Re: [PATCH] Unrolling addressing optimization (re-submission)

[Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>]

Hello,

> > 1) why do you check for EXPR_LISTs there?
> 
> Shift instructions include REG_EQUAL notes.
> Those notes are been retrieved just before testing for
> givness or calculating the stride:
> 
> rhs = find_reg_equal_equiv_note (insn);

hmmm... a bug in loop-iv.c.  This patch should fix it; I will send it
for review once it passes neccesary tests.

Zdenek

Index: loop-iv.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/loop-iv.c,v
retrieving revision 2.7
diff -c -3 -p -r2.7 loop-iv.c
*** loop-iv.c	18 Mar 2004 16:42:31 -0000	2.7
--- loop-iv.c	26 Apr 2004 11:55:17 -0000
*************** mark_single_set (rtx insn, rtx set)
*** 254,260 ****
    unsigned regno, uid;
  
    src = find_reg_equal_equiv_note (insn);
!   if (!src)
      src = SET_SRC (set);
  
    if (!simple_set_p (SET_DEST (set), src))
--- 254,262 ----
    unsigned regno, uid;
  
    src = find_reg_equal_equiv_note (insn);
!   if (src)
!     src = XEXP (src, 0);
!   else
      src = SET_SRC (set);
  
    if (!simple_set_p (SET_DEST (set), src))
*************** get_biv_step_1 (rtx insn, rtx reg,
*** 603,609 ****
  
    set = single_set (insn);
    rhs = find_reg_equal_equiv_note (insn);
!   if (!rhs)
      rhs = SET_SRC (set);
    lhs = SET_DEST (set);
  
--- 605,613 ----
  
    set = single_set (insn);
    rhs = find_reg_equal_equiv_note (insn);
!   if (rhs)
!     rhs = XEXP (rhs, 0);
!   else
      rhs = SET_SRC (set);
    lhs = SET_DEST (set);
  
*************** iv_analyze (rtx insn, rtx def, struct rt
*** 979,985 ****
  
    set = single_set (insn);
    rhs = find_reg_equal_equiv_note (insn);
!   if (!rhs)
      rhs = SET_SRC (set);
    code = GET_CODE (rhs);
  
--- 983,991 ----
  
    set = single_set (insn);
    rhs = find_reg_equal_equiv_note (insn);
!   if (rhs)
!     rhs = XEXP (rhs, 0);
!   else
      rhs = SET_SRC (set);
    code = GET_CODE (rhs);
  
*************** simplify_using_assignment (rtx insn, rtx
*** 1337,1343 ****
      return;
  
    rhs = find_reg_equal_equiv_note (insn);
!   if (!rhs)
      rhs = SET_SRC (set);
  
    if (!simple_rhs_p (rhs))
--- 1343,1351 ----
      return;
  
    rhs = find_reg_equal_equiv_note (insn);
!   if (rhs)
!     rhs = XEXP (rhs, 0);
!   else
      rhs = SET_SRC (set);
  
    if (!simple_rhs_p (rhs))