From: Richard Guenther Date: Thu, 12 May 2011 12:14:45 +0000 (+0000) Subject: re PR tree-optimization/48172 (incorrect vectorization of loop in GCC 4.5.* with... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e2a3a5f1add296430b85b6b6be24b7340a7bcc9e;p=gcc.git re PR tree-optimization/48172 (incorrect vectorization of loop in GCC 4.5.* with -O3) 2011-05-12 Richard Guenther PR tree-optimization/48172 * tree-vect-loop-manip.c (vect_vfa_segment_size): Do not exclude the number of iterations from the segment size calculation. (vect_create_cond_for_alias_checks): Adjust. * gcc.dg/vect/pr48172.c: New testcase. From-SVN: r173703 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6f994adaedb..71cb451cf26 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2011-05-12 Richard Guenther + + PR tree-optimization/48172 + * tree-vect-loop-manip.c (vect_vfa_segment_size): Do not exclude + the number of iterations from the segment size calculation. + (vect_create_cond_for_alias_checks): Adjust. + 2011-05-12 Jakub Jelinek PR debug/48967 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index b0b337445ad..f6b9ba047dd 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2011-05-12 Richard Guenther + + PR tree-optimization/48172 + * gcc.dg/vect/pr48172.c: New testcase. + 2011-05-12 Jakub Jelinek PR debug/48967 diff --git a/gcc/testsuite/gcc.dg/vect/pr48172.c b/gcc/testsuite/gcc.dg/vect/pr48172.c new file mode 100644 index 00000000000..892aecaf811 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr48172.c @@ -0,0 +1,33 @@ +/* { dg-do run } */ + +extern void *memset(void *s, int c, __SIZE_TYPE__ n); +extern void abort (void); + +#define ASIZE 1028 +#define HALF (ASIZE/2) + +int main() { + unsigned int array[ASIZE]; + int i; + + memset(array, 0, sizeof(array)); + + /* initialize first half of the array */ + for (i = 0; i < HALF; i++) + array[i] = i; + + /* fill second half of array in by summing earlier elements of the array + gcc 4.5.1 and 4.5.2 incorrectly vectorize this loop! aray[1025] is left + at 0 for ASIZE=1028 */ + for (i = 0; i < HALF-1; i++) + array[HALF+i] = array[2*i] + array[2*i + 1]; + + /* see if we have any failures */ + for (i = 0; i < HALF - 1; i++) + if (array[HALF+i] != array[2*i] + array[2*i + 1]) + abort (); + + return 0; +} + +/* { dg-final { cleanup-tree-dump "vect" } } */ diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c index 28b75f1ecbb..d990e7f45f8 100644 --- a/gcc/tree-vect-loop-manip.c +++ b/gcc/tree-vect-loop-manip.c @@ -2354,26 +2354,31 @@ vect_create_cond_for_align_checks (loop_vec_info loop_vinfo, Input: DR: The data reference. VECT_FACTOR: vectorization factor. + SCALAR_LOOP_NITERS: number of iterations. Return an expression whose value is the size of segment which will be accessed by DR. */ static tree -vect_vfa_segment_size (struct data_reference *dr, tree vect_factor) +vect_vfa_segment_size (struct data_reference *dr, int vect_factor, + tree scalar_loop_niters) { - tree segment_length = fold_build2 (MULT_EXPR, integer_type_node, - DR_STEP (dr), vect_factor); - + tree segment_length; + segment_length = size_binop (MULT_EXPR, + fold_convert (sizetype, DR_STEP (dr)), + size_int (vect_factor)); + segment_length = size_binop (MULT_EXPR, + segment_length, + fold_convert (sizetype, scalar_loop_niters)); if (vect_supportable_dr_alignment (dr, false) == dr_explicit_realign_optimized) { tree vector_size = TYPE_SIZE_UNIT (STMT_VINFO_VECTYPE (vinfo_for_stmt (DR_STMT (dr)))); - segment_length = fold_build2 (PLUS_EXPR, integer_type_node, - segment_length, vector_size); + segment_length = size_binop (PLUS_EXPR, segment_length, vector_size); } - return fold_convert (sizetype, segment_length); + return segment_length; } @@ -2407,8 +2412,8 @@ vect_create_cond_for_alias_checks (loop_vec_info loop_vinfo, struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); VEC (ddr_p, heap) * may_alias_ddrs = LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo); - tree vect_factor = - build_int_cst (integer_type_node, LOOP_VINFO_VECT_FACTOR (loop_vinfo)); + int vect_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + tree scalar_loop_iters = LOOP_VINFO_NITERS (loop_vinfo); ddr_p ddr; unsigned int i; @@ -2460,8 +2465,10 @@ vect_create_cond_for_alias_checks (loop_vec_info loop_vinfo, vect_create_addr_base_for_vector_ref (stmt_b, cond_expr_stmt_list, NULL_TREE, loop); - segment_length_a = vect_vfa_segment_size (dr_a, vect_factor); - segment_length_b = vect_vfa_segment_size (dr_b, vect_factor); + segment_length_a = vect_vfa_segment_size (dr_a, vect_factor, + scalar_loop_iters); + segment_length_b = vect_vfa_segment_size (dr_b, vect_factor, + scalar_loop_iters); if (vect_print_dump_info (REPORT_DR_DETAILS)) {