diff options
Diffstat (limited to 'gcc/recog.c')
| -rw-r--r-- | gcc/recog.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/gcc/recog.c b/gcc/recog.c index b8b532e2403..c01f884ebb4 100644 --- a/gcc/recog.c +++ b/gcc/recog.c @@ -480,14 +480,29 @@ validate_replace_rtx_1 (loc, from, to, object) /* In these cases, the operation to be performed depends on the mode of the operand. If we are replacing the operand with a VOIDmode constant, we lose the information. So try to simplify the operation - in that case. If it fails, substitute in something that we know - won't be recognized. */ + in that case. */ if (GET_MODE (to) == VOIDmode - && rtx_equal_p (XEXP (x, 0), from)) + && (rtx_equal_p (XEXP (x, 0), from) + || (GET_CODE (XEXP (x, 0)) == SUBREG + && rtx_equal_p (SUBREG_REG (XEXP (x, 0)), from)))) { - rtx new = simplify_unary_operation (code, GET_MODE (x), to, - GET_MODE (from)); - if (new == 0) + rtx new = NULL_RTX; + + /* If there is a subreg involved, crop to the portion of the + constant that we are interested in. */ + if (GET_CODE (XEXP (x, 0)) == SUBREG) + to = operand_subword (to, SUBREG_WORD (XEXP (x, 0)), + 0, GET_MODE (from)); + + /* If the above didn't fail, perform the extension from the + mode of the operand (and not the mode of FROM). */ + if (to) + new = simplify_unary_operation (code, GET_MODE (x), to, + GET_MODE (XEXP (x, 0))); + + /* If any of the above failed, substitute in something that + we know won't be recognized. */ + if (!new) new = gen_rtx_CLOBBER (GET_MODE (x), const0_rtx); validate_change (object, loc, new, 1); |