Defer decision whether to create Test(x, x) instead of Cmp(x, 0) until peephole optim...

[libfirm] / ir / be / ia32 / ia32_transform.c

diff --git a/ir/be/ia32/ia32_transform.c b/ir/be/ia32/ia32_transform.c
index f4301dd..52d3947 100644 (file)
--- a/ir/be/ia32/ia32_transform.c
+++ b/ir/be/ia32/ia32_transform.c
@@ -2723,64 +2723,31 @@ static ir_node *gen_Cmp(ir_node *node)
 
        assert(ia32_mode_needs_gp_reg(cmp_mode));
 
-       /* we prefer the Test instruction where possible except cases where
-        * we can use SourceAM */
+       /* Prefer the Test instruction, when encountering (x & y) ==/!= 0 */
        cmp_unsigned = !mode_is_signed(cmp_mode);
-       if (is_Const_0(right)) {
-               if (is_And(left) &&
-                               get_irn_n_edges(left) == 1 &&
-                               can_fold_test_and(node)) {
-                       /* Test(and_left, and_right) */
-                       ir_node *and_left  = get_And_left(left);
-                       ir_node *and_right = get_And_right(left);
-                       ir_mode *mode      = get_irn_mode(and_left);
-
-                       match_arguments(&am, block, and_left, and_right, NULL,
-                                       match_commutative |
-                                       match_am | match_8bit_am | match_16bit_am |
-                                       match_am_and_immediates | match_immediate |
-                                       match_8bit | match_16bit);
-                       if (get_mode_size_bits(mode) == 8) {
-                               new_node = new_rd_ia32_Test8Bit(dbgi, irg, new_block, addr->base,
-                                                               addr->index, addr->mem, am.new_op1,
-                                                               am.new_op2, am.ins_permuted,
-                                                               cmp_unsigned);
-                       } else {
-                               new_node = new_rd_ia32_Test(dbgi, irg, new_block, addr->base,
-                                                           addr->index, addr->mem, am.new_op1,
-                                                           am.new_op2, am.ins_permuted, cmp_unsigned);
-                       }
+       if (is_Const_0(right)          &&
+           is_And(left)               &&
+           get_irn_n_edges(left) == 1 &&
+           can_fold_test_and(node)) {
+               /* Test(and_left, and_right) */
+               ir_node *and_left  = get_And_left(left);
+               ir_node *and_right = get_And_right(left);
+               ir_mode *mode      = get_irn_mode(and_left);
+
+               match_arguments(&am, block, and_left, and_right, NULL,
+                                                                               match_commutative |
+                                                                               match_am | match_8bit_am | match_16bit_am |
+                                                                               match_am_and_immediates | match_immediate |
+                                                                               match_8bit | match_16bit);
+               if (get_mode_size_bits(mode) == 8) {
+                       new_node = new_rd_ia32_Test8Bit(dbgi, irg, new_block, addr->base,
+                                                                                                                                                       addr->index, addr->mem, am.new_op1,
+                                                                                                                                                       am.new_op2, am.ins_permuted,
+                                                                                                                                                       cmp_unsigned);
                } else {
-                       match_arguments(&am, block, NULL, left, NULL,
-                                       match_am | match_8bit_am | match_16bit_am |
-                                       match_8bit | match_16bit);
-                       if (am.op_type == ia32_AddrModeS) {
-                               /* Cmp(AM, 0) */
-                               ir_node *imm_zero = try_create_Immediate(right, 0);
-                               if (get_mode_size_bits(cmp_mode) == 8) {
-                                       new_node = new_rd_ia32_Cmp8Bit(dbgi, irg, new_block, addr->base,
-                                                                      addr->index, addr->mem, am.new_op2,
-                                                                      imm_zero, am.ins_permuted,
-                                                                      cmp_unsigned);
-                               } else {
-                                       new_node = new_rd_ia32_Cmp(dbgi, irg, new_block, addr->base,
-                                                                  addr->index, addr->mem, am.new_op2,
-                                                                  imm_zero, am.ins_permuted, cmp_unsigned);
-                               }
-                       } else {
-                               /* Test(left, left) */
-                               if (get_mode_size_bits(cmp_mode) == 8) {
-                                       new_node = new_rd_ia32_Test8Bit(dbgi, irg, new_block, addr->base,
-                                                                       addr->index, addr->mem, am.new_op2,
-                                                                       am.new_op2, am.ins_permuted,
-                                                                       cmp_unsigned);
-                               } else {
-                                       new_node = new_rd_ia32_Test(dbgi, irg, new_block, addr->base,
-                                                                   addr->index, addr->mem, am.new_op2,
-                                                                   am.new_op2, am.ins_permuted,
-                                                                   cmp_unsigned);
-                               }
-                       }
+                       new_node = new_rd_ia32_Test(dbgi, irg, new_block, addr->base,
+                                                                                                                                       addr->index, addr->mem, am.new_op1,
+                                                                                                                                       am.new_op2, am.ins_permuted, cmp_unsigned);
                }
        } else {
                /* Cmp(left, right) */