diff options
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 76fbe1b..1021391 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -4632,8 +4632,8 @@ make_extraction (mode, inner, pos, pos_rtx, len, a SUBREG and it would sometimes return a new hard register. */ new = gen_rtx (SUBREG, tmode, inner, (WORDS_BIG_ENDIAN - && GET_MODE_SIZE (is_mode) > UNITS_PER_WORD - ? ((GET_MODE_SIZE (is_mode) - GET_MODE_SIZE (tmode)) + && GET_MODE_SIZE (inner_mode) > UNITS_PER_WORD + ? ((GET_MODE_SIZE (inner_mode) - GET_MODE_SIZE (tmode)) / UNITS_PER_WORD) : 0)); else @@ -6345,7 +6345,12 @@ num_sign_bit_copies (x, mode) be such a carry. Furthermore, if the positive number is known to be 0 or 1, we know the result is either -1 or 0. */ - if (code == PLUS && XEXP (x, 1) == constm1_rtx) + if (code == PLUS && XEXP (x, 1) == constm1_rtx + /* Don't do this if XEXP (x, 0) is a paradoxical subreg + because in principle we don't know what the high bits are. */ + && !(GET_CODE (XEXP (x, 0)) == SUBREG + && (GET_MODE_SIZE (GET_MODE (XEXP (XEXP (x, 0), 0))) + < GET_MODE_SIZE (GET_MODE (XEXP (x, 0)))))) { sig = significant_bits (XEXP (x, 0), mode); if ((((HOST_WIDE_INT) 1 << (bitwidth - 1)) & sig) == 0) |