On Tue, Nov 11, 2014 at 3:21 PM, Evgeny Stupachenko <evstu...@gmail.com> wrote:
> Hi,
>
> The patch extends shift permutations technique on power of 2 cases
> (previously even/odd transformations was used unconditionally).
> Basically the patch just add loop for load group of length 2, like it
> is done in "vect_permute_load_chain" function.
>
> For Silvermont it reduces insn sequence for load group of length 4
> from 31 to 20 insns.
> Performance for the test in the patch improved by ~20%.
>
> Bootstrap passed.
> Make check in progress.
>
> Is it ok?
Ok.
Thanks,
Richard.
> 2014-11-11 Evgeny Stupachenko <evstu...@gmail.com>
>
> gcc/testsuite
> * gcc.target/i386/pr52252-atom-1.c: New.
>
> gcc/
> * tree-vect-data-refs.c (vect_shift_permute_load_chain): Extend shift
> permutations on power of 2 cases.
>
> diff --git a/gcc/testsuite/gcc.target/i386/pr52252-atom-1.c
> b/gcc/testsuite/gcc.target/i386/pr52252-atom-1.c
> new file mode 100644
> index 0000000..1fbd258
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr52252-atom-1.c
> @@ -0,0 +1,22 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target ssse3 } */
> +/* { dg-options "-O2 -ftree-vectorize -mssse3 -mtune=slm" } */
> +#define byte unsigned char
> +
> +void
> +pair_mul_sum(byte *in, byte *out, int size)
> +{
> + int j;
> + for(j = 0; j < size; j++)
> + {
> + byte a = in[0];
> + byte b = in[1];
> + byte c = in[2];
> + byte d = in[3];
> + out[0] = (byte)(a * b) + (byte)(b * c) + (byte)(c * d) + (byte)(d * a);
> + in += 4;
> + out += 1;
> + }
> +}
> +
> +/* { dg-final { scan-assembler "palignr" } } */
> diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
> index 0bc0356..d2e0e93 100644
> --- a/gcc/tree-vect-data-refs.c
> +++ b/gcc/tree-vect-data-refs.c
> @@ -5379,8 +5379,9 @@ vect_shift_permute_load_chain (vec<tree> dr_chain,
> memcpy (result_chain->address (), dr_chain.address (),
> length * sizeof (tree));
>
> - if (length == 2 && LOOP_VINFO_VECT_FACTOR (loop_vinfo) > 4)
> + if (exact_log2 (length) != -1 && LOOP_VINFO_VECT_FACTOR (loop_vinfo) > 4)
> {
> + unsigned int j, log_length = exact_log2 (length);
> for (i = 0; i < nelt / 2; ++i)
> sel[i] = i * 2;
> for (i = 0; i < nelt / 2; ++i)
> @@ -5441,37 +5442,44 @@ vect_shift_permute_load_chain (vec<tree> dr_chain,
> select_mask = vect_gen_perm_mask (vectype, sel);
> gcc_assert (select_mask != NULL);
>
> - first_vect = dr_chain[0];
> - second_vect = dr_chain[1];
> -
> - data_ref = make_temp_ssa_name (vectype, NULL, "vect_shuffle2");
> - perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR, data_ref,
> - first_vect, first_vect,
> - perm2_mask1);
> - vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> - vect[0] = data_ref;
> + for (i = 0; i < log_length; i++)
> + {
> + for (j = 0; j < length; j += 2)
> + {
> + first_vect = dr_chain[j];
> + second_vect = dr_chain[j + 1];
>
> - data_ref = make_temp_ssa_name (vectype, NULL, "vect_shuffle2");
> - perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR, data_ref,
> - second_vect, second_vect,
> - perm2_mask2);
> - vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> - vect[1] = data_ref;
> + data_ref = make_temp_ssa_name (vectype, NULL, "vect_shuffle2");
> + perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR,
> data_ref,
> + first_vect,
> first_vect,
> + perm2_mask1);
> + vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> + vect[0] = data_ref;
>
> - data_ref = make_temp_ssa_name (vectype, NULL, "vect_shift");
> - perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR, data_ref,
> - vect[0], vect[1],
> - shift1_mask);
> - vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> - (*result_chain)[1] = data_ref;
> + data_ref = make_temp_ssa_name (vectype, NULL, "vect_shuffle2");
> + perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR,
> data_ref,
> + second_vect,
> second_vect,
> + perm2_mask2);
> + vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> + vect[1] = data_ref;
>
> - data_ref = make_temp_ssa_name (vectype, NULL, "vect_select");
> - perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR, data_ref,
> - vect[0], vect[1],
> - select_mask);
> - vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> - (*result_chain)[0] = data_ref;
> + data_ref = make_temp_ssa_name (vectype, NULL, "vect_shift");
> + perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR,
> data_ref,
> + vect[0], vect[1],
> + shift1_mask);
> + vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> + (*result_chain)[j/2 + length/2] = data_ref;
>
> + data_ref = make_temp_ssa_name (vectype, NULL, "vect_select");
> + perm_stmt = gimple_build_assign_with_ops (VEC_PERM_EXPR,
> data_ref,
> + vect[0], vect[1],
> + select_mask);
> + vect_finish_stmt_generation (stmt, perm_stmt, gsi);
> + (*result_chain)[j/2] = data_ref;
> + }
> + memcpy (dr_chain.address (), result_chain->address (),
> + length * sizeof (tree));
> + }
> return true;
> }
> if (length == 3 && LOOP_VINFO_VECT_FACTOR (loop_vinfo) > 2)
