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| author | Richard Kenner <kenner@gcc.gnu.org> | 1992-12-28 06:08:28 -0500 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1992-12-28 06:08:28 -0500 |
| commit | 3bed814135dda6a1aa1171c0719675f1903f346f (patch) | |
| tree | 2450c6894c80409fd357f064632fe9d3bbac57e1 /gcc/combine.c | |
| parent | cbec710efcae143355573a17944f821557fb78af (diff) | |
| download | gcc-3bed814135dda6a1aa1171c0719675f1903f346f.zip gcc-3bed814135dda6a1aa1171c0719675f1903f346f.tar.gz gcc-3bed814135dda6a1aa1171c0719675f1903f346f.tar.bz2 | |
(simplify_comparison, case NEG): Replace large block of code with
equivalent call to num_sign_bit_copies.
From-SVN: r2972
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 25 |
1 files changed, 3 insertions, 22 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index d702d31..90a02cf 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -8029,28 +8029,9 @@ simplify_comparison (code, pop0, pop1) continue; } - /* If we have NEG of something that is the result of a - SIGN_EXTEND, SIGN_EXTRACT, or ASHIFTRT, we know that the - two high-order bits must be the same and hence that - "(-a) < 0" is equivalent to "a > 0". Otherwise, we can't - do this. */ - if (GET_CODE (XEXP (op0, 0)) == SIGN_EXTEND - || (GET_CODE (XEXP (op0, 0)) == SIGN_EXTRACT - && GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT - && (INTVAL (XEXP (XEXP (op0, 0), 1)) - < GET_MODE_BITSIZE (GET_MODE (XEXP (XEXP (op0, 0), 0))))) - || (GET_CODE (XEXP (op0, 0)) == ASHIFTRT - && GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT - && XEXP (XEXP (op0, 0), 1) != const0_rtx) - || ((tem = get_last_value (XEXP (op0, 0))) != 0 - && (GET_CODE (tem) == SIGN_EXTEND - || (GET_CODE (tem) == SIGN_EXTRACT - && GET_CODE (XEXP (tem, 1)) == CONST_INT - && (INTVAL (XEXP (tem, 1)) - < GET_MODE_BITSIZE (GET_MODE (XEXP (tem, 0))))) - || (GET_CODE (tem) == ASHIFTRT - && GET_CODE (XEXP (tem, 1)) == CONST_INT - && XEXP (tem, 1) != const0_rtx)))) + /* If we have NEG of something whose two high-order bits are the + same, we know that "(-a) < 0" is equivalent to "a > 0". */ + if (num_sign_bit_copies (op0, mode) >= 2) { op0 = XEXP (op0, 0); code = swap_condition (code); |