re PR tree-optimization/63266 (Test regression: gcc.target/sh/pr53568-1.c)

re PR tree-optimization/63266 (Test regression: gcc.target/sh/pr53568-1.c)

2014-09-24  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/63266
    * tree-ssa-math-opts.c (struct symbolic_number): Add comment about
    marker for unknown byte value.
    (MARKER_MASK): New macro.
    (MARKER_BYTE_UNKNOWN): New macro.
    (HEAD_MARKER): New macro.
    (do_shift_rotate): Mark bytes with unknown values due to sign
    extension when doing an arithmetic right shift. Replace hardcoded
    mask for marker by new MARKER_MASK macro.
    (find_bswap_or_nop_1): Likewise and adjust ORing of two symbolic
    numbers accordingly.

    gcc/testsuite/
    PR tree-optimization/63266
    * gcc.dg/optimize-bswapsi-1.c (swap32_d): New bswap pass test.

From-SVN: r215546