diff options
Diffstat (limited to 'gcc/tree-ssa-phiopt.c')
| -rw-r--r-- | gcc/tree-ssa-phiopt.c | 61 |
1 files changed, 47 insertions, 14 deletions
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index aa6bb88..3d40f07 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -337,7 +337,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) } /* Do the replacement of conditional if it can be done. */ - if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) + if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) cfgchanged = true; else if (!early_p && conditional_replacement (bb, bb1, e1, e2, phi, @@ -635,7 +635,6 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb, if (TREE_CODE (lhs) != SSA_NAME || !INTEGRAL_TYPE_P (TREE_TYPE (lhs)) - || TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE || TREE_CODE (rhs) != INTEGER_CST) return false; @@ -648,9 +647,25 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb, return false; } + /* Defer boolean x ? 0 : {1,-1} or x ? {1,-1} : 0 to + conditional_replacement. */ + if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE + && (integer_zerop (arg0) + || integer_zerop (arg1) + || TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE + || (TYPE_PRECISION (TREE_TYPE (arg0)) + <= TYPE_PRECISION (TREE_TYPE (lhs))))) + return false; + wide_int min, max; - if (get_range_info (lhs, &min, &max) != VR_RANGE - || min + 1 != max + if (get_range_info (lhs, &min, &max) != VR_RANGE) + { + int prec = TYPE_PRECISION (TREE_TYPE (lhs)); + signop sgn = TYPE_SIGN (TREE_TYPE (lhs)); + min = wi::min_value (prec, sgn); + max = wi::max_value (prec, sgn); + } + if (min + 1 != max || (wi::to_wide (rhs) != min && wi::to_wide (rhs) != max)) return false; @@ -752,7 +767,9 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb, gimple_stmt_iterator gsi; edge true_edge, false_edge; tree new_var, new_var2; - bool neg; + bool neg = false; + int shift = 0; + tree nonzero_arg; /* FIXME: Gimplification of complex type is too hard for now. */ /* We aren't prepared to handle vectors either (and it is a question @@ -763,14 +780,22 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb, || POINTER_TYPE_P (TREE_TYPE (arg1)))) return false; - /* The PHI arguments have the constants 0 and 1, or 0 and -1, then - convert it to the conditional. */ - if ((integer_zerop (arg0) && integer_onep (arg1)) - || (integer_zerop (arg1) && integer_onep (arg0))) - neg = false; - else if ((integer_zerop (arg0) && integer_all_onesp (arg1)) - || (integer_zerop (arg1) && integer_all_onesp (arg0))) + /* The PHI arguments have the constants 0 and 1, or 0 and -1 or + 0 and (1 << cst), then convert it to the conditional. */ + if (integer_zerop (arg0)) + nonzero_arg = arg1; + else if (integer_zerop (arg1)) + nonzero_arg = arg0; + else + return false; + if (integer_all_onesp (nonzero_arg)) neg = true; + else if (integer_pow2p (nonzero_arg)) + { + shift = tree_log2 (nonzero_arg); + if (shift && POINTER_TYPE_P (TREE_TYPE (nonzero_arg))) + return false; + } else return false; @@ -782,12 +807,12 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb, falls through into BB. There is a single PHI node at the join point (BB) and its arguments - are constants (0, 1) or (0, -1). + are constants (0, 1) or (0, -1) or (0, (1 << shift)). So, given the condition COND, and the two PHI arguments, we can rewrite this PHI into non-branching code: - dest = (COND) or dest = COND' + dest = (COND) or dest = COND' or dest = (COND) << shift We use the condition as-is if the argument associated with the true edge has the value one or the argument associated with the @@ -822,6 +847,14 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb, cond = fold_build1_loc (gimple_location (stmt), NEGATE_EXPR, TREE_TYPE (cond), cond); } + else if (shift) + { + cond = fold_convert_loc (gimple_location (stmt), + TREE_TYPE (result), cond); + cond = fold_build2_loc (gimple_location (stmt), + LSHIFT_EXPR, TREE_TYPE (cond), cond, + build_int_cst (integer_type_node, shift)); + } /* Insert our new statements at the end of conditional block before the COND_STMT. */ |