diff options
Diffstat (limited to 'gcc/tree-loop-distribution.c')
| -rw-r--r-- | gcc/tree-loop-distribution.c | 123 |
1 files changed, 122 insertions, 1 deletions
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c index 6abb7e4..52db3c9 100644 --- a/gcc/tree-loop-distribution.c +++ b/gcc/tree-loop-distribution.c @@ -90,6 +90,7 @@ along with GCC; see the file COPYING3. If not see data reuse. */ #include "config.h" +#define INCLUDE_ALGORITHM /* stable_sort */ #include "system.h" #include "coretypes.h" #include "backend.h" @@ -106,6 +107,7 @@ along with GCC; see the file COPYING3. If not see #include "stor-layout.h" #include "tree-cfg.h" #include "tree-ssa-loop-manip.h" +#include "tree-ssa-loop-ivopts.h" #include "tree-ssa-loop.h" #include "tree-into-ssa.h" #include "tree-ssa.h" @@ -604,6 +606,10 @@ struct builtin_info tree dst_base; tree src_base; tree size; + /* Base and offset part of dst_base after stripping constant offset. This + is only used in memset builtin distribution for now. */ + tree dst_base_base; + unsigned HOST_WIDE_INT dst_base_offset; }; /* Partition for loop distribution. */ @@ -1504,7 +1510,11 @@ classify_builtin_st (loop_p loop, partition *partition, data_reference_p dr) if (!compute_access_range (loop, dr, &base, &size)) return; - partition->builtin = alloc_builtin (dr, NULL, base, NULL_TREE, size); + struct builtin_info *builtin; + builtin = alloc_builtin (dr, NULL, base, NULL_TREE, size); + builtin->dst_base_base = strip_offset (builtin->dst_base, + &builtin->dst_base_offset); + partition->builtin = builtin; partition->kind = PKIND_MEMSET; } @@ -2480,6 +2490,113 @@ version_for_distribution_p (vec<struct partition *> *partitions, return (alias_ddrs->length () > 0); } +/* Compare base offset of builtin mem* partitions P1 and P2. */ + +static bool +offset_cmp (struct partition *p1, struct partition *p2) +{ + gcc_assert (p1 != NULL && p1->builtin != NULL); + gcc_assert (p2 != NULL && p2->builtin != NULL); + return p1->builtin->dst_base_offset < p2->builtin->dst_base_offset; +} + +/* Fuse adjacent memset builtin PARTITIONS if possible. This is a special + case optimization transforming below code: + + __builtin_memset (&obj, 0, 100); + _1 = &obj + 100; + __builtin_memset (_1, 0, 200); + _2 = &obj + 300; + __builtin_memset (_2, 0, 100); + + into: + + __builtin_memset (&obj, 0, 400); + + Note we don't have dependence information between different partitions + at this point, as a result, we can't handle nonadjacent memset builtin + partitions since dependence might be broken. */ + +static void +fuse_memset_builtins (vec<struct partition *> *partitions) +{ + unsigned i, j; + struct partition *part1, *part2; + + for (i = 0; partitions->iterate (i, &part1);) + { + if (part1->kind != PKIND_MEMSET) + { + i++; + continue; + } + + /* Find sub-array of memset builtins of the same base. Index range + of the sub-array is [i, j) with "j > i". */ + for (j = i + 1; partitions->iterate (j, &part2); ++j) + { + if (part2->kind != PKIND_MEMSET + || !operand_equal_p (part1->builtin->dst_base_base, + part2->builtin->dst_base_base, 0)) + break; + } + + /* Stable sort is required in order to avoid breaking dependence. */ + std::stable_sort (&(*partitions)[i], + &(*partitions)[i] + j - i, offset_cmp); + /* Continue with next partition. */ + i = j; + } + + /* Merge all consecutive memset builtin partitions. */ + for (i = 0; i < partitions->length () - 1;) + { + part1 = (*partitions)[i]; + if (part1->kind != PKIND_MEMSET) + { + i++; + continue; + } + + part2 = (*partitions)[i + 1]; + /* Only merge memset partitions of the same base and with constant + access sizes. */ + if (part2->kind != PKIND_MEMSET + || TREE_CODE (part1->builtin->size) != INTEGER_CST + || TREE_CODE (part2->builtin->size) != INTEGER_CST + || !operand_equal_p (part1->builtin->dst_base_base, + part2->builtin->dst_base_base, 0)) + { + i++; + continue; + } + tree rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr)); + tree rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr)); + int bytev1 = const_with_all_bytes_same (rhs1); + int bytev2 = const_with_all_bytes_same (rhs2); + /* Only merge memset partitions of the same value. */ + if (bytev1 != bytev2 || bytev1 == -1) + { + i++; + continue; + } + wide_int end1 = wi::add (part1->builtin->dst_base_offset, + wi::to_wide (part1->builtin->size)); + /* Only merge adjacent memset partitions. */ + if (wi::ne_p (end1, part2->builtin->dst_base_offset)) + { + i++; + continue; + } + /* Merge partitions[i] and partitions[i+1]. */ + part1->builtin->size = fold_build2 (PLUS_EXPR, sizetype, + part1->builtin->size, + part2->builtin->size); + partition_free (part2); + partitions->ordered_remove (i + 1); + } +} + /* Fuse PARTITIONS of LOOP if necessary before finalizing distribution. ALIAS_DDRS contains ddrs which need runtime alias check. */ @@ -2523,6 +2640,10 @@ finalize_partitions (struct loop *loop, vec<struct partition *> *partitions, } partitions->truncate (1); } + + /* Fuse memset builtins if possible. */ + if (partitions->length () > 1) + fuse_memset_builtins (partitions); } /* Distributes the code from LOOP in such a way that producer statements |