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| author | Richard Kenner <kenner@vlsi1.ultra.nyu.edu> | 1999-03-21 23:44:51 +0000 |
|---|---|---|
| committer | Richard Kenner <kenner@vlsi1.ultra.nyu.edu> | 1999-03-21 23:44:51 +0000 |
| commit | 54a98a3e2bd7c3a66148dbbf01a40377925ccbf2 (patch) | |
| tree | 04083d69c47191ab52a717ea48d03d455d73ae12 | |
| parent | 084aaf75125d41a5b368ab6b6b4b557bced3e84b (diff) | |
(contains_muldiv): New function.
(try_combine): Call it when dividing a PARALLEL.
(simplify_rtx, case TRUNCATE): Don't remove for umulsi3_highpart.
git-svn-id: https://gcc.gnu.org/svn/gcc/branches/premerge-fsf-branch@25887 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/combine.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 31d2814b6cd..fd25ea2bd55 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -392,6 +392,7 @@ static void setup_incoming_promotions PROTO((void)); static void set_nonzero_bits_and_sign_copies PROTO((rtx, rtx)); static int can_combine_p PROTO((rtx, rtx, rtx, rtx, rtx *, rtx *)); static int combinable_i3pat PROTO((rtx, rtx *, rtx, rtx, int, rtx *)); +static int contains_muldiv PROTO((rtx)); static rtx try_combine PROTO((rtx, rtx, rtx)); static void undo_all PROTO((void)); static rtx *find_split_point PROTO((rtx *, rtx)); @@ -1234,6 +1235,36 @@ combinable_i3pat (i3, loc, i2dest, i1dest, i1_not_in_src, pi3dest_killed) return 1; } +/* Return 1 if X is an arithmetic expression that contains a multiplication + and division. We don't count multiplications by powers of two here. */ + +static int +contains_muldiv (x) + rtx x; +{ + switch (GET_CODE (x)) + { + case MOD: case DIV: case UMOD: case UDIV: + return 1; + + case MULT: + return ! (GET_CODE (XEXP (x, 1)) == CONST_INT + && exact_log2 (INTVAL (XEXP (x, 1))) >= 0); + } + + switch (GET_RTX_CLASS (GET_CODE (x))) + { + case 'c': case '<': case '2': + return contains_muldiv (XEXP (x, 0)) || contains_muldiv (XEXP (x, 1)); + + case '1': + return contains_muldiv (XEXP (x, 0)); + + default: + return 0; + } +} + /* Try to combine the insns I1 and I2 into I3. Here I1 and I2 appear earlier than I3. I1 can be zero; then we combine just I2 into I3. @@ -2088,7 +2119,9 @@ try_combine (i3, i2, i1) && ! reg_referenced_p (SET_DEST (XVECEXP (newpat, 0, 1)), XVECEXP (newpat, 0, 0)) && ! reg_referenced_p (SET_DEST (XVECEXP (newpat, 0, 0)), - XVECEXP (newpat, 0, 1))) + XVECEXP (newpat, 0, 1)) + && ! (contains_muldiv (SET_SRC (XVECEXP (newpat, 0, 0))) + && contains_muldiv (SET_SRC (XVECEXP (newpat, 0, 1))))) { /* Normally, it doesn't matter which of the two is done first, but it does if one references cc0. In that case, it has to @@ -3685,9 +3718,13 @@ simplify_rtx (x, op0_mode, last, in_dest) return SUBREG_REG (XEXP (x, 0)); /* If we know that the value is already truncated, we can - replace the TRUNCATE with a SUBREG. */ + replace the TRUNCATE with a SUBREG. But don't do this for + an (LSHIFTRT (MULT ...)) since this will cause problems with + the umulXi3_highpart patterns. */ if (num_sign_bit_copies (XEXP (x, 0), GET_MODE (XEXP (x, 0))) - >= GET_MODE_BITSIZE (mode) + 1) + >= GET_MODE_BITSIZE (mode) + 1 + && ! (GET_CODE (XEXP (x, 0)) == LSHIFTRT + && GET_CODE (XEXP (XEXP (x, 0), 0)) == MULT)) return gen_lowpart_for_combine (mode, XEXP (x, 0)); /* A truncate of a comparison can be replaced with a subreg if |