diff options
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index cdc6043..63961dd 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -2271,19 +2271,57 @@ simplify_subreg (outermode, op, innermode, byte) /* Simplify subregs of vector constants. */ if (GET_CODE (op) == CONST_VECTOR) { - int offset = byte / UNITS_PER_WORD; + int elt_size = GET_MODE_SIZE (GET_MODE_INNER (innermode)); + int offset = byte / elt_size; rtx elt; - /* This shouldn't happen, but let's not do anything stupid. */ - if (GET_MODE_INNER (innermode) != outermode) - return NULL_RTX; - - elt = CONST_VECTOR_ELT (op, offset); + if (GET_MODE_INNER (innermode) == outermode) + { + elt = CONST_VECTOR_ELT (op, offset); - /* ?? We probably don't need this copy_rtx because constants - can be shared. ?? */ + /* ?? We probably don't need this copy_rtx because constants + can be shared. ?? */ - return copy_rtx (elt); + return copy_rtx (elt); + } + else if (GET_MODE_INNER (innermode) == GET_MODE_INNER (outermode) + && GET_MODE_SIZE (innermode) > GET_MODE_SIZE (outermode)) + { + return (gen_rtx_CONST_VECTOR + (outermode, + gen_rtvec_v (GET_MODE_NUNITS (outermode), + &CONST_VECTOR_ELT (op, offset)))); + } + else if (GET_MODE_CLASS (outermode) == MODE_INT + && (GET_MODE_SIZE (outermode) % elt_size == 0)) + { + /* This happens when the target register size is smaller then + the vector mode, and we synthesize operations with vectors + of elements that are smaller than the register size. */ + HOST_WIDE_INT sum = 0, high = 0; + unsigned n_elts = (GET_MODE_SIZE (outermode) / elt_size); + unsigned i = BYTES_BIG_ENDIAN ? offset : offset + n_elts - 1; + unsigned step = BYTES_BIG_ENDIAN ? 1 : -1; + int shift = BITS_PER_UNIT * elt_size; + + for (; n_elts--; i += step) + { + elt = CONST_VECTOR_ELT (op, i); + if (GET_CODE (elt) != CONST_INT) + return NULL_RTX; + high = high << shift | sum >> (HOST_BITS_PER_WIDE_INT - shift); + sum = (sum << shift) + INTVAL (elt); + } + if (GET_MODE_BITSIZE (outermode) <= HOST_BITS_PER_WIDE_INT) + return GEN_INT (trunc_int_for_mode (sum, outermode)); + else if (GET_MODE_BITSIZE (outermode) == 2* HOST_BITS_PER_WIDE_INT) + return immed_double_const (high, sum, outermode); + else + return NULL_RTX; + } + else + /* This shouldn't happen, but let's not do anything stupid. */ + return NULL_RTX; } /* Attempt to simplify constant to non-SUBREG expression. */ |