Re: RFC: Jump to const_int

[Richard Henderson <rth at redhat dot com>]

On Sun, Jan 14, 2001 at 01:05:42AM -0800, Richard Henderson wrote:
> Indeed this is a problem.  One solution is to modify computed_jump_p
> so that it recognizes this.  I'll probably do that.

Like so.

Bootstrapped on alphaev6, not that that means much as this
sort of failure didn't show up there.


r~


        * rtlanal.c (computed_jump_p_1): Rename from jmp_uses_reg_or_mem;
        update all call sites.  Return true for all non-label constants.

Index: rtlanal.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/rtlanal.c,v
retrieving revision 1.80
diff -c -p -d -r1.80 rtlanal.c
*** rtlanal.c	2001/01/07 13:06:43	1.80
--- rtlanal.c	2001/01/14 10:16:17
*************** static void set_of_1		PARAMS ((rtx, rtx,
*** 29,35 ****
  static void insn_dependent_p_1	PARAMS ((rtx, rtx, void *));
  
  /* Forward declarations */
! static int jmp_uses_reg_or_mem		PARAMS ((rtx));
  
  /* Bit flags that specify the machine subtype we are compiling for.
     Bits are tested using macros TARGET_... defined in the tm.h file
--- 29,35 ----
  static void insn_dependent_p_1	PARAMS ((rtx, rtx, void *));
  
  /* Forward declarations */
! static int computed_jump_p_1	PARAMS ((rtx));
  
  /* Bit flags that specify the machine subtype we are compiling for.
     Bits are tested using macros TARGET_... defined in the tm.h file
*************** replace_regs (x, reg_map, nregs, replace
*** 2181,2191 ****
    return x;
  }
  
! /* Return 1 if X, the SRC_SRC of  SET of (pc) contain a REG or MEM that is
!    not in the constant pool and not in the condition of an IF_THEN_ELSE.  */
  
  static int
! jmp_uses_reg_or_mem (x)
       rtx x;
  {
    enum rtx_code code = GET_CODE (x);
--- 2181,2192 ----
    return x;
  }
  
! /* A subroutine of computed_jump_p, return 1 if X contains a REG or MEM or
!    constant that is not in the constant pool and not in the condition
!    of an IF_THEN_ELSE.  */
  
  static int
! computed_jump_p_1 (x)
       rtx x;
  {
    enum rtx_code code = GET_CODE (x);
*************** jmp_uses_reg_or_mem (x)
*** 2194,2204 ****
  
    switch (code)
      {
-     case CONST:
      case LABEL_REF:
      case PC:
        return 0;
  
      case REG:
        return 1;
  
--- 2195,2208 ----
  
    switch (code)
      {
      case LABEL_REF:
      case PC:
        return 0;
  
+     case CONST:
+     case CONST_INT:
+     case CONST_DOUBLE:
+     case SYMBOL_REF:
      case REG:
        return 1;
  
*************** jmp_uses_reg_or_mem (x)
*** 2207,2218 ****
  		&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)));
  
      case IF_THEN_ELSE:
!       return (jmp_uses_reg_or_mem (XEXP (x, 1))
! 	      || jmp_uses_reg_or_mem (XEXP (x, 2)));
! 
!     case PLUS:  case MINUS:  case MULT:
!       return (jmp_uses_reg_or_mem (XEXP (x, 0))
! 	      || jmp_uses_reg_or_mem (XEXP (x, 1)));
  
      default:
        break;
--- 2211,2218 ----
  		&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)));
  
      case IF_THEN_ELSE:
!       return (computed_jump_p_1 (XEXP (x, 1))
! 	      || computed_jump_p_1 (XEXP (x, 2)));
  
      default:
        break;
*************** jmp_uses_reg_or_mem (x)
*** 2222,2233 ****
    for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
      {
        if (fmt[i] == 'e'
! 	  && jmp_uses_reg_or_mem (XEXP (x, i)))
  	return 1;
  
        else if (fmt[i] == 'E')
  	for (j = 0; j < XVECLEN (x, i); j++)
! 	  if (jmp_uses_reg_or_mem (XVECEXP (x, i, j)))
  	    return 1;
      }
  
--- 2222,2233 ----
    for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
      {
        if (fmt[i] == 'e'
! 	  && computed_jump_p_1 (XEXP (x, i)))
  	return 1;
  
        else if (fmt[i] == 'E')
  	for (j = 0; j < XVECLEN (x, i); j++)
! 	  if (computed_jump_p_1 (XVECEXP (x, i, j)))
  	    return 1;
      }
  
*************** computed_jump_p (insn)
*** 2265,2276 ****
  	    for (i = len - 1; i >= 0; i--)
  	      if (GET_CODE (XVECEXP (pat, 0, i)) == SET
  		  && SET_DEST (XVECEXP (pat, 0, i)) == pc_rtx
! 		  && jmp_uses_reg_or_mem (SET_SRC (XVECEXP (pat, 0, i))))
  		return 1;
  	}
        else if (GET_CODE (pat) == SET
  	       && SET_DEST (pat) == pc_rtx
! 	       && jmp_uses_reg_or_mem (SET_SRC (pat)))
  	return 1;
      }
    return 0;
--- 2265,2276 ----
  	    for (i = len - 1; i >= 0; i--)
  	      if (GET_CODE (XVECEXP (pat, 0, i)) == SET
  		  && SET_DEST (XVECEXP (pat, 0, i)) == pc_rtx
! 		  && computed_jump_p_1 (SET_SRC (XVECEXP (pat, 0, i))))
  		return 1;
  	}
        else if (GET_CODE (pat) == SET
  	       && SET_DEST (pat) == pc_rtx
! 	       && computed_jump_p_1 (SET_SRC (pat)))
  	return 1;
      }
    return 0;