From 734914b6e230b78eb6c34fbd5a2d93b1a919d36a Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Thu, 7 Dec 2017 18:40:28 +0000 Subject: New VECTOR_CST layout This patch uses a simple compression scheme to represent the contents of a VECTOR_CST using its leading elements. There are three formats: 1) a repeating sequence of N values. This is encoded using the first N elements. 2) a "foreground" sequence of N values inserted at the beginning of a "background" repeating sequence of N values, such as: { 1, 2, 0, 0, 0, 0, ... }. This is encoded using the first 2*N elements. 2) a "foreground" sequence of N values inserted at the beginning of a "background" repeating sequence of N interleaved linear series, such as: { 0, 0, 8, 10, 9, 11, 10, 12, ... }. This is encoded using the first 3*N elements. In practice the foreground values are often part of the same series as the background values, such as: { 1, 11, 2, 12, 3, 13, ... }. This reduces the amount of work involved in processing simple vector constants and means that the encoding extends naturally to variable-length vectors. 2017-12-07 Richard Sandiford gcc/ * doc/generic.texi (VECTOR_CST): Describe new representation of vector constants. * vector-builder.h: New file. * tree-vector-builder.h: Likewise. * tree-vector-builder.c: Likewise. * Makefile.in (OBJS): Add tree-vector-builder.o. * tree.def (VECTOR_CST): Update comment to refer to generic.texi. * tree-core.h (tree_base): Add a vector_cst field to the u union. (tree_vector): Change the number of elements to vector_cst_encoded_nelts. * tree.h (VECTOR_CST_NELTS): Redefine using TYPE_VECTOR_SUBPARTS. (VECTOR_CST_ELTS): Delete. (VECTOR_CST_ELT): Redefine using vector_cst_elt. (VECTOR_CST_LOG2_NPATTERNS, VECTOR_CST_NPATTERNS): New macros. (VECTOR_CST_NELTS_PER_PATTERN, VECTOR_CST_DUPLICATE_P): Likewise. (VECTOR_CST_STEPPED_P, VECTOR_CST_ENCODED_ELTS): Likewise. (VECTOR_CST_ENCODED_ELT): Likewise. (vector_cst_encoded_nelts): New function. (make_vector): Take the values of VECTOR_CST_LOG2_NPATTERNS and VECTOR_CST_NELTS_PER_PATTERN as arguments. (vector_cst_int_elt, vector_cst_elt): Declare. * tree.c: Include tree-vector-builder.h. (tree_code_size): Abort if passed VECTOR_CST. (tree_size): Update for new VECTOR_CST layout. (make_vector): Take the values of VECTOR_CST_LOG2_NPATTERNS and VECTOR_CST_NELTS_PER_PATTERN as arguments. (build_vector): Use tree_vector_builder. (vector_cst_int_elt, vector_cst_elt): New functions. (drop_tree_overflow): For VECTOR_CST, drop the TREE_OVERFLOW from the encoded elements and then create the vector in the canonical form. (check_vector_cst, check_vector_cst_duplicate, check_vector_cst_fill) (check_vector_cst_stepped, test_vector_cst_patterns): New functions. (tree_c_tests): Call test_vector_cst_patterns. * lto-streamer-out.c (DFS::DFS_write_tree_body): Handle the new VECTOR_CST fields. (hash_tree): Likewise. * tree-streamer-out.c (write_ts_vector_tree_pointers): Likewise. (streamer_write_tree_header): Likewise. * tree-streamer-in.c (lto_input_ts_vector_tree_pointers): Likewise. (streamer_alloc_tree): Likewise. Update call to make_vector. * fold-const.c (fold_ternary_loc): Avoid using VECTOR_CST_ELTS. gcc/lto/ * lto.c (compare_tree_sccs_1): Compare the new VECTOR_CST flags. From-SVN: r255474 --- gcc/lto-streamer-out.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'gcc/lto-streamer-out.c') diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c index 0442ec7..4efa9c9 100644 --- a/gcc/lto-streamer-out.c +++ b/gcc/lto-streamer-out.c @@ -747,8 +747,9 @@ DFS::DFS_write_tree_body (struct output_block *ob, if (CODE_CONTAINS_STRUCT (code, TS_VECTOR)) { - for (unsigned i = 0; i < VECTOR_CST_NELTS (expr); ++i) - DFS_follow_tree_edge (VECTOR_CST_ELT (expr, i)); + unsigned int count = vector_cst_encoded_nelts (expr); + for (unsigned int i = 0; i < count; ++i) + DFS_follow_tree_edge (VECTOR_CST_ENCODED_ELT (expr, i)); } if (CODE_CONTAINS_STRUCT (code, TS_COMPLEX)) @@ -1195,8 +1196,11 @@ hash_tree (struct streamer_tree_cache_d *cache, hash_map *map, } if (CODE_CONTAINS_STRUCT (code, TS_VECTOR)) - for (unsigned i = 0; i < VECTOR_CST_NELTS (t); ++i) - visit (VECTOR_CST_ELT (t, i)); + { + unsigned int count = vector_cst_encoded_nelts (t); + for (unsigned int i = 0; i < count; ++i) + visit (VECTOR_CST_ENCODED_ELT (t, i)); + } if (CODE_CONTAINS_STRUCT (code, TS_COMPLEX)) { -- cgit v1.1