diff options
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 911ebbf..4bcaf38 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -6935,10 +6935,17 @@ force_to_mode (x, mode, mask, reg, just_select) if (GET_CODE (x) == LSHIFTRT && GET_CODE (XEXP (x, 1)) == CONST_INT + /* The shift puts one of the sign bit copies in the least significant + bit. */ && ((INTVAL (XEXP (x, 1)) + num_sign_bit_copies (XEXP (x, 0), GET_MODE (XEXP (x, 0)))) >= GET_MODE_BITSIZE (GET_MODE (x))) && exact_log2 (mask + 1) >= 0 + /* Number of bits left after the shift must be more than the mask + needs. */ + && ((INTVAL (XEXP (x, 1)) + exact_log2 (mask + 1)) + <= GET_MODE_BITSIZE (GET_MODE (x))) + /* Must be more sign bit copies than the mask needs. */ && ((int) num_sign_bit_copies (XEXP (x, 0), GET_MODE (XEXP (x, 0))) >= exact_log2 (mask + 1))) x = gen_binary (LSHIFTRT, GET_MODE (x), XEXP (x, 0), |