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| author | Tejas Belagod <tejas.belagod@arm.com> | 2013-12-05 17:24:52 +0000 |
|---|---|---|
| committer | Tejas Belagod <belagod@gcc.gnu.org> | 2013-12-05 17:24:52 +0000 |
| commit | 8c8952918b75f4fa6adbbe44cd641d5fd0bb55e3 (patch) | |
| tree | 9724f5ffff7a15227f05b12519028d421225dfaf /gcc/rtlanal.c | |
| parent | 601a5921eb0b56c647b3fa7136d11172495c0cb0 (diff) | |
| download | gcc-8c8952918b75f4fa6adbbe44cd641d5fd0bb55e3.zip gcc-8c8952918b75f4fa6adbbe44cd641d5fd0bb55e3.tar.gz gcc-8c8952918b75f4fa6adbbe44cd641d5fd0bb55e3.tar.bz2 | |
Eliminate redundant vec_select moves.
gcc/
* rtlanal.c (set_noop_p): Return nonzero in case of redundant vec_select for
overlapping register lanes.
testsuite/
* config/gcc.dg/vect/vect-nop-move.c: New.
From-SVN: r205712
Diffstat (limited to 'gcc/rtlanal.c')
| -rw-r--r-- | gcc/rtlanal.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c index 0cd0c7e..38f9e36 100644 --- a/gcc/rtlanal.c +++ b/gcc/rtlanal.c @@ -1180,6 +1180,27 @@ set_noop_p (const_rtx set) dst = SUBREG_REG (dst); } + /* It is a NOOP if destination overlaps with selected src vector + elements. */ + if (GET_CODE (src) == VEC_SELECT + && REG_P (XEXP (src, 0)) && REG_P (dst) + && HARD_REGISTER_P (XEXP (src, 0)) + && HARD_REGISTER_P (dst)) + { + int i; + rtx par = XEXP (src, 1); + rtx src0 = XEXP (src, 0); + int c0 = INTVAL (XVECEXP (par, 0, 0)); + HOST_WIDE_INT offset = GET_MODE_UNIT_SIZE (GET_MODE (src0)) * c0; + + for (i = 1; i < XVECLEN (par, 0); i++) + if (INTVAL (XVECEXP (par, 0, i)) != c0 + i) + return 0; + return + simplify_subreg_regno (REGNO (src0), GET_MODE (src0), + offset, GET_MODE (dst)) == (int) REGNO (dst); + } + return (REG_P (src) && REG_P (dst) && REGNO (src) == REGNO (dst)); } |