The following makes copyprop simplify conditions properly (it's
now also copy-propagating constants, thus more opportunities
arise). That fixes the testcase which previously failed to
constant-propagate the __builtin_constant_p result into the asm.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2014-07-14 Richard Biener <rguent...@suse.de>
* tree-ssa-copy.c (copy_prop_visit_cond_stmt): Always try
simplifying a condition.
* gcc.dg/tree-ssa/ssa-copyprop-2.c: New testcase.
Index: gcc/tree-ssa-copy.c
===================================================================
--- gcc/tree-ssa-copy.c (revision 212514)
+++ gcc/tree-ssa-copy.c (working copy)
@@ -237,38 +237,26 @@ copy_prop_visit_cond_stmt (gimple stmt,
enum ssa_prop_result retval = SSA_PROP_VARYING;
location_t loc = gimple_location (stmt);
- tree op0 = gimple_cond_lhs (stmt);
- tree op1 = gimple_cond_rhs (stmt);
+ tree op0 = valueize_val (gimple_cond_lhs (stmt));
+ tree op1 = valueize_val (gimple_cond_rhs (stmt));
- /* The only conditionals that we may be able to compute statically
- are predicates involving two SSA_NAMEs. */
- if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME)
+ /* See if we can determine the predicate's value. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- op0 = valueize_val (op0);
- op1 = valueize_val (op1);
-
- /* See if we can determine the predicate's value. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Trying to determine truth value of ");
- fprintf (dump_file, "predicate ");
- print_gimple_stmt (dump_file, stmt, 0, 0);
- }
+ fprintf (dump_file, "Trying to determine truth value of ");
+ fprintf (dump_file, "predicate ");
+ print_gimple_stmt (dump_file, stmt, 0, 0);
+ }
- /* We can fold COND and get a useful result only when we have
- the same SSA_NAME on both sides of a comparison operator. */
- if (op0 == op1)
- {
- tree folded_cond = fold_binary_loc (loc, gimple_cond_code (stmt),
- boolean_type_node, op0, op1);
- if (folded_cond)
- {
- basic_block bb = gimple_bb (stmt);
- *taken_edge_p = find_taken_edge (bb, folded_cond);
- if (*taken_edge_p)
- retval = SSA_PROP_INTERESTING;
- }
- }
+ /* Fold COND and see whether we get a useful result. */
+ tree folded_cond = fold_binary_loc (loc, gimple_cond_code (stmt),
+ boolean_type_node, op0, op1);
+ if (folded_cond)
+ {
+ basic_block bb = gimple_bb (stmt);
+ *taken_edge_p = find_taken_edge (bb, folded_cond);
+ if (*taken_edge_p)
+ retval = SSA_PROP_INTERESTING;
}
if (dump_file && (dump_flags & TDF_DETAILS) && *taken_edge_p)
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-copyprop-2.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-copyprop-2.c (revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/ssa-copyprop-2.c (working copy)
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-Og -fdump-tree-optimized" } */
+
+extern long long __sdt_unsp;
+void
+f(void)
+{
+ for (;;)
+ __asm__ ("%0" :: "i" (((!__extension__ (__builtin_constant_p ((((unsigned
long long) (__typeof (__builtin_choose_expr (((__builtin_classify_type (0) + 3)
& -4) == 4, (0), 0U))) __sdt_unsp) ) == 0) )) ? 1 : -1) ));
+}
+
+/* { dg-final { scan-tree-dump-not "PHI" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
