Date: Fri, 06 Feb 2004 12:35:58 +0900

 From: SUGIOKA Toshinobu <sugioka@itonet.co.jp>

 Subject: [linux-sh:03150] Re: gcc 3.3 optimisation problem

 To: linux-sh@m17n.org

 Message-Id: <4.2.0.58.J.20040206122503.04fe3058@router.itonet.co.jp>

 List-Help: <mailto:linux-sh-ctl@m17n.org?body=help>

 List-Id: linux-sh.m17n.org

 At 19:40 03/12/01 +0000, Stuart Menefy <stuart.menefy@st.com> wrote:

 >On Sat, 29 Nov 2003 20:19:08 +0900 kkojima@rr.iij4u.or.jp wrote:

 >

 >> Dan Kegel <dank@kegel.com> wrote:

 >> > Stuart Menefy wrote:

 >> >> I've just been trying to put together a gcc 3.3.2 based toolchain, and

 >> >> appear to be hitting a gcc optimisation bug. I was just wondering if

 >> >> anyone else had seen anything similar.

 >> >> 

 >> >> The problem is seen when building the kernel, in the function

 >> >> root_nfs_parse_addr(). I've extracted this into a small stand alone

 >> >> program which demonstrates the problem.

 >> > 

 >> > Excellent work.  I haven't seen anything like this (doesn't mean much)

 >> > and the sh-specific optimization bugs in the gcc bug database don't look

 >> > similar.  I think you should submit this as a bug report at

 >> > http://gcc.gnu.org/bugzilla/

 >> > It would be good if you could make your test case call abort() if

 >> > the problem is present, so the test case can be automated.

 >> 

 >> Indeed.  It'd be very nice to create a gcc PR for this issue.

 >

 >OK, I've done that. PR 13260.

 PR 13260 was fixed by amylaar@gcc.gnu.org at 2003-12-04 20:10:29 on mainline(gcc-3.4).

 I have back-ported that patch to gcc-3.3.3 and seems fine for me.

 	* sh-protos.h (sh_expand_t_scc): Declare.

 	* sh.h (PREDICATE_CODES): Add cmpsi_operand.

 	* sh.c (cmpsi_operand, sh_expand_t_scc): New functions.

 	* sh.md (cmpsi): Use cmpsi_operand.  If T_REG is compared to

 	something that is not a CONST_INT, copy it into a pseudo register.

 	(subc): Fix description of new T value.

 	(slt, sgt, sge, sgtu): Don't clobber T after rtl generation is over.

 	(sltu, sleu, sgeu): Likewise.

 	(seq, sne): Likewise. Use sh_expand_t_scc.

 diff -ru gcc-3.3-20040126-1/gcc/config/sh/sh-protos.h gcc-3.3-20040126/gcc/config/sh/sh-protos.h

 --- gcc-3.3-20040126-1/gcc/config/sh/sh-protos.h	Tue Jan 13 02:03:24 2004

 +++ gcc-3.3-20040126/gcc/config/sh/sh-protos.h	Fri Jan 30 17:54:04 2004

 @@ -102,6 +102,7 @@

  extern int sh_can_redirect_branch PARAMS ((rtx, rtx));

  extern void sh_expand_unop_v2sf PARAMS ((enum rtx_code, rtx, rtx));

  extern void sh_expand_binop_v2sf PARAMS ((enum rtx_code, rtx, rtx, rtx));

 +extern int sh_expand_t_scc (enum rtx_code code, rtx target);

  #ifdef TREE_CODE

  extern void sh_va_start PARAMS ((tree, rtx));

  extern rtx sh_va_arg PARAMS ((tree, tree));

 diff -ru gcc-3.3-20040126-1/gcc/config/sh/sh.c gcc-3.3-20040126/gcc/config/sh/sh.c

 --- gcc-3.3-20040126-1/gcc/config/sh/sh.c	Thu Jan 15 03:11:36 2004

 +++ gcc-3.3-20040126/gcc/config/sh/sh.c	Fri Jan 30 17:53:58 2004

 @@ -7870,6 +7870,15 @@

    return register_operand (op, mode);

  }

 +int

 +cmpsi_operand (rtx op, enum machine_mode mode)

 +{

 +  if (GET_CODE (op) == REG && REGNO (op) == T_REG

 +      && GET_MODE (op) == SImode)

 +    return 1;

 +  return arith_operand (op, mode);

 +}

 +

  /* INSN is an sfunc; return the rtx that describes the address used.  */

  static rtx

  extract_sfunc_addr (rtx insn)

 @@ -7917,4 +7926,33 @@

    abort ();

  }

 +int

 +sh_expand_t_scc (enum rtx_code code, rtx target)

 +{

 +  rtx result = target;

 +  HOST_WIDE_INT val;

 +

 +  if (GET_CODE (sh_compare_op0) != REG || REGNO (sh_compare_op0) != T_REG

 +      || GET_CODE (sh_compare_op1) != CONST_INT)

 +    return 0;

 +  if (GET_CODE (result) != REG)

 +    result = gen_reg_rtx (SImode);

 +  val = INTVAL (sh_compare_op1);

 +  if ((code == EQ && val == 1) || (code == NE && val == 0))

 +    emit_insn (gen_movt (result));

 +  else if ((code == EQ && val == 0) || (code == NE && val == 1))

 +    {

 +      emit_insn (gen_rtx_CLOBBER (VOIDmode, result));

 +      emit_insn (gen_subc (result, result, result));

 +      emit_insn (gen_addsi3 (result, result, GEN_INT (1)));

 +    }

 +  else if (code == EQ || code == NE)

 +    emit_insn (gen_move_insn (result, GEN_INT (code == NE)));

 +  else

 +    return 0;

 +  if (result != target)

 +    emit_move_insn (target, result);

 +  return 1;

 +}

 +

  #include "gt-sh.h"

 diff -ru gcc-3.3-20040126-1/gcc/config/sh/sh.h gcc-3.3-20040126/gcc/config/sh/sh.h

 --- gcc-3.3-20040126-1/gcc/config/sh/sh.h	Wed Apr 16 02:06:09 2003

 +++ gcc-3.3-20040126/gcc/config/sh/sh.h	Fri Jan 30 17:53:51 2004

 @@ -3231,6 +3231,7 @@

    {"arith_reg_or_0_operand", {SUBREG, REG, CONST_INT, CONST_VECTOR}},	\

    {"binary_float_operator", {PLUS, MINUS, MULT, DIV}},			\

    {"binary_logical_operator", {AND, IOR, XOR}},				\

 +  {"cmpsi_operand", {SUBREG, REG, CONST_INT}},				\

    {"commutative_float_operator", {PLUS, MULT}},				\

    {"equality_comparison_operator", {EQ,NE}},				\

    {"extend_reg_operand", {SUBREG, REG, TRUNCATE}},			\

 diff -ru gcc-3.3-20040126-1/gcc/config/sh/sh.md gcc-3.3-20040126/gcc/config/sh/sh.md

 --- gcc-3.3-20040126-1/gcc/config/sh/sh.md	Tue Jan 13 02:03:25 2004

 +++ gcc-3.3-20040126/gcc/config/sh/sh.md	Fri Jan 30 17:54:20 2004

 @@ -685,11 +685,14 @@

  (define_expand "cmpsi"

    [(set (reg:SI T_REG)

 -	(compare (match_operand:SI 0 "arith_operand" "")

 +	(compare (match_operand:SI 0 "cmpsi_operand" "")

  		 (match_operand:SI 1 "arith_operand" "")))]

    "TARGET_SH1"

    "

  {

 +  if (GET_CODE (operands[0]) == REG && REGNO (operands[0]) == T_REG

 +      && GET_CODE (operands[1]) != CONST_INT)

 +    operands[0] = copy_to_mode_reg (SImode, operands[0]);

    sh_compare_op0 = operands[0];

    sh_compare_op1 = operands[1];

    DONE;

 @@ -1147,7 +1150,9 @@

  			    (match_operand:SI 2 "arith_reg_operand" "r"))

  		  (reg:SI T_REG)))

     (set (reg:SI T_REG)

 -	(gtu:SI (minus:SI (match_dup 1) (match_dup 2)) (match_dup 1)))]

 +	(gtu:SI (minus:SI (minus:SI (match_dup 1) (match_dup 2))

 +			  (reg:SI T_REG))

 +		(match_dup 1)))]

    "TARGET_SH1"

    "subc	%2,%0"

    [(set_attr "type" "arith")])

 @@ -7223,6 +7228,10 @@

  	}

        DONE;

      }

 +  if (sh_expand_t_scc (EQ, operands[0]))

 +    DONE;

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (EQ);

  }")

 @@ -7269,6 +7278,8 @@

  	}

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (LT);

  }")

 @@ -7371,6 +7382,8 @@

  	}

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (GT);

  }")

 @@ -7423,6 +7436,8 @@

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    if (GET_MODE_CLASS (GET_MODE (sh_compare_op0)) == MODE_FLOAT)

      {

        if (TARGET_IEEE)

 @@ -7462,6 +7477,8 @@

  				     sh_compare_op0, sh_compare_op1));

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (GTU);

  }")

 @@ -7486,6 +7503,8 @@

  				     sh_compare_op1, sh_compare_op0));

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (LTU);

  }")

 @@ -7515,6 +7534,8 @@

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (LEU);

  }")

 @@ -7545,6 +7566,8 @@

        DONE;

      }

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

    operands[1] = prepare_scc_operands (GEU);

  }")

 @@ -7592,8 +7615,12 @@

        DONE;

      }

 -   operands[1] = prepare_scc_operands (EQ);

 -   operands[2] = gen_reg_rtx (SImode);

 +  if (sh_expand_t_scc (NE, operands[0]))

 +    DONE;

 +  if (! rtx_equal_function_value_matters)

 +    FAIL;

 +  operands[1] = prepare_scc_operands (EQ);

 +  operands[2] = gen_reg_rtx (SImode);

  }")

  (define_expand "sunordered"

 ----

 SUGIOKA Toshinobu