Re: alphaev6-unknown-linux-gnu: error in extract_insn, at recog.c:2127

[Richard Henderson <rth at redhat dot com>]

On Tue, Jul 24, 2001 at 05:40:38PM -0700, Richard Henderson wrote:
> As a workaround, give the following a try.

I should have looked at the actual assembly output closer -- that
patch is incorrect in that it will _never_ match a true zero.  I
forgot about the hidden const_double_chain member of CONST_DOUBLE.


r~



Index: config/alpha/alpha.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/alpha/alpha.c,v
retrieving revision 1.175
diff -c -p -d -r1.175 alpha.c
*** alpha.c	2001/07/22 16:02:06	1.175
--- alpha.c	2001/07/25 00:54:17
*************** mul8_operand (op, mode)
*** 566,579 ****
  }
  
  /* Return 1 if OP is the constant zero in floating-point.  */
  
  int
  fp0_operand (op, mode)
       register rtx op;
       enum machine_mode mode;
  {
!   return (GET_MODE (op) == mode
! 	  && GET_MODE_CLASS (mode) == MODE_FLOAT && op == CONST0_RTX (mode));
  }
  
  /* Return 1 if OP is the floating-point constant zero or a register.  */
--- 566,596 ----
  }
  
  /* Return 1 if OP is the constant zero in floating-point.  */
+ /* ??? Use of CONST0_RTX in nested functions is currently broken.  */
  
  int
  fp0_operand (op, mode)
       register rtx op;
       enum machine_mode mode;
  {
!   int i;
! 
!   if (GET_CODE (op) != CONST_DOUBLE)
!     return 0;
! 
!   if (mode == VOIDmode)
!     {
!       if (GET_MODE_CLASS (GET_MODE (op)) != MODE_FLOAT)
! 	return 0;
!     }
!   else if (GET_MODE (op) != mode)
!     return 0;
! 
!   for (i = GET_RTX_LENGTH (CONST_DOUBLE) - 1; i > 1; --i)
!     if (XWINT (op, i) != 0)
!       return 0;
! 
!   return 1;
  }
  
  /* Return 1 if OP is the floating-point constant zero or a register.  */
*************** input_operand (op, mode)
*** 705,711 ****
  	      && general_operand (op, mode));
  
      case CONST_DOUBLE:
!       return GET_MODE_CLASS (mode) == MODE_FLOAT && op == CONST0_RTX (mode);
  
      case CONST_INT:
        return mode == QImode || mode == HImode || add_operand (op, mode);
--- 722,728 ----
  	      && general_operand (op, mode));
  
      case CONST_DOUBLE:
!       return op == CONST0_RTX (mode) || fp0_operand (op, VOIDmode);
  
      case CONST_INT:
        return mode == QImode || mode == HImode || add_operand (op, mode);
*************** alpha_emit_conditional_branch (code)
*** 1768,1776 ****
  	{
  	  /* When we are not as concerned about non-finite values, and we
  	     are comparing against zero, we can branch directly.  */
! 	  if (op1 == CONST0_RTX (DFmode))
  	    cmp_code = NIL, branch_code = code;
! 	  else if (op0 == CONST0_RTX (DFmode))
  	    {
  	      /* Undo the swap we probably did just above.  */
  	      tem = op0, op0 = op1, op1 = tem;
--- 1785,1793 ----
  	{
  	  /* When we are not as concerned about non-finite values, and we
  	     are comparing against zero, we can branch directly.  */
! 	  if (fp0_operand (op1, DFmode))
  	    cmp_code = NIL, branch_code = code;
! 	  else if (fp0_operand (op0, DFmode))
  	    {
  	      /* Undo the swap we probably did just above.  */
  	      tem = op0, op0 = op1, op1 = tem;
*************** print_operand (file, x, code)
*** 3866,3871 ****
--- 3883,3890 ----
  	fprintf (file, "%s", reg_names[REGNO (x)]);
        else if (x == CONST0_RTX (GET_MODE (x)))
  	fprintf (file, "$31");
+       else if (fp0_operand (x, VOIDmode))
+ 	fprintf (file, "$31");
        else
  	output_operand_lossage ("invalid %%r value");
  
*************** print_operand (file, x, code)
*** 3876,3881 ****
--- 3895,3902 ----
        if (GET_CODE (x) == REG)
  	fprintf (file, "%s", reg_names[REGNO (x)]);
        else if (x == CONST0_RTX (GET_MODE (x)))
+ 	fprintf (file, "$f31");
+       else if (fp0_operand (x, VOIDmode))
  	fprintf (file, "$f31");
        else
  	output_operand_lossage ("invalid %%R value");
Index: config/alpha/alpha.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/alpha/alpha.h,v
retrieving revision 1.126
diff -c -p -d -r1.126 alpha.h
*** alpha.h	2001/07/22 16:02:06	1.126
--- alpha.h	2001/07/25 00:54:18
*************** enum reg_class { NO_REGS, PV_REG, GENERA
*** 766,773 ****
     that is the operand of a ZAP insn.  */
  
  #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C)  			\
!   ((C) == 'G' ? (GET_MODE_CLASS (GET_MODE (VALUE)) == MODE_FLOAT	\
! 		 && (VALUE) == CONST0_RTX (GET_MODE (VALUE)))		\
     : (C) == 'H' ? (GET_MODE (VALUE) == VOIDmode				\
  		   && zap_mask (CONST_DOUBLE_LOW (VALUE))		\
  		   && zap_mask (CONST_DOUBLE_HIGH (VALUE)))		\
--- 766,772 ----
     that is the operand of a ZAP insn.  */
  
  #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C)  			\
!   ((C) == 'G' ? fp0_operand ((VALUE), VOIDmode)				\
     : (C) == 'H' ? (GET_MODE (VALUE) == VOIDmode				\
  		   && zap_mask (CONST_DOUBLE_LOW (VALUE))		\
  		   && zap_mask (CONST_DOUBLE_HIGH (VALUE)))		\