diff options
Diffstat (limited to 'gcc/tree-vect-patterns.cc')
| -rw-r--r-- | gcc/tree-vect-patterns.cc | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc index 4f0a7ea..ca19add 100644 --- a/gcc/tree-vect-patterns.cc +++ b/gcc/tree-vect-patterns.cc @@ -6544,10 +6544,22 @@ vect_determine_precisions_from_users (stmt_vec_info stmt_info, gassign *stmt) case RSHIFT_EXPR: { tree shift = gimple_assign_rhs2 (stmt); - if (TREE_CODE (shift) != INTEGER_CST - || !wi::ltu_p (wi::to_widest (shift), precision)) + unsigned int min_const_shift, max_const_shift; + wide_int min_shift, max_shift; + if (TREE_CODE (shift) == SSA_NAME + && vect_get_range_info (shift, &min_shift, &max_shift) + && wi::ge_p (min_shift, 0, TYPE_SIGN (TREE_TYPE (shift))) + && wi::lt_p (max_shift, TYPE_PRECISION (type), + TYPE_SIGN (TREE_TYPE (shift)))) + { + min_const_shift = min_shift.to_uhwi (); + max_const_shift = max_shift.to_uhwi (); + } + else if (TREE_CODE (shift) == INTEGER_CST + && wi::ltu_p (wi::to_widest (shift), precision)) + min_const_shift = max_const_shift = TREE_INT_CST_LOW (shift); + else return; - unsigned int const_shift = TREE_INT_CST_LOW (shift); if (code == LSHIFT_EXPR) { /* Avoid creating an undefined shift. @@ -6559,16 +6571,16 @@ vect_determine_precisions_from_users (stmt_vec_info stmt_info, gassign *stmt) of vectorization. This sort of thing should really be handled before vectorization. */ operation_precision = MAX (stmt_info->min_output_precision, - const_shift + 1); + max_const_shift + 1); /* We need CONST_SHIFT fewer bits of the input. */ - min_input_precision = (MAX (operation_precision, const_shift) - - const_shift); + min_input_precision = (MAX (operation_precision, max_const_shift) + - min_const_shift); } else { /* We need CONST_SHIFT extra bits to do the operation. */ operation_precision = (stmt_info->min_output_precision - + const_shift); + + max_const_shift); min_input_precision = operation_precision; } break; |