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Re: Two more doloop patches


Zdenek Dvorak wrote:
Hi,

These two patches strengthen functions in loop-iv.c so that we allow frame and stack pointers in the expressions we're examining. For loops that walk an array on the stack, the exit test often is a pointer comparison involving addresses based on fp or sp, and the compiler can make useful simplifications if these substitutions are allowed.

Bootstrapped and regression tested on i686-linux (irrelevant extra failures in libmudflap due to expect truncating compilre output). Equivalent patches have been in our Blackfin 4.3 tree for a while now and had a fair amount of testing.

+      note = find_reg_equal_equiv_note (DF_REF_INSN (adef));
+      if (note && function_invariant_p (XEXP (note, 0)))
+	src = XEXP (note, 0);
+      else
+	src = SET_SRC (set);
+
+      if (REG_P (SET_SRC (set)))
+	{
+	  regno = REGNO (SET_SRC (set));
+	  continue;
+	}
+      break;

maybe


if (note && function_invariant_p (XEXP (note, 0)))
  {
    src = XEXP (note, 0);
    break;
  }
src = SET_SRC (set);

if (REG_P (src))
  ...

?

Otherwise OK,

Changed, retested to make sure that bfin-elf produces identical output, and bootstrapped on i686-linux. Committed.



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