From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28746 invoked by alias); 26 Mar 2012 23:57:54 -0000 Received: (qmail 28737 invoked by uid 22791); 26 Mar 2012 23:57:51 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from qmta04.emeryville.ca.mail.comcast.net (HELO qmta04.emeryville.ca.mail.comcast.net) (76.96.30.40) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 26 Mar 2012 23:57:31 +0000 Received: from omta12.emeryville.ca.mail.comcast.net ([76.96.30.44]) by qmta04.emeryville.ca.mail.comcast.net with comcast id qPwX1i0010x6nqcA4PxXvB; Mon, 26 Mar 2012 23:57:31 +0000 Received: from up.mrs.kithrup.com ([24.4.193.8]) by omta12.emeryville.ca.mail.comcast.net with comcast id qPxW1i0090BKwT48YPxWVC; Mon, 26 Mar 2012 23:57:31 +0000 Subject: Re: remove wrong code in immed_double_const Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/mixed; boundary=Apple-Mail-6-164248156 From: Mike Stump In-Reply-To: <87haxb6ses.fsf@talisman.home> Date: Mon, 26 Mar 2012 23:57:00 -0000 Cc: gcc-patches Patches , Richard Sandiford Message-Id: References: <5FF5A724-3FE1-4E97-8124-542A0B8259FE@comcast.net> <87obrvd6fh.fsf@talisman.home> <87haxmgqoo.fsf@talisman.home> <7C6A7462-C1D3-4765-83FF-3B3C726D92E5@comcast.net> <8762e09sgc.fsf@talisman.home> <0A5CBD0C-FC94-4637-B230-1A83372DE91A@comcast.net> <83448720-93D1-483D-8B8C-08B672399E1B@comcast.net> <87mx7763g5.fsf@talisman.home> <87haxb6ses.fsf@talisman.home> To: Richard Guenther X-IsSubscribed: yes 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 X-SW-Source: 2012-03/txt/msg01693.txt.bz2 --Apple-Mail-6-164248156 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-length: 728 On Mar 26, 2012, at 1:03 PM, Richard Sandiford wrote: > I think: > > ...copies of the top bit. Note however that values are neither inherently > signed nor inherently unsigned; where necessary, signedness is determined > by the rtl operation instead. Sounds good to me, changed. > Same idea here. Fixed. >> +/* Return an rtx for the sum of X and the integer C, given that X has >> + mode MODE. This routine should be used instead of plus_constant >> + when they want to ensure that addition happens in a particular >> + mode, which is necessary when x can be a VOIDmode CONST_INT or > > Sorry, just noticed, should be "...when X can be..." Fixed. Richard has ok all his bits, now down to you for final ok. Ok? --Apple-Mail-6-164248156 Content-Disposition: attachment; filename=oi-trunk-2.diffs.txt Content-Type: text/plain; name="oi-trunk-2.diffs.txt" Content-Transfer-Encoding: quoted-printable Content-length: 14760 * doc/rtl.texi (const_double): Document as sign-extending. * expmed.c (expand_mult): Ensure we don't use shift incorrectly. * emit-rtl.c (immed_double_int_const): Refine to state the value is signed. * simplify-rtx.c (mode_signbit_p): Add a fixme for wider than CONST_DOUBLE integers. (simplify_const_unary_operation, UNSIGNED_FLOAT): Ensure no negative values are converted. Fix conversions bigger than HOST_BITS_PER_WIDE_INT. (simplify_binary_operation_1): Ensure we don't use shift incorrectly. (simplify_immed_subreg): Sign-extend CONST_DOUBLEs. * explow.c (plus_constant_mode): Add. (plus_constant): Implement with plus_constant_mode. * rtl.h (plus_constant_mode): Add. Index: doc/rtl.texi =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- doc/rtl.texi (revision 185706) +++ doc/rtl.texi (working copy) @@ -1479,8 +1479,19 @@ This type of expression represents the i is customarily accessed with the macro @code{INTVAL} as in @code{INTVAL (@var{exp})}, which is equivalent to @code{XWINT (@var{exp}, = 0)}. =20 -Constants generated for modes with fewer bits than @code{HOST_WIDE_INT} -must be sign extended to full width (e.g., with @code{gen_int_mode}). +Constants generated for modes with fewer bits than in +@code{HOST_WIDE_INT} must be sign extended to full width (e.g., with +@code{gen_int_mode}). For constants for modes with more bits than in +@code{HOST_WIDE_INT} the implied high order bits of that constant are +copies of the top bit. Note however that values are neither +inherently signed nor inherently unsigned; where necessary, signedness +is determined by the rtl operation instead. + + +, however values are neither signed nor unsigned. +All operations defined on such constants define the signededness. + + =20 @findex const0_rtx @findex const1_rtx @@ -1510,7 +1521,13 @@ Represents either a floating-point const integer constant too large to fit into @code{HOST_BITS_PER_WIDE_INT} bits but small enough to fit within twice that number of bits (GCC does not provide a mechanism to represent even larger constants). In -the latter case, @var{m} will be @code{VOIDmode}. +the latter case, @var{m} will be @code{VOIDmode}. For integral values +constants for modes with more bits than twice the number in +@code{HOST_WIDE_INT} the implied high order bits of that constant are +copies of the top bit of @code{CONST_DOUBLE_HIGH}. Note however that +integral values are neither inherently signed nor inherently unsigned; +where necessary, signedness is determined by the rtl operation +instead. =20 @findex CONST_DOUBLE_LOW If @var{m} is @code{VOIDmode}, the bits of the value are stored in Index: expmed.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- expmed.c (revision 185706) +++ expmed.c (working copy) @@ -3135,8 +3135,10 @@ expand_mult (enum machine_mode mode, rtx { int shift =3D floor_log2 (CONST_DOUBLE_HIGH (op1)) + HOST_BITS_PER_WIDE_INT; - return expand_shift (LSHIFT_EXPR, mode, op0, - shift, target, unsignedp); + if (shift < 2 * HOST_BITS_PER_WIDE_INT - 1 + || GET_MODE_BITSIZE (mode) <=3D 2 * HOST_BITS_PER_WIDE_INT) + return expand_shift (LSHIFT_EXPR, mode, op0, + shift, target, unsignedp); } } =20 Index: emit-rtl.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- emit-rtl.c (revision 185706) +++ emit-rtl.c (working copy) @@ -517,8 +517,11 @@ immed_double_int_const (double_int i, en =20 /* Return a CONST_DOUBLE or CONST_INT for a value specified as a pair of ints: I0 is the low-order word and I1 is the high-order word. - Do not use this routine for non-integer modes; convert to - REAL_VALUE_TYPE and use CONST_DOUBLE_FROM_REAL_VALUE. */ + For values that are larger than 2*HOST_BITS_PER_WIDE_INT, the + implied upper bits are copies of the high bit of i1. The value + itself is neither signed nor unsigned. Do not use this routine for + non-integer modes; convert to REAL_VALUE_TYPE and use + CONST_DOUBLE_FROM_REAL_VALUE. */ =20 rtx immed_double_const (HOST_WIDE_INT i0, HOST_WIDE_INT i1, enum machine_mode = mode) @@ -531,10 +534,9 @@ immed_double_const (HOST_WIDE_INT i0, HO =20 1) If GET_MODE_BITSIZE (mode) <=3D HOST_BITS_PER_WIDE_INT, then we use gen_int_mode. - 2) GET_MODE_BITSIZE (mode) =3D=3D 2 * HOST_BITS_PER_WIDE_INT, but the= value of - the integer fits into HOST_WIDE_INT anyway (i.e., i1 consists only - from copies of the sign bit, and sign of i0 and i1 are the same), then - we return a CONST_INT for i0. + 2) If the value of the integer fits into HOST_WIDE_INT anyway + (i.e., i1 consists only from copies of the sign bit, and sign + of i0 and i1 are the same), then we return a CONST_INT for i0. 3) Otherwise, we create a CONST_DOUBLE for i0 and i1. */ if (mode !=3D VOIDmode) { @@ -546,8 +548,6 @@ immed_double_const (HOST_WIDE_INT i0, HO =20 if (GET_MODE_BITSIZE (mode) <=3D HOST_BITS_PER_WIDE_INT) return gen_int_mode (i0, mode); - - gcc_assert (GET_MODE_BITSIZE (mode) =3D=3D 2 * HOST_BITS_PER_WIDE_IN= T); } =20 /* If this integer fits in one word, return a CONST_INT. */ Index: simplify-rtx.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- simplify-rtx.c (revision 185706) +++ simplify-rtx.c (working copy) @@ -97,6 +97,7 @@ mode_signbit_p (enum machine_mode mode,=20 width -=3D HOST_BITS_PER_WIDE_INT; } else + /* FIXME: We don't yet have a representation for wider modes. */ return false; =20 if (width < HOST_BITS_PER_WIDE_INT) @@ -1355,16 +1356,11 @@ simplify_const_unary_operation (enum rtx else lv =3D CONST_DOUBLE_LOW (op), hv =3D CONST_DOUBLE_HIGH (op); =20 - if (op_mode =3D=3D VOIDmode) - { - /* We don't know how to interpret negative-looking numbers in - this case, so don't try to fold those. */ - if (hv < 0) - return 0; - } - else if (GET_MODE_PRECISION (op_mode) >=3D HOST_BITS_PER_WIDE_INT * = 2) - ; - else + if (op_mode =3D=3D VOIDmode + || GET_MODE_PRECISION (op_mode) > 2 * HOST_BITS_PER_WIDE_INT) + /* We should never get a negative number. */ + gcc_assert (hv >=3D 0); + else if (GET_MODE_PRECISION (op_mode) <=3D HOST_BITS_PER_WIDE_INT) hv =3D 0, lv &=3D GET_MODE_MASK (op_mode); =20 REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode); @@ -1718,7 +1714,7 @@ simplify_const_unary_operation (enum rtx else if (GET_CODE (op) =3D=3D CONST_DOUBLE && SCALAR_FLOAT_MODE_P (GET_MODE (op)) && GET_MODE_CLASS (mode) =3D=3D MODE_INT - && width <=3D 2*HOST_BITS_PER_WIDE_INT && width > 0) + && width <=3D 2 * HOST_BITS_PER_WIDE_INT && width > 0) { /* Although the overflow semantics of RTL's FIX and UNSIGNED_FIX operators are intentionally left unspecified (to ease implementation @@ -1783,7 +1779,7 @@ simplify_const_unary_operation (enum rtx return const0_rtx; =20 /* Test against the unsigned upper bound. */ - if (width =3D=3D 2*HOST_BITS_PER_WIDE_INT) + if (width =3D=3D 2 * HOST_BITS_PER_WIDE_INT) { th =3D -1; tl =3D -1; @@ -2380,7 +2376,9 @@ simplify_binary_operation_1 (enum rtx_co || GET_MODE_CLASS (GET_MODE (trueop1)) =3D=3D MODE_INT) && GET_MODE (op0) =3D=3D mode && CONST_DOUBLE_LOW (trueop1) =3D=3D 0 - && (val =3D exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >=3D 0) + && (val =3D exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >=3D 0 + && (val < 2 * HOST_BITS_PER_WIDE_INT - 1 + || GET_MODE_BITSIZE (mode) <=3D 2 * HOST_BITS_PER_WIDE_INT)) return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val + HOST_BITS_PER_WIDE_INT)); =20 @@ -5189,6 +5187,7 @@ simplify_immed_subreg (enum machine_mode case CONST_DOUBLE: if (GET_MODE (el) =3D=3D VOIDmode) { + unsigned char extend =3D 0; /* If this triggers, someone should have generated a CONST_INT instead. */ gcc_assert (elem_bitsize > HOST_BITS_PER_WIDE_INT); @@ -5201,10 +5200,11 @@ simplify_immed_subreg (enum machine_mode =3D CONST_DOUBLE_HIGH (el) >> (i - HOST_BITS_PER_WIDE_INT); i +=3D value_bit; } - /* It shouldn't matter what's done here, so fill it with - zero. */ + + if (CONST_DOUBLE_HIGH (el) >> (HOST_BITS_PER_WIDE_INT - 1)) + extend =3D -1; for (; i < elem_bitsize; i +=3D value_bit) - *vp++ =3D 0; + *vp++ =3D extend; } else { Index: explow.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- explow.c (revision 185706) +++ explow.c (working copy) @@ -74,14 +74,20 @@ trunc_int_for_mode (HOST_WIDE_INT c, enu return c; } =20 -/* Return an rtx for the sum of X and the integer C. */ +/* Return an rtx for the sum of X and the integer C, given that X has + mode MODE. This routine should be used instead of plus_constant + when they want to ensure that addition happens in a particular + mode, which is necessary when X can be a VOIDmode CONST_INT or + CONST_DOUBLE and the width of the constant is different from the + width of the expression. */ +/* TODO: All callers of plus_constant should migrate to this routine, + and once they do, we can assert that mode is not VOIDmode. */ =20 rtx -plus_constant (rtx x, HOST_WIDE_INT c) +plus_constant_mode (enum machine_mode mode, rtx x, HOST_WIDE_INT c) { RTX_CODE code; rtx y; - enum machine_mode mode; rtx tem; int all_constant =3D 0; =20 @@ -91,12 +97,26 @@ plus_constant (rtx x, HOST_WIDE_INT c) restart: =20 code =3D GET_CODE (x); - mode =3D GET_MODE (x); y =3D x; =20 switch (code) { case CONST_INT: + if (GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT) + { + unsigned HOST_WIDE_INT l1 =3D INTVAL (x); + HOST_WIDE_INT h1 =3D (l1 >> (HOST_BITS_PER_WIDE_INT - 1)) ? -1 : 0; + unsigned HOST_WIDE_INT l2 =3D c; + HOST_WIDE_INT h2 =3D c < 0 ? -1 : 0; + unsigned HOST_WIDE_INT lv; + HOST_WIDE_INT hv; + + if (add_double_with_sign (l1, h1, l2, h2, &lv, &hv, false)) + gcc_unreachable (); + + return immed_double_const (lv, hv, VOIDmode); + } + return GEN_INT (INTVAL (x) + c); =20 case CONST_DOUBLE: @@ -104,11 +124,14 @@ plus_constant (rtx x, HOST_WIDE_INT c) unsigned HOST_WIDE_INT l1 =3D CONST_DOUBLE_LOW (x); HOST_WIDE_INT h1 =3D CONST_DOUBLE_HIGH (x); unsigned HOST_WIDE_INT l2 =3D c; - HOST_WIDE_INT h2 =3D c < 0 ? ~0 : 0; + HOST_WIDE_INT h2 =3D c < 0 ? -1 : 0; unsigned HOST_WIDE_INT lv; HOST_WIDE_INT hv; =20 - add_double (l1, h1, l2, h2, &lv, &hv); + if (add_double_with_sign (l1, h1, l2, h2, &lv, &hv, false)) + /* Sorry, we have no way to represent overflows this wide. + To fix, add constant support wider than CONST_DOUBLE. */ + gcc_assert (GET_MODE_BITSIZE (mode) <=3D 2 * HOST_BITS_PER_WIDE_INT); =20 return immed_double_const (lv, hv, VOIDmode); } @@ -120,10 +143,8 @@ plus_constant (rtx x, HOST_WIDE_INT c) if (GET_CODE (XEXP (x, 0)) =3D=3D SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) { - tem - =3D force_const_mem (GET_MODE (x), - plus_constant (get_pool_constant (XEXP (x, 0)), - c)); + tem =3D plus_constant_mode (mode, get_pool_constant (XEXP (x, 0)), c); + tem =3D force_const_mem (GET_MODE (x), tem); if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) return tem; } @@ -142,31 +163,17 @@ plus_constant (rtx x, HOST_WIDE_INT c) break; =20 case PLUS: - /* The interesting case is adding the integer to a sum. - Look for constant term in the sum and combine - with C. For an integer constant term, we make a combined - integer. For a constant term that is not an explicit integer, - we cannot really combine, but group them together anyway. - - Restart or use a recursive call in case the remaining operand is - something that we handle specially, such as a SYMBOL_REF. + /* The interesting case is adding the integer to a sum. Look + for constant term in the sum and combine with C. For an + integer constant term or a constant term that is not an + explicit integer, we combine or group them together anyway. =20 We may not immediately return from the recursive call here, lest all_constant gets lost. */ =20 - if (CONST_INT_P (XEXP (x, 1))) + if (CONSTANT_P (XEXP (x, 1))) { - c +=3D INTVAL (XEXP (x, 1)); - - if (GET_MODE (x) !=3D VOIDmode) - c =3D trunc_int_for_mode (c, GET_MODE (x)); - - x =3D XEXP (x, 0); - goto restart; - } - else if (CONSTANT_P (XEXP (x, 1))) - { - x =3D gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c)); + x =3D gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant_mode (mode, XEXP (= x, 1), c)); c =3D 0; } else if (find_constant_term_loc (&y)) @@ -176,7 +183,7 @@ plus_constant (rtx x, HOST_WIDE_INT c) rtx copy =3D copy_rtx (x); rtx *const_loc =3D find_constant_term_loc (©); =20 - *const_loc =3D plus_constant (*const_loc, c); + *const_loc =3D plus_constant_mode (mode, *const_loc, c); x =3D copy; c =3D 0; } @@ -196,6 +203,14 @@ plus_constant (rtx x, HOST_WIDE_INT c) else return x; } + +/* Return an rtx for the sum of X and the integer C. */ + +rtx +plus_constant (rtx x, HOST_WIDE_INT c) +{ + return plus_constant_mode (GET_MODE (x), x, c); +} =0C /* If X is a sum, return a new sum like X but lacking any constant terms. Add all the removed constant terms into *CONSTPTR. Index: rtl.h =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- rtl.h (revision 185706) +++ rtl.h (working copy) @@ -1644,6 +1644,7 @@ extern int ceil_log2 (unsigned HOST_WIDE /* In explow.c */ extern HOST_WIDE_INT trunc_int_for_mode (HOST_WIDE_INT, enum machine_mode); extern rtx plus_constant (rtx, HOST_WIDE_INT); +extern rtx plus_constant_mode (enum machine_mode, rtx, HOST_WIDE_INT); =20 /* In rtl.c */ extern rtx rtx_alloc_stat (RTX_CODE MEM_STAT_DECL); --Apple-Mail-6-164248156--