improve comments, remove unnecessary test

[r25931]

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index 08208af..4af00e0 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -3281,6 +3281,7 @@ static ir_node *transform_bitwise_distributive(ir_node *n,
        if(op != get_irn_op(b))
                return n;
 
+       /* and(conv(a), conv(b)) -> conv(and(a,b)) */
        if (op == op_Conv) {
                ir_node *a_op   = get_Conv_op(a);
                ir_node *b_op   = get_Conv_op(b);
@@ -5497,7 +5498,7 @@ static ir_node *transform_node_Mux(ir_node *n) {
                ir_node*  t1    = get_Mux_true(t);
                ir_node*  f1    = get_Mux_false(t);
                if (f == f1) {
-                       /* Mux(c0, Mux(c1, x, y), y) -> typical if (c0 && c1) x else y */
+                       /* Mux(cond0, Mux(cond1, x, y), y) -> typical if (cond0 && cond1) x else y */
                        ir_node* and_    = new_r_And(irg, block, c0, c1, mode_b);
                        ir_node* new_mux = new_r_Mux(irg, block, and_, f1, t1, mode);
                        n   = new_mux;
@@ -5506,7 +5507,7 @@ static ir_node *transform_node_Mux(ir_node *n) {
                        t   = t1;
                        DBG_OPT_ALGSIM0(oldn, t, FS_OPT_MUX_COMBINE);
                } else if (f == t1) {
-                       /* Mux(c0, Mux(c1, x, y), x) */
+                       /* Mux(cond0, Mux(cond1, x, y), x) */
                        ir_node* not_c1  = new_r_Not(irg, block, c1, mode_b);
                        ir_node* and_    = new_r_And(irg, block, c0, not_c1, mode_b);
                        ir_node* new_mux = new_r_Mux(irg, block, and_, t1, f1, mode);
@@ -5523,7 +5524,7 @@ static ir_node *transform_node_Mux(ir_node *n) {
                ir_node*  t1    = get_Mux_true(f);
                ir_node*  f1    = get_Mux_false(f);
                if (t == t1) {
-                       /* Mux(c0, x, Mux(c1, x, y)) -> typical if (c0 || c1) x else y */
+                       /* Mux(cond0, x, Mux(cond1, x, y)) -> typical if (cond0 || cond1) x else y */
                        ir_node* or_     = new_r_Or(irg, block, c0, c1, mode_b);
                        ir_node* new_mux = new_r_Mux(irg, block, or_, f1, t1, mode);
                        n   = new_mux;
@@ -5532,7 +5533,7 @@ static ir_node *transform_node_Mux(ir_node *n) {
                        t   = t1;
                        DBG_OPT_ALGSIM0(oldn, f, FS_OPT_MUX_COMBINE);
                } else if (t == f1) {
-                       /* Mux(c0, x, Mux(c1, y, x)) */
+                       /* Mux(cond0, x, Mux(cond1, y, x)) */
                        ir_node* not_c1  = new_r_Not(irg, block, c1, mode_b);
                        ir_node* or_     = new_r_Or(irg, block, c0, not_c1, mode_b);
                        ir_node* new_mux = new_r_Mux(irg, block, or_, t1, f1, mode);
@@ -5610,21 +5611,19 @@ static ir_node *transform_node_Mux(ir_node *n) {
                tarval *null = get_tarval_null(mode);
                tarval *diff, *min;
 
-               if (get_opt_allow_conv_b()) {
-                       if (tarval_is_one(a) && tarval_is_null(b)) {
-                               ir_node *block = get_nodes_block(n);
-                               ir_node *conv  = new_r_Conv(current_ir_graph, block, sel, mode);
-                               n = conv;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
-                               return n;
-                       } else if (tarval_is_null(a) && tarval_is_one(b)) {
-                               ir_node *block = get_nodes_block(n);
-                               ir_node *not_  = new_r_Not(current_ir_graph, block, sel, mode_b);
-                               ir_node *conv  = new_r_Conv(current_ir_graph, block, not_, mode);
-                               n = conv;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
-                               return n;
-                       }
+               if (tarval_is_one(a) && tarval_is_null(b)) {
+                       ir_node *block = get_nodes_block(n);
+                       ir_node *conv  = new_r_Conv(current_ir_graph, block, sel, mode);
+                       n = conv;
+                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
+                       return n;
+               } else if (tarval_is_null(a) && tarval_is_one(b)) {
+                       ir_node *block = get_nodes_block(n);
+                       ir_node *not_  = new_r_Not(current_ir_graph, block, sel, mode_b);
+                       ir_node *conv  = new_r_Conv(current_ir_graph, block, not_, mode);
+                       n = conv;
+                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
+                       return n;
                }
                /* TODO: it's not really clear if that helps in general or should be moved
                 * to backend, especially with the MUX->Conv transformation above */