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| author | Richard Stallman <rms@gnu.org> | 1993-05-28 05:59:04 +0000 |
|---|---|---|
| committer | Richard Stallman <rms@gnu.org> | 1993-05-28 05:59:04 +0000 |
| commit | 6e498949dba764fa067f14f5d03b763bebda905d (patch) | |
| tree | d51f801287ff5928153279f9e43dda8fcbe81fc7 | |
| parent | 53f269222aeae2ecaa14965463dbb7ab040add5e (diff) | |
| download | gcc-6e498949dba764fa067f14f5d03b763bebda905d.zip gcc-6e498949dba764fa067f14f5d03b763bebda905d.tar.gz gcc-6e498949dba764fa067f14f5d03b763bebda905d.tar.bz2 | |
(simplify_and_const_int, case IOR, XOR, NOT): Don't
create constant wider than mode of VAROP.
From-SVN: r4583
| -rw-r--r-- | gcc/combine.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index b254d36..7a93f2b 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -5968,13 +5968,18 @@ simplify_and_const_int (x, mode, varop, constop) case XOR: /* If VAROP is (ior (lshiftrt FOO C1) C2), try to commute the IOR and LSHIFT so we end up with an (and (lshiftrt (ior ...) ...) ...) - operation which may be a bitfield extraction. */ + operation which may be a bitfield extraction. Ensure + that the constant we form is not wider than the mode of + VAROP. */ if (GET_CODE (XEXP (varop, 0)) == LSHIFTRT && GET_CODE (XEXP (XEXP (varop, 0), 1)) == CONST_INT && INTVAL (XEXP (XEXP (varop, 0), 1)) >= 0 && INTVAL (XEXP (XEXP (varop, 0), 1)) < HOST_BITS_PER_WIDE_INT && GET_CODE (XEXP (varop, 1)) == CONST_INT + && ((INTVAL (XEXP (XEXP (varop, 0), 1)) + + floor_log2 (INTVAL (XEXP (varop, 1)))) + < GET_MODE_BITSIZE (GET_MODE (varop))) && (INTVAL (XEXP (varop, 1)) & ~ nonzero_bits (XEXP (varop, 0), GET_MODE (varop)) == 0)) { @@ -6003,12 +6008,15 @@ simplify_and_const_int (x, mode, varop, constop) XEXP (varop, 1), constop)))); case NOT: - /* (and (not FOO)) is (and (xor FOO CONST_OP)) so if FOO is an - LSHIFTRT we can do the same as above. */ + /* (and (not FOO)) is (and (xor FOO CONST)), so if FOO is an + LSHIFTRT, we can do the same as above. Ensure that the constant + we form is not wider than the mode of VAROP. */ if (GET_CODE (XEXP (varop, 0)) == LSHIFTRT && GET_CODE (XEXP (XEXP (varop, 0), 1)) == CONST_INT && INTVAL (XEXP (XEXP (varop, 0), 1)) >= 0 + && (INTVAL (XEXP (XEXP (varop, 0), 1)) + floor_log2 (constop) + < GET_MODE_BITSIZE (GET_MODE (varop))) && INTVAL (XEXP (XEXP (varop, 0), 1)) < HOST_BITS_PER_WIDE_INT) { temp = GEN_INT (constop << INTVAL (XEXP (XEXP (varop, 0), 1))); |