diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/tree-vrp.c | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index a9c31bc..58111f8 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -4359,7 +4359,7 @@ vrp_jump_threader::after_dom_children (basic_block bb) subsequent passes. */ static void -vrp_simplify_cond_using_ranges (vr_values *query, gcond *stmt) +vrp_simplify_cond_using_ranges (range_query *query, gcond *stmt) { tree op0 = gimple_cond_lhs (stmt); tree op1 = gimple_cond_rhs (stmt); @@ -4423,6 +4423,27 @@ vrp_simplify_cond_using_ranges (vr_values *query, gcond *stmt) } } +/* A comparison of an SSA_NAME against a constant where the SSA_NAME + was set by a type conversion can often be rewritten to use the RHS + of the type conversion. Do this optimization for all conditionals + in FUN. + + However, doing so inhibits jump threading through the comparison. + So that transformation is not performed until after jump threading + is complete. */ + +static void +simplify_casted_conds (function *fun, range_query *query) +{ + basic_block bb; + FOR_EACH_BB_FN (bb, fun) + { + gimple *last = last_stmt (bb); + if (last && gimple_code (last) == GIMPLE_COND) + vrp_simplify_cond_using_ranges (query, as_a <gcond *> (last)); + } +} + /* Main entry point to VRP (Value Range Propagation). This pass is loosely based on J. R. C. Patterson, ``Accurate Static Branch Prediction by Value Range Propagation,'' in SIGPLAN Conference on @@ -4519,21 +4540,7 @@ execute_vrp (struct function *fun, bool warn_array_bounds_p) vrp_jump_threader threader (fun, &vrp_vr_values); threader.thread_jumps (); - /* A comparison of an SSA_NAME against a constant where the SSA_NAME - was set by a type conversion can often be rewritten to use the - RHS of the type conversion. - - However, doing so inhibits jump threading through the comparison. - So that transformation is not performed until after jump threading - is complete. */ - basic_block bb; - FOR_EACH_BB_FN (bb, fun) - { - gimple *last = last_stmt (bb); - if (last && gimple_code (last) == GIMPLE_COND) - vrp_simplify_cond_using_ranges (&vrp_vr_values, - as_a <gcond *> (last)); - } + simplify_casted_conds (fun, &vrp_vr_values); free_numbers_of_iterations_estimates (fun); |