On Fri, Sep 30, 2011 at 02:26:40PM +0200, Richard Guenther wrote:
> > It is boolean only in some testcases, the is_bool stuff discussed at the
> > beginning above was originally just an early return
> >  if (TREE_CODE (TREE_TYPE (exp)) != BOOLEAN_TYPE)
> >    return;
> > before the loop, but it turned out that often the type of the | operands
> > is integer, with either bool casted to integer, or with the type of EQ_EXPR
> > etc. being integer instead of bool.
> 
> Really?  The type of EQ_EXPR should be always either BOOLEAN_TYPE
> or INTEGRAL_TYPE_P with TYPE_PRECISION == 1.  That's what
> the gimple verifier checks.  Or do you mean that fold introduces these
> kind of types during range-test simplification?

Consider:

int
f1 (int a, int b)
{
  int v1 = (a <= 64);
  int v2 = (a == 66);
  int v3 = (a == 67);
  int v4 = (a == 65);
  return b || v1 || v2 || v3 || v4;
}

int
f2 (int a, int b)
{
  int v1 = (a <= 64);
  int v2 = (a == 66);
  int v3 = (a == 67);
  int v4 = (a == 65);
  return b | v1 | v2 | v3 | v4;
}

in *.dse1 f1 is:
  D.2744_2 = a_1(D) <= 64;
  v1_3 = (int) D.2744_2;
  D.2745_4 = a_1(D) == 66;
  v2_5 = (int) D.2745_4;
  D.2746_6 = a_1(D) == 67;
  v3_7 = (int) D.2746_6;
  D.2747_8 = a_1(D) == 65;
  v4_9 = (int) D.2747_8;
  D.2749_11 = b_10(D) | v1_3;
  D.2750_12 = D.2749_11 | v2_5;
  D.2751_13 = D.2750_12 | v3_7;
  D.2752_14 = D.2751_13 | v4_9;
  D.2753_15 = D.2752_14 != 0;
  D.2748_16 = (int) D.2753_15;
  return D.2748_16;
and f2 is:
  D.2735_2 = a_1(D) <= 64;
  v1_3 = (int) D.2735_2;
  D.2736_4 = a_1(D) == 66;
  v2_5 = (int) D.2736_4;
  D.2737_6 = a_1(D) == 67;
  v3_7 = (int) D.2737_6;
  D.2738_8 = a_1(D) == 65;
  v4_9 = (int) D.2738_8;
  D.2740_11 = b_10(D) | v1_3;
  D.2741_12 = D.2740_11 | v2_5;
  D.2742_13 = D.2741_12 | v3_7;
  D.2739_14 = D.2742_13 | v4_9;
  return D.2739_14;
In both cases, the arguments of BIT_IOR_EXPR are ints
and init_range_entry needs to go through the casts to reach the
comparison (on which it figures out that the value is really 0/1,
well, in this case already on the rhs of the cast, as it is _Bool).

        Jakub

Reply via email to