On Wed, Jan 14, 2015 at 01:32:13PM +0300, Yuri Rumyantsev wrote:
> Sorry, I resend correct patch.
> +reorder_operands (basic_block bb)
> +{
> + unsigned int *lattice; /* Hold cost of each statement. */
> + unsigned int i = 0, n = 0;
> + gimple_stmt_iterator gsi;
> + gimple_seq stmts;
> + gimple stmt;
> + bool swap;
> + tree op0, op1;
> + ssa_op_iter iter;
> + use_operand_p use_p;
> + enum tree_code code;
> + gimple def0, def1;
> +
> + if (!optimize)
> + return;
Wouldn't it be better to move the !optimize guard to the caller?
> + /* Compute cost of each statement using estimate_num_insns. */
> + stmts = bb_seq (bb);
> + for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
> + {
> + stmt = gsi_stmt (gsi);
> + gimple_set_uid (stmt, n++);
> + }
> + lattice = XALLOCAVEC (unsigned, n);
I'd be afraid that for very large functions you'd ICE here, stack is far
more limited than heap on many hosts. Either give up if n is say .5 million
or above, or allocate from heap in that case?
> + for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
> + {
> + unsigned cost;
> + stmt = gsi_stmt (gsi);
> + cost = estimate_num_insns (stmt, &eni_size_weights);
> + lattice[i] = cost;
> + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE | SSA_OP_VUSE)
Why the SSA_OP_VUSE?
> + if (gimple_code (stmt) != GIMPLE_ASSIGN
!is_gimple_assign (stmt)
instead
> + if (op0 ==NULL_TREE || op1 == NULL_TREE
Missing space after ==.
> + /* Swap operands if the second one is more expensive. */
> + def0 = get_gimple_for_ssa_name (op0);
> + if (!def0)
> + continue;
> + def1 = get_gimple_for_ssa_name (op1);
> + if (!def1)
> + continue;
> + swap = false;
You don't check here if def0/def1 are from the same bb, is that guaranteed?
> + if (swap)
> + {
> + if (dump_file && (dump_flags & TDF_DETAILS))
> + {
> + fprintf (dump_file, "Swap operands in stmt:\n");
> + print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> + }
> + gimple_set_op (stmt, 1, op1);
> + gimple_set_op (stmt, 2, op0);
update_stmt (stmt); ?
> Index: testsuite/gcc.dg/torture/pr64434.c
> ===================================================================
> --- testsuite/gcc.dg/torture/pr64434.c (revision 0)
> +++ testsuite/gcc.dg/torture/pr64434.c (working copy)
>
> Property changes on: testsuite/gcc.dg/torture/pr64434.c
> ___________________________________________________________________
> Added: svn:executable
Please don't make testcases executable.
> ## -0,0 +1 ##
> +*
> \ No newline at end of property
Please avoid these, terminate with newline.
Jakub
