ type = TREE_TYPE (arg0); > > >+ if (!TYPE_OVERFLOW_WRAPS (type)) > > >+ type = unsigned_type_for (type); > > > > Would doing this unconditionally simplify things? I think "optimizing" the - fwrapv case isn't worth it. > > I've originally meant to do it only if really needed but then got lazy. > > > >+ tree m = fold_convert (type, wide_int_to_tree (TREE_TYPE (lhs), > > >min)); > > >+ enum tree_code code; > > >+ if (tree_int_cst_lt (arg0, arg1)) > > >+ { > > >+ code = PLUS_EXPR; > > >+ m = int_const_binop (MINUS_EXPR, fold_convert (type, arg0), m); > > >+ } > > >+ else > > >+ { > > >+ code = MINUS_EXPR; > > >+ m = int_const_binop (PLUS_EXPR, fold_convert (type, arg0), m); > > >+ } > > > > Delay wide-int to tree conversion until here. > > But by doing these computations on wide-int properly it appears it isn't > that hard to do. > > Essentially, after conversion to type, lhs is known to be in [min, min+1] > range and we either want to perform lhs + a or a - lhs. > If it is in signed type, we need to verify it doesn't overflow, so if > a is non-negative, make sure (min+1) + a doesn't overflow and if a > is negative, make sure min + a doesn't overflow. Similarly, for > a - lhs case, if min (and min+1) are non-negative, make sure a - (min+1) > doesn't overflow, and if min is negative (min+1 in that case could be > negative or 0), make sure a - min doesn't overflow. > > Ok for trunk if it passes bootstrap/regtest? OK. Thanks, Richard. > I guess I should add more testcases that test these corner cases, > the boundary cases of overflowing/not overflowing and different precisions > of the two types. > > 2019-01-05 Jakub Jelinek > > PR tree-optimization/88676 > * tree-ssa-phiopt.c (two_value_replacement): New function. > (tree_ssa_phiopt_worker): Call it. > > * gcc.dg/tree-ssa/pr88676.c: New test. > * gcc.dg/pr88676.c: New test. > * gcc.dg/tree-ssa/pr15826.c: Just verify there is no goto, > allow &. > > --- gcc/tree-ssa-phiopt.c.jj 2019-01-04 18:53:11.315322371 +0100 > +++ gcc/tree-ssa-phiopt.c 2019-01-05 13:04:38.185082743 +0100 > @@ -48,6 +48,8 @@ along with GCC; see the file COPYING3. > #include "case-cfn-macros.h" > > static unsigned int tree_ssa_phiopt_worker (bool, bool, bool); > +static bool two_value_replacement (basic_block, basic_block, edge, gphi *, > + tree, tree); > static bool conditional_replacement (basic_block, basic_block, > edge, edge, gphi *, tree, tree); > static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree, > @@ -332,8 +334,11 @@ tree_ssa_phiopt_worker (bool do_store_el > } > > /* Do the replacement of conditional if it can be done. */ > - if (!early_p > - && conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) > + if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) > + cfgchanged = true; > + else if (!early_p > + && conditional_replacement (bb, bb1, e1, e2, phi, > + arg0, arg1)) > cfgchanged = true; > else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) > cfgchanged = true; > @@ -572,6 +577,142 @@ factor_out_conditional_conversion (edge > return newphi; > } > > +/* Optimize > + # x_5 in range [cst1, cst2] where cst2 = cst1 + 1 > + if (x_5 op cstN) # where op is == or != and N is 1 or 2 > + goto bb3; > + else > + goto bb4; > + bb3: > + bb4: > + # r_6 = PHI # where cst3 == cst4 + 1 or cst4 == cst3 + 1 > + > + to r_6 = x_5 + (min (cst3, cst4) - cst1) or > + r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which > + of cst3 and cst4 is smaller. */ > + > +static bool > +two_value_replacement (basic_block cond_bb, basic_block middle_bb, > + edge e1, gphi *phi, tree arg0, tree arg1) > +{ > + /* Only look for adjacent integer constants. */ > + if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0)) > + || !INTEGRAL_TYPE_P (TREE_TYPE (arg1)) > + || TREE_CODE (arg0) != INTEGER_CST > + || TREE_CODE (arg1) != INTEGER_CST > + || (tree_int_cst_lt (arg0, arg1) > + ? wi::to_widest (arg0) + 1 != wi::to_widest (arg1) > + : wi::to_widest (arg1) + 1 != wi::to_widest (arg1))) > + return false; > + > + if (!empty_block_p (middle_bb)) > + return false; > + > + gimple *stmt = last_stmt (cond_bb); > + tree lhs = gimple_cond_lhs (stmt); > + tree rhs = gimple_cond_rhs (stmt); > + > + if (TREE_CODE (lhs) != SSA_NAME > + || !INTEGRAL_TYPE_P (TREE_TYPE (lhs)) > + || TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE > + || TREE_CODE (rhs) != INTEGER_CST) > + return false; > + > + switch (gimple_cond_code (stmt)) > + { > + case EQ_EXPR: > + case NE_EXPR: > + break; > + default: > + return false; > + } > + > + wide_int min, max; > + if (get_range_info (lhs, &min, &max) != VR_RANGE > + || min + 1 != max > + || (wi::to_wide (rhs) != min > + && wi::to_wide (rhs) != max)) > + return false; > + > + /* We need to know which is the true edge and which is the false > + edge so that we know when to invert the condition below. */ > + edge true_edge, false_edge; > + extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); > + if ((gimple_cond_code (stmt) == EQ_EXPR) > + ^ (wi::to_wide (rhs) == max) > + ^ (e1 == false_edge)) > + std::swap (arg0, arg1); > + > + tree type; > + if (TYPE_PRECISION (TREE_TYPE (lhs)) == TYPE_PRECISION (TREE_TYPE (arg0))) > + { > + /* Avoid performing the arithmetics in bool type which has different > + semantics, otherwise prefer unsigned types from the two with > + the same precision. */ > + if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE > + || !TYPE_UNSIGNED (TREE_TYPE (arg0))) > + type = TREE_TYPE (lhs); > + else > + type = TREE_TYPE (arg0); > + } > + else if (TYPE_PRECISION (TREE_TYPE (lhs)) > TYPE_PRECISION (TREE_TYPE (arg0))) > + type = TREE_TYPE (lhs); > + else > + type = TREE_TYPE (arg0); > + > + min = wide_int::from (min, TYPE_PRECISION (type), > + TYPE_SIGN (TREE_TYPE (lhs))); > + wide_int a = wide_int::from (wi::to_wide (arg0), TYPE_PRECISION (type), > + TYPE_SIGN (TREE_TYPE (arg0))); > + enum tree_code code; > + wi::overflow_type ovf; > + if (tree_int_cst_lt (arg0, arg1)) > + { > + code = PLUS_EXPR; > + a -= min; > + if (!TYPE_UNSIGNED (type)) > + { > + /* lhs is known to be in range [min, min+1] and we want to add a > + to it. Check if that operation can overflow for those 2 values > + and if yes, force unsigned type. */ > + wi::add (min + (wi::neg_p (a) ? 0 : 1), a, SIGNED, &ovf); > + if (ovf) > + type = unsigned_type_for (type); > + } > + } > + else > + { > + code = MINUS_EXPR; > + a += min; > + if (!TYPE_UNSIGNED (type)) > + { > + /* lhs is known to be in range [min, min+1] and we want to subtract > + it from a. Check if that operation can overflow for those 2 > + values and if yes, force unsigned type. */ > + wi::sub (a, min + (wi::neg_p (min) ? 0 : 1), SIGNED, &ovf); > + if (ovf) > + type = unsigned_type_for (type); > + } > + } > + > + tree arg = wide_int_to_tree (type, a); > + gimple_stmt_iterator gsi = gsi_for_stmt (stmt); > + if (!useless_type_conversion_p (type, TREE_TYPE (lhs))) > + lhs = gimplify_build1 (&gsi, NOP_EXPR, type, lhs); > + tree new_rhs; > + if (code == PLUS_EXPR) > + new_rhs = gimplify_build2 (&gsi, PLUS_EXPR, type, lhs, arg); > + else > + new_rhs = gimplify_build2 (&gsi, MINUS_EXPR, type, arg, lhs); > + if (!useless_type_conversion_p (TREE_TYPE (arg0), type)) > + new_rhs = gimplify_build1 (&gsi, NOP_EXPR, TREE_TYPE (arg0), new_rhs); > + > + replace_phi_edge_with_variable (cond_bb, e1, phi, new_rhs); > + > + /* Note that we optimized this PHI. */ > + return true; > +} > + > /* The function conditional_replacement does the main work of doing the > conditional replacement. Return true if the replacement is done. > Otherwise return false. > --- gcc/testsuite/gcc.dg/tree-ssa/pr88676.c.jj 2019-01-05 12:25:32.463958539 +0100 > +++ gcc/testsuite/gcc.dg/tree-ssa/pr88676.c 2019-01-05 12:25:32.463958539 +0100 > @@ -0,0 +1,133 @@ > +/* PR tree-optimization/88676 */ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-optimized" } */ > +/* { dg-final { scan-tree-dump-not " = PHI <" "optimized" } } */ > + > +void bar (int, int, int); > + > +__attribute__((noipa)) int > +f1 (unsigned x) > +{ > + int r; > + if (x >= 2) > + __builtin_unreachable (); > + switch (x) > + { > + case 0: > + r = 1; > + break; > + case 1: > + r = 2; > + break; > + default: > + r = 0; > + break; > + } > + return r; > +} > + > +__attribute__((noipa)) void > +f2 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x != 98) > + y = 115; > + else > + y = 116; > + bar (x, y, 116); > +} > + > +__attribute__((noipa)) void > +f3 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x == 98) > + y = 115; > + else > + y = 116; > + bar (x, y, 115); > +} > + > +__attribute__((noipa)) void > +f4 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x != 99) > + y = 115; > + else > + y = 116; > + bar (x, y, 115); > +} > + > +__attribute__((noipa)) void > +f5 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x == 99) > + y = 115; > + else > + y = 116; > + bar (x, y, 116); > +} > + > +__attribute__((noipa)) void > +f6 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x != 98) > + y = 116; > + else > + y = 115; > + bar (x, y, 115); > +} > + > +__attribute__((noipa)) void > +f7 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x == 98) > + y = 116; > + else > + y = 115; > + bar (x, y, 116); > +} > + > +__attribute__((noipa)) void > +f8 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x != 99) > + y = 116; > + else > + y = 115; > + bar (x, y, 116); > +} > + > +__attribute__((noipa)) void > +f9 (int x) > +{ > + int y; > + x = (x & 1) + 98; > + if (x == 99) > + y = 116; > + else > + y = 115; > + bar (x, y, 115); > +} > + > +__attribute__((noipa)) int > +f10 (int x) > +{ > + x = (x & 1) + 36; > + if (x == 36) > + return 85; > + else > + return 84; > +} > --- gcc/testsuite/gcc.dg/pr88676.c.jj 2019-01-05 12:25:32.463958539 +0100 > +++ gcc/testsuite/gcc.dg/pr88676.c 2019-01-05 12:25:32.463958539 +0100 > @@ -0,0 +1,48 @@ > +/* PR tree-optimization/88676 */ > +/* { dg-do run } */ > +/* { dg-options "-O2" } */ > + > +#include "tree-ssa/pr88676.c" > + > +__attribute__((noipa)) void > +bar (int x, int y, int z) > +{ > + if (z != 115 && z != 116) > + __builtin_abort (); > + if (x == 98) > + { > + if (y != z) > + __builtin_abort (); > + } > + else if (x != 99) > + __builtin_abort (); > + else if (z == 115) > + { > + if (y != 116) > + __builtin_abort (); > + } > + else if (y != 115) > + __builtin_abort (); > +} > + > +int > +main () > +{ > + if (f1 (0) != 1 || f1 (1) != 2) > + __builtin_abort (); > + int i; > + for (i = -12; i < 12; i++) > + { > + f2 (i); > + f3 (i); > + f4 (i); > + f5 (i); > + f6 (i); > + f7 (i); > + f8 (i); > + f9 (i); > + if (f10 (i) != ((i & 1) ? 84 : 85)) > + __builtin_abort (); > + } > + return 0; > +} > --- gcc/testsuite/gcc.dg/tree-ssa/pr15826.c.jj 2016-02-27 07:41:54.377920386 +0100 > +++ gcc/testsuite/gcc.dg/tree-ssa/pr15826.c 2019-01-05 12:25:32.463958539 +0100 > @@ -33,4 +33,4 @@ andrew (struct s *p) > return i; > } > > -/* { dg-final { scan-tree-dump-times " & | goto " 0 "optimized" } } */ > +/* { dg-final { scan-tree-dump-not "goto " "optimized" } } */ > > > Jakub > > -- Richard Biener SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)