irange on value_range implementation.

Known failures:

*** FAIL: gcc.dg/pr85598.c (test for excess errors)

    x_10 has a global range of [0, 256]
    x_10 = PHI <0(2), x_6(3)> is analyzed as [0, 255][257, 257]
    range_of_stmt calculates the intersection of both:
        range = [0, 255]

    On irange : value_range, the PHI range is [0, 257], so the
    intersection comes out as [0, 256].  This extra number causes
    sprintf to think we'll overflow.

    This is because the sprintf pass has been converted to the
    ranger.  Presumably we can leave sprintf unconverted until we
    have more sub-ranges.

*** FAIL: gcc.dg/tree-ssa/rvrp09.c scan-tree-dump-times rvrp "Branch rewritten" 4

    The branch from BB9 -> BB10 below was previously removed as
    UNDEFINED, but we no longer know d_5 is UNDEFINED on that path
    because of the loss of precision in the original range for
    d_5.

    Note: fails for irange m_max_pairs=2 also.

    Was:

    =========== BB 8 ============
    x_2(D)  char VARYING
        <bb 8> :
        d_5 = x_2(D) & -16;
        if (d_5 > 0)
          goto <bb 9>; [INV]
        else
          goto <bb 11>; [INV]

    d_5 : char [-INF, -16][0, 0][16, 112]
    8->9  (T) d_5 :         char [16, 112]
    8->11  (F) d_5 :        char [-INF, -16][0, 0]

    =========== BB 9 ============
    d_5     char [16, 112]
        <bb 9> :
        if (d_5 <= 15)
          goto <bb 10>; [INV]
        else
          goto <bb 11>; [INV]

===>    9->10  (T) d_5 :        char UNDEFINED
    9->11  (F) d_5 :        char [16, 112]

But is now:

    =========== BB 8 ============
    x_2(D)  char VARYING
        <bb 8> :
        d_5 = x_2(D) & -16;
        if (d_5 > 0)
          goto <bb 9>; [INV]
        else
          goto <bb 11>; [INV]

    d_5 : char [-INF, 112]
    8->9  (T) d_5 :         char [1, 112]
    8->11  (F) d_5 :        char [-INF, 0]

    =========== BB 9 ============
    d_5     char [1, 112]
        <bb 9> :
        if (d_5 <= 15)
          goto <bb 10>; [INV]
        else
          goto <bb 11>; [INV]

===>    9->10  (T) d_5 :        char [1, 15]
    9->11  (F) d_5 :        char [16, 112]

From-SVN: r272458

0 files changed, 0 insertions, 0 deletions