Hi! As the testcases show, dr_explicit_realign_optimized (used on PowerPC/SPU only) misbehaves if the base_address is in between 1 and vector element size - 1 modulo vector size. The problem is that it wants to add a bias to base_addr such that base_addr & ~vector_size (base_addr + bias) & ~vector_size are adjacent vector_size memory slots, but vect_create_data_ref_ptr takes offset counted in vector elements and in the end multiplies that by vector element size, so we end up actually with: (base_addr + ((vector_size / vector_element_size) * vector_element_size) & ~vector_size which unfortunately is not enough, e.g. in the testcase base_addr is 1 moduo vector_size, vector_size 16 and vector_element_size 2, so we have base_addr & ~16 (base_addr + 14) & ~16 instead of the desired (base_addr + 15) & ~16 and 1 & ~16 and (1 + 14) & ~16 is the same address.
Fixed by passing another offset, measured in bytes (for the negative case which are the only 3 other cases which pass any offset down we want it to be as is), bootstrapped/regtested on x86_64-linux and i686-linux and on {x86_64,i686,powerpc{,64},s390{,x}}-linux on the 4.8 branch. Ok for trunk/4.9/4.8? 2014-09-25 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/63341 * tree-vectorizer.h (vect_create_data_ref_ptr, vect_create_addr_base_for_vector_ref): Add another tree argument defaulting to NULL_TREE. * tree-vect-data-refs.c (vect_create_data_ref_ptr): Add byte_offset argument, pass it down to vect_create_addr_base_for_vector_ref. (vect_create_addr_base_for_vector_ref): Add byte_offset argument, add that to base_offset too if non-NULL. * tree-vect-stmts.c (vectorizable_load): Add byte_offset variable, for dr_explicit_realign_optimized set it to vector byte size - 1 instead of setting offset, pass byte_offset down to vect_create_data_ref_ptr. * gcc.dg/vect/pr63341-1.c: New test. * gcc.dg/vect/pr63341-2.c: New test. --- gcc/tree-vectorizer.h.jj 2014-09-01 09:43:56.000000000 +0200 +++ gcc/tree-vectorizer.h 2014-09-23 15:19:28.302484227 +0200 @@ -1061,7 +1061,8 @@ extern bool vect_analyze_data_refs (loop unsigned *); extern tree vect_create_data_ref_ptr (gimple, tree, struct loop *, tree, tree *, gimple_stmt_iterator *, - gimple *, bool, bool *); + gimple *, bool, bool *, + tree = NULL_TREE); extern tree bump_vector_ptr (tree, gimple, gimple_stmt_iterator *, gimple, tree); extern tree vect_create_destination_var (tree, tree); extern bool vect_grouped_store_supported (tree, unsigned HOST_WIDE_INT); @@ -1078,7 +1079,8 @@ extern void vect_transform_grouped_load extern void vect_record_grouped_load_vectors (gimple, vec<tree> ); extern tree vect_get_new_vect_var (tree, enum vect_var_kind, const char *); extern tree vect_create_addr_base_for_vector_ref (gimple, gimple_seq *, - tree, struct loop *); + tree, struct loop *, + tree = NULL_TREE); /* In tree-vect-loop.c. */ /* FORNOW: Used in tree-parloops.c. */ --- gcc/tree-vect-data-refs.c.jj 2014-09-18 15:48:22.000000000 +0200 +++ gcc/tree-vect-data-refs.c 2014-09-23 15:11:06.163061112 +0200 @@ -3860,6 +3860,9 @@ vect_get_new_vect_var (tree type, enum v is as follows: if LOOP=i_loop: &in (relative to i_loop) if LOOP=j_loop: &in+i*2B (relative to j_loop) + BYTE_OFFSET: Optional, defaulted to NULL. If supplied, it is added to the + initial address. Unlike OFFSET, which is number of elements to + be added, BYTE_OFFSET is measured in bytes. Output: 1. Return an SSA_NAME whose value is the address of the memory location of @@ -3873,7 +3876,8 @@ tree vect_create_addr_base_for_vector_ref (gimple stmt, gimple_seq *new_stmt_list, tree offset, - struct loop *loop) + struct loop *loop, + tree byte_offset) { stmt_vec_info stmt_info = vinfo_for_stmt (stmt); struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); @@ -3926,6 +3930,12 @@ vect_create_addr_base_for_vector_ref (gi base_offset = fold_build2 (PLUS_EXPR, sizetype, base_offset, offset); } + if (byte_offset) + { + byte_offset = fold_convert (sizetype, byte_offset); + base_offset = fold_build2 (PLUS_EXPR, sizetype, + base_offset, byte_offset); + } /* base + base_offset */ if (loop_vinfo) @@ -3983,6 +3993,10 @@ vect_create_addr_base_for_vector_ref (gi 5. BSI: location where the new stmts are to be placed if there is no loop 6. ONLY_INIT: indicate if ap is to be updated in the loop, or remain pointing to the initial address. + 7. BYTE_OFFSET (optional, defaults to NULL): a byte offset to be added + to the initial address accessed by the data-ref in STMT. This is + similar to OFFSET, but OFFSET is counted in elements, while BYTE_OFFSET + in bytes. Output: 1. Declare a new ptr to vector_type, and have it point to the base of the @@ -3996,6 +4010,8 @@ vect_create_addr_base_for_vector_ref (gi initial_address = &a[init]; if OFFSET is supplied: initial_address = &a[init + OFFSET]; + if BYTE_OFFSET is supplied: + initial_address = &a[init] + BYTE_OFFSET; Return the initial_address in INITIAL_ADDRESS. @@ -4013,7 +4029,7 @@ tree vect_create_data_ref_ptr (gimple stmt, tree aggr_type, struct loop *at_loop, tree offset, tree *initial_address, gimple_stmt_iterator *gsi, gimple *ptr_incr, - bool only_init, bool *inv_p) + bool only_init, bool *inv_p, tree byte_offset) { const char *base_name; stmt_vec_info stmt_info = vinfo_for_stmt (stmt); @@ -4156,10 +4172,10 @@ vect_create_data_ref_ptr (gimple stmt, t /* (2) Calculate the initial address of the aggregate-pointer, and set the aggregate-pointer to point to it before the loop. */ - /* Create: (&(base[init_val+offset]) in the loop preheader. */ + /* Create: (&(base[init_val+offset]+byte_offset) in the loop preheader. */ new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list, - offset, loop); + offset, loop, byte_offset); if (new_stmt_list) { if (pe) --- gcc/tree-vect-stmts.c.jj 2014-08-01 09:24:12.000000000 +0200 +++ gcc/tree-vect-stmts.c 2014-09-23 15:09:31.832553172 +0200 @@ -5600,6 +5600,7 @@ vectorizable_load (gimple stmt, gimple_s int i, j, group_size, group_gap; tree msq = NULL_TREE, lsq; tree offset = NULL_TREE; + tree byte_offset = NULL_TREE; tree realignment_token = NULL_TREE; gimple phi = NULL; vec<tree> dr_chain = vNULL; @@ -6261,7 +6262,8 @@ vectorizable_load (gimple stmt, gimple_s if (alignment_support_scheme == dr_explicit_realign_optimized) { phi = SSA_NAME_DEF_STMT (msq); - offset = size_int (TYPE_VECTOR_SUBPARTS (vectype) - 1); + byte_offset = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (vectype), + size_one_node); } } else @@ -6302,7 +6304,8 @@ vectorizable_load (gimple stmt, gimple_s dataref_ptr = vect_create_data_ref_ptr (first_stmt, aggr_type, at_loop, offset, &dummy, gsi, &ptr_incr, - simd_lane_access_p, &inv_p); + simd_lane_access_p, &inv_p, + byte_offset); } else if (dataref_offset) dataref_offset = int_const_binop (PLUS_EXPR, dataref_offset, --- gcc/testsuite/gcc.dg/vect/pr63341-1.c.jj 2014-09-23 15:27:24.658025472 +0200 +++ gcc/testsuite/gcc.dg/vect/pr63341-1.c 2014-09-23 15:28:16.645757979 +0200 @@ -0,0 +1,32 @@ +/* PR tree-optimization/63341 */ +/* { dg-do run } */ + +#include "tree-vect.h" + +typedef union U { unsigned short s; unsigned char c; } __attribute__((packed)) U; +struct S { char e __attribute__((aligned (64))); U s[32]; }; +struct S t = {0, {{1}, {2}, {3}, {4}, {5}, {6}, {7}, {8}, + {9}, {10}, {11}, {12}, {13}, {14}, {15}, {16}, + {17}, {18}, {19}, {20}, {21}, {22}, {23}, {24}, + {25}, {26}, {27}, {28}, {29}, {30}, {31}, {32}}}; +unsigned short d[32] = { 1 }; + +__attribute__((noinline, noclone)) void +foo () +{ + int i; + for (i = 0; i < 32; i++) + d[i] = t.s[i].s; + if (__builtin_memcmp (d, t.s, sizeof d)) + abort (); +} + +int +main () +{ + check_vect (); + foo (); + return 0; +} + +/* { dg-final { cleanup-tree-dump "vect" } } */ --- gcc/testsuite/gcc.dg/vect/pr63341-2.c.jj 2014-09-23 15:27:27.906013904 +0200 +++ gcc/testsuite/gcc.dg/vect/pr63341-2.c 2014-09-23 15:30:29.874081634 +0200 @@ -0,0 +1,35 @@ +/* PR tree-optimization/63341 */ +/* { dg-do run } */ + +#include "tree-vect.h" + +typedef union U { unsigned short s; unsigned char c; } __attribute__((packed)) U; +struct S { char e __attribute__((aligned (64))); U s[32]; }; +struct S t = {0, {{0x5010}, {0x5111}, {0x5212}, {0x5313}, {0x5414}, {0x5515}, {0x5616}, {0x5717}, + {0x5818}, {0x5919}, {0x5a1a}, {0x5b1b}, {0x5c1c}, {0x5d1d}, {0x5e1e}, {0x5f1f}, + {0x6020}, {0x6121}, {0x6222}, {0x6323}, {0x6424}, {0x6525}, {0x6626}, {0x6727}, + {0x6828}, {0x6929}, {0x6a2a}, {0x6b2b}, {0x6c2c}, {0x6d2d}, {0x6e2e}, {0x6f2f}}}; +unsigned short d[32] = { 1 }; + +__attribute__((noinline, noclone)) void +foo () +{ + int i; + for (i = 0; i < 32; i++) + d[i] = t.s[i].s + 4; + for (i = 0; i < 32; i++) + if (d[i] != t.s[i].s + 4) + abort (); + else + asm volatile ("" : : : "memory"); +} + +int +main () +{ + check_vect (); + foo (); + return 0; +} + +/* { dg-final { cleanup-tree-dump "vect" } } */ Jakub