2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Implements several optimizations for IA32.
23 * @author Matthias Braun, Christian Wuerdig
32 #include "firm_types.h"
45 #include "../benode.h"
46 #include "../besched.h"
47 #include "../bepeephole.h"
49 #include "ia32_new_nodes.h"
50 #include "ia32_optimize.h"
51 #include "bearch_ia32_t.h"
52 #include "gen_ia32_regalloc_if.h"
53 #include "ia32_common_transform.h"
54 #include "ia32_transform.h"
55 #include "ia32_dbg_stat.h"
56 #include "ia32_util.h"
57 #include "ia32_architecture.h"
59 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
61 static void copy_mark(const ir_node *old, ir_node *newn)
63 if (is_ia32_is_reload(old))
64 set_ia32_is_reload(newn);
65 if (is_ia32_is_spill(old))
66 set_ia32_is_spill(newn);
67 if (is_ia32_is_remat(old))
68 set_ia32_is_remat(newn);
71 typedef enum produces_flag_t {
78 * Return which usable flag the given node produces
80 * @param node the node to check
81 * @param pn the projection number of the used result
83 static produces_flag_t produces_test_flag(ir_node *node, int pn)
86 const ia32_immediate_attr_t *imm_attr;
88 if (!is_ia32_irn(node))
89 return produces_no_flag;
91 switch (get_ia32_irn_opcode(node)) {
106 assert((int)n_ia32_ShlD_count == (int)n_ia32_ShrD_count);
107 count = get_irn_n(node, n_ia32_ShlD_count);
108 goto check_shift_amount;
113 assert((int)n_ia32_Shl_count == (int)n_ia32_Shr_count
114 && (int)n_ia32_Shl_count == (int)n_ia32_Sar_count);
115 count = get_irn_n(node, n_ia32_Shl_count);
117 /* when shift count is zero the flags are not affected, so we can only
118 * do this for constants != 0 */
119 if (!is_ia32_Immediate(count))
120 return produces_no_flag;
122 imm_attr = get_ia32_immediate_attr_const(count);
123 if (imm_attr->symconst != NULL)
124 return produces_no_flag;
125 if ((imm_attr->offset & 0x1f) == 0)
126 return produces_no_flag;
130 return pn == pn_ia32_Mul_res_high ?
131 produces_flag_carry : produces_no_flag;
134 return produces_no_flag;
137 return pn == pn_ia32_res ?
138 produces_flag_zero : produces_no_flag;
142 * Replace Cmp(x, 0) by a Test(x, x)
144 static void peephole_ia32_Cmp(ir_node *const node)
148 ia32_immediate_attr_t const *imm;
154 ia32_attr_t const *attr;
157 arch_register_t const *reg;
158 ir_edge_t const *edge;
159 ir_edge_t const *tmp;
161 if (get_ia32_op_type(node) != ia32_Normal)
164 right = get_irn_n(node, n_ia32_Cmp_right);
165 if (!is_ia32_Immediate(right))
168 imm = get_ia32_immediate_attr_const(right);
169 if (imm->symconst != NULL || imm->offset != 0)
172 dbgi = get_irn_dbg_info(node);
173 irg = get_irn_irg(node);
174 block = get_nodes_block(node);
175 noreg = ia32_new_NoReg_gp(irg);
176 nomem = get_irg_no_mem(current_ir_graph);
177 op = get_irn_n(node, n_ia32_Cmp_left);
178 attr = get_ia32_attr(node);
179 ins_permuted = attr->data.ins_permuted;
181 if (is_ia32_Cmp(node)) {
182 test = new_bd_ia32_Test(dbgi, block, noreg, noreg, nomem,
183 op, op, ins_permuted);
185 test = new_bd_ia32_Test8Bit(dbgi, block, noreg, noreg, nomem,
186 op, op, ins_permuted);
188 set_ia32_ls_mode(test, get_ia32_ls_mode(node));
190 reg = arch_irn_get_register(node, pn_ia32_Cmp_eflags);
191 arch_irn_set_register(test, pn_ia32_Test_eflags, reg);
193 foreach_out_edge_safe(node, edge, tmp) {
194 ir_node *const user = get_edge_src_irn(edge);
197 exchange(user, test);
200 sched_add_before(node, test);
201 copy_mark(node, test);
202 be_peephole_exchange(node, test);
206 * Peephole optimization for Test instructions.
207 * - Remove the Test, if an appropriate flag was produced which is still live
208 * - Change a Test(x, c) to 8Bit, if 0 <= c < 256 (3 byte shorter opcode)
210 static void peephole_ia32_Test(ir_node *node)
212 ir_node *left = get_irn_n(node, n_ia32_Test_left);
213 ir_node *right = get_irn_n(node, n_ia32_Test_right);
215 assert((int)n_ia32_Test_left == (int)n_ia32_Test8Bit_left
216 && (int)n_ia32_Test_right == (int)n_ia32_Test8Bit_right);
218 if (left == right) { /* we need a test for 0 */
219 ir_node *block = get_nodes_block(node);
220 int pn = pn_ia32_res;
224 const ir_edge_t *edge;
226 if (get_nodes_block(left) != block)
230 pn = get_Proj_proj(left);
231 left = get_Proj_pred(left);
234 /* walk schedule up and abort when we find left or some other node
235 * destroys the flags */
238 schedpoint = sched_prev(schedpoint);
239 if (schedpoint == left)
241 if (arch_irn_is(schedpoint, modify_flags))
243 if (schedpoint == block)
244 panic("couldn't find left");
247 /* make sure only Lg/Eq tests are used */
248 foreach_out_edge(node, edge) {
249 ir_node *user = get_edge_src_irn(edge);
250 ia32_condition_code_t cc = get_ia32_condcode(user);
252 if (cc != ia32_cc_equal && cc != ia32_cc_not_equal) {
257 switch (produces_test_flag(left, pn)) {
258 case produces_flag_zero:
261 case produces_flag_carry:
262 foreach_out_edge(node, edge) {
263 ir_node *user = get_edge_src_irn(edge);
264 ia32_condition_code_t cc = get_ia32_condcode(user);
267 case ia32_cc_equal: cc = ia32_cc_above_equal; break; /* CF = 0 */
268 case ia32_cc_not_equal: cc = ia32_cc_below; break; /* CF = 1 */
269 default: panic("unexpected pn");
271 set_ia32_condcode(user, cc);
279 if (get_irn_mode(left) != mode_T) {
280 set_irn_mode(left, mode_T);
282 /* If there are other users, reroute them to result proj */
283 if (get_irn_n_edges(left) != 2) {
284 ir_node *res = new_r_Proj(left, mode_Iu, pn_ia32_res);
286 edges_reroute(left, res, current_ir_graph);
287 /* Reattach the result proj to left */
288 set_Proj_pred(res, left);
292 flags_mode = ia32_reg_classes[CLASS_ia32_flags].mode;
293 flags_proj = new_r_Proj(left, flags_mode, pn_ia32_flags);
294 arch_set_irn_register(flags_proj, &ia32_registers[REG_EFLAGS]);
296 assert(get_irn_mode(node) != mode_T);
298 be_peephole_exchange(node, flags_proj);
299 } else if (is_ia32_Immediate(right)) {
300 ia32_immediate_attr_t const *const imm = get_ia32_immediate_attr_const(right);
303 /* A test with a symconst is rather strange, but better safe than sorry */
304 if (imm->symconst != NULL)
307 offset = imm->offset;
308 if (get_ia32_op_type(node) == ia32_AddrModeS) {
309 ia32_attr_t *const attr = get_ia32_attr(node);
311 if ((offset & 0xFFFFFF00) == 0) {
312 /* attr->am_offs += 0; */
313 } else if ((offset & 0xFFFF00FF) == 0) {
314 ir_node *imm = ia32_create_Immediate(NULL, 0, offset >> 8);
315 set_irn_n(node, n_ia32_Test_right, imm);
317 } else if ((offset & 0xFF00FFFF) == 0) {
318 ir_node *imm = ia32_create_Immediate(NULL, 0, offset >> 16);
319 set_irn_n(node, n_ia32_Test_right, imm);
321 } else if ((offset & 0x00FFFFFF) == 0) {
322 ir_node *imm = ia32_create_Immediate(NULL, 0, offset >> 24);
323 set_irn_n(node, n_ia32_Test_right, imm);
328 } else if (offset < 256) {
329 arch_register_t const* const reg = arch_get_irn_register(left);
331 if (reg != &ia32_registers[REG_EAX] &&
332 reg != &ia32_registers[REG_EBX] &&
333 reg != &ia32_registers[REG_ECX] &&
334 reg != &ia32_registers[REG_EDX]) {
341 /* Technically we should build a Test8Bit because of the register
342 * constraints, but nobody changes registers at this point anymore. */
343 set_ia32_ls_mode(node, mode_Bu);
348 * AMD Athlon works faster when RET is not destination of
349 * conditional jump or directly preceded by other jump instruction.
350 * Can be avoided by placing a Rep prefix before the return.
352 static void peephole_ia32_Return(ir_node *node)
354 ir_node *block, *irn;
356 if (!ia32_cg_config.use_pad_return)
359 block = get_nodes_block(node);
361 /* check if this return is the first on the block */
362 sched_foreach_reverse_from(node, irn) {
363 switch (get_irn_opcode(irn)) {
365 /* the return node itself, ignore */
370 /* ignore no code generated */
373 /* arg, IncSP 0 nodes might occur, ignore these */
374 if (be_get_IncSP_offset(irn) == 0)
384 /* ensure, that the 3 byte return is generated */
385 be_Return_set_emit_pop(node, 1);
388 /* only optimize up to 48 stores behind IncSPs */
389 #define MAXPUSH_OPTIMIZE 48
392 * Tries to create Push's from IncSP, Store combinations.
393 * The Stores are replaced by Push's, the IncSP is modified
394 * (possibly into IncSP 0, but not removed).
396 static void peephole_IncSP_Store_to_push(ir_node *irn)
402 ir_node *stores[MAXPUSH_OPTIMIZE];
407 ir_node *first_push = NULL;
408 ir_edge_t const *edge;
409 ir_edge_t const *next;
411 memset(stores, 0, sizeof(stores));
413 assert(be_is_IncSP(irn));
415 inc_ofs = be_get_IncSP_offset(irn);
420 * We first walk the schedule after the IncSP node as long as we find
421 * suitable Stores that could be transformed to a Push.
422 * We save them into the stores array which is sorted by the frame offset/4
423 * attached to the node
426 for (node = sched_next(irn); !sched_is_end(node); node = sched_next(node)) {
431 /* it has to be a Store */
432 if (!is_ia32_Store(node))
435 /* it has to use our sp value */
436 if (get_irn_n(node, n_ia32_base) != irn)
438 /* Store has to be attached to NoMem */
439 mem = get_irn_n(node, n_ia32_mem);
443 /* unfortunately we can't support the full AMs possible for push at the
444 * moment. TODO: fix this */
445 if (!is_ia32_NoReg_GP(get_irn_n(node, n_ia32_index)))
448 offset = get_ia32_am_offs_int(node);
449 /* we should NEVER access uninitialized stack BELOW the current SP */
452 /* storing at half-slots is bad */
453 if ((offset & 3) != 0)
456 if (inc_ofs - 4 < offset || offset >= MAXPUSH_OPTIMIZE * 4)
458 storeslot = offset >> 2;
460 /* storing into the same slot twice is bad (and shouldn't happen...) */
461 if (stores[storeslot] != NULL)
464 stores[storeslot] = node;
465 if (storeslot > maxslot)
471 for (i = -1; i < maxslot; ++i) {
472 if (stores[i + 1] == NULL)
476 /* walk through the Stores and create Pushs for them */
477 block = get_nodes_block(irn);
478 spmode = get_irn_mode(irn);
479 irg = get_irn_irg(irn);
480 for (; i >= 0; --i) {
481 const arch_register_t *spreg;
483 ir_node *val, *mem, *mem_proj;
484 ir_node *store = stores[i];
485 ir_node *noreg = ia32_new_NoReg_gp(irg);
487 val = get_irn_n(store, n_ia32_unary_op);
488 mem = get_irn_n(store, n_ia32_mem);
489 spreg = arch_get_irn_register(curr_sp);
491 push = new_bd_ia32_Push(get_irn_dbg_info(store), block, noreg, noreg, mem, val, curr_sp);
492 copy_mark(store, push);
494 if (first_push == NULL)
497 sched_add_after(skip_Proj(curr_sp), push);
499 /* create stackpointer Proj */
500 curr_sp = new_r_Proj(push, spmode, pn_ia32_Push_stack);
501 arch_set_irn_register(curr_sp, spreg);
503 /* create memory Proj */
504 mem_proj = new_r_Proj(push, mode_M, pn_ia32_Push_M);
506 /* use the memproj now */
507 be_peephole_exchange(store, mem_proj);
512 foreach_out_edge_safe(irn, edge, next) {
513 ir_node *const src = get_edge_src_irn(edge);
514 int const pos = get_edge_src_pos(edge);
516 if (src == first_push)
519 set_irn_n(src, pos, curr_sp);
522 be_set_IncSP_offset(irn, inc_ofs);
527 * Creates a Push instruction before the given schedule point.
529 * @param dbgi debug info
530 * @param block the block
531 * @param stack the previous stack value
532 * @param schedpoint the new node is added before this node
533 * @param reg the register to pop
535 * @return the new stack value
537 static ir_node *create_push(dbg_info *dbgi, ir_node *block,
538 ir_node *stack, ir_node *schedpoint)
540 const arch_register_t *esp = &ia32_registers[REG_ESP];
542 ir_node *val = ia32_new_NoReg_gp(cg);
543 ir_node *noreg = ia32_new_NoReg_gp(cg);
544 ir_graph *irg = get_irn_irg(block);
545 ir_node *nomem = new_r_NoMem(irg);
546 ir_node *push = new_bd_ia32_Push(dbgi, block, noreg, noreg, nomem, val, stack);
547 sched_add_before(schedpoint, push);
549 stack = new_r_Proj(push, mode_Iu, pn_ia32_Push_stack);
550 arch_set_irn_register(stack, esp);
555 static void peephole_store_incsp(ir_node *store)
566 ir_node *am_base = get_irn_n(store, n_ia32_Store_base);
567 if (!be_is_IncSP(am_base)
568 || get_nodes_block(am_base) != get_nodes_block(store))
570 mem = get_irn_n(store, n_ia32_Store_mem);
571 if (!is_ia32_NoReg_GP(get_irn_n(store, n_ia32_Store_index))
575 int incsp_offset = be_get_IncSP_offset(am_base);
576 if (incsp_offset <= 0)
579 /* we have to be at offset 0 */
580 int my_offset = get_ia32_am_offs_int(store);
581 if (my_offset != 0) {
582 /* TODO here: find out wether there is a store with offset 0 before
583 * us and wether we can move it down to our place */
586 ir_mode *ls_mode = get_ia32_ls_mode(store);
587 int my_store_size = get_mode_size_bytes(ls_mode);
589 if (my_offset + my_store_size > incsp_offset)
592 /* correctness checking:
593 - noone else must write to that stackslot
594 (because after translation incsp won't allocate it anymore)
596 sched_foreach_reverse_from(store, node) {
602 /* make sure noone else can use the space on the stack */
603 arity = get_irn_arity(node);
604 for (i = 0; i < arity; ++i) {
605 ir_node *pred = get_irn_n(node, i);
609 if (i == n_ia32_base &&
610 (get_ia32_op_type(node) == ia32_AddrModeS
611 || get_ia32_op_type(node) == ia32_AddrModeD)) {
612 int node_offset = get_ia32_am_offs_int(node);
613 ir_mode *node_ls_mode = get_ia32_ls_mode(node);
614 int node_size = get_mode_size_bytes(node_ls_mode);
615 /* overlapping with our position? abort */
616 if (node_offset < my_offset + my_store_size
617 && node_offset + node_size >= my_offset)
619 /* otherwise it's fine */
623 /* strange use of esp: abort */
628 /* all ok, change to push */
629 dbgi = get_irn_dbg_info(store);
630 block = get_nodes_block(store);
631 noreg = ia32_new_NoReg_gp(cg);
632 val = get_irn_n(store, n_ia32_Store_val);
634 push = new_bd_ia32_Push(dbgi, block, noreg, noreg, mem,
636 create_push(dbgi, current_ir_graph, block, am_base, store);
641 * Return true if a mode can be stored in the GP register set
643 static inline int mode_needs_gp_reg(ir_mode *mode)
645 if (mode == ia32_mode_fpcw)
647 if (get_mode_size_bits(mode) > 32)
649 return mode_is_int(mode) || mode_is_reference(mode) || mode == mode_b;
653 * Tries to create Pops from Load, IncSP combinations.
654 * The Loads are replaced by Pops, the IncSP is modified
655 * (possibly into IncSP 0, but not removed).
657 static void peephole_Load_IncSP_to_pop(ir_node *irn)
659 const arch_register_t *esp = &ia32_registers[REG_ESP];
660 int i, maxslot, inc_ofs, ofs;
661 ir_node *node, *pred_sp, *block;
662 ir_node *loads[MAXPUSH_OPTIMIZE];
664 unsigned regmask = 0;
665 unsigned copymask = ~0;
667 memset(loads, 0, sizeof(loads));
668 assert(be_is_IncSP(irn));
670 inc_ofs = -be_get_IncSP_offset(irn);
675 * We first walk the schedule before the IncSP node as long as we find
676 * suitable Loads that could be transformed to a Pop.
677 * We save them into the stores array which is sorted by the frame offset/4
678 * attached to the node
681 pred_sp = be_get_IncSP_pred(irn);
682 for (node = sched_prev(irn); !sched_is_end(node); node = sched_prev(node)) {
685 const arch_register_t *sreg, *dreg;
687 /* it has to be a Load */
688 if (!is_ia32_Load(node)) {
689 if (be_is_Copy(node)) {
690 if (!mode_needs_gp_reg(get_irn_mode(node))) {
691 /* not a GP copy, ignore */
694 dreg = arch_get_irn_register(node);
695 sreg = arch_get_irn_register(be_get_Copy_op(node));
696 if (regmask & copymask & (1 << sreg->index)) {
699 if (regmask & copymask & (1 << dreg->index)) {
702 /* we CAN skip Copies if neither the destination nor the source
703 * is not in our regmask, ie none of our future Pop will overwrite it */
704 regmask |= (1 << dreg->index) | (1 << sreg->index);
705 copymask &= ~((1 << dreg->index) | (1 << sreg->index));
711 /* we can handle only GP loads */
712 if (!mode_needs_gp_reg(get_ia32_ls_mode(node)))
715 /* it has to use our predecessor sp value */
716 if (get_irn_n(node, n_ia32_base) != pred_sp) {
717 /* it would be ok if this load does not use a Pop result,
718 * but we do not check this */
722 /* should have NO index */
723 if (!is_ia32_NoReg_GP(get_irn_n(node, n_ia32_index)))
726 offset = get_ia32_am_offs_int(node);
727 /* we should NEVER access uninitialized stack BELOW the current SP */
730 /* storing at half-slots is bad */
731 if ((offset & 3) != 0)
734 if (offset < 0 || offset >= MAXPUSH_OPTIMIZE * 4)
736 /* ignore those outside the possible windows */
737 if (offset > inc_ofs - 4)
739 loadslot = offset >> 2;
741 /* loading from the same slot twice is bad (and shouldn't happen...) */
742 if (loads[loadslot] != NULL)
745 dreg = arch_irn_get_register(node, pn_ia32_Load_res);
746 if (regmask & (1 << dreg->index)) {
747 /* this register is already used */
750 regmask |= 1 << dreg->index;
752 loads[loadslot] = node;
753 if (loadslot > maxslot)
760 /* find the first slot */
761 for (i = maxslot; i >= 0; --i) {
762 ir_node *load = loads[i];
768 ofs = inc_ofs - (maxslot + 1) * 4;
771 /* create a new IncSP if needed */
772 block = get_nodes_block(irn);
773 irg = get_irn_irg(irn);
775 pred_sp = be_new_IncSP(esp, block, pred_sp, -inc_ofs, be_get_IncSP_align(irn));
776 sched_add_before(irn, pred_sp);
779 /* walk through the Loads and create Pops for them */
780 for (++i; i <= maxslot; ++i) {
781 ir_node *load = loads[i];
783 const ir_edge_t *edge, *tmp;
784 const arch_register_t *reg;
786 mem = get_irn_n(load, n_ia32_mem);
787 reg = arch_irn_get_register(load, pn_ia32_Load_res);
789 pop = new_bd_ia32_Pop(get_irn_dbg_info(load), block, mem, pred_sp);
790 arch_irn_set_register(pop, pn_ia32_Load_res, reg);
792 copy_mark(load, pop);
794 /* create stackpointer Proj */
795 pred_sp = new_r_Proj(pop, mode_Iu, pn_ia32_Pop_stack);
796 arch_set_irn_register(pred_sp, esp);
798 sched_add_before(irn, pop);
801 foreach_out_edge_safe(load, edge, tmp) {
802 ir_node *proj = get_edge_src_irn(edge);
804 set_Proj_pred(proj, pop);
807 /* we can remove the Load now */
812 be_set_IncSP_offset(irn, -ofs);
813 be_set_IncSP_pred(irn, pred_sp);
818 * Find a free GP register if possible, else return NULL.
820 static const arch_register_t *get_free_gp_reg(ir_graph *irg)
822 be_irg_t *birg = be_birg_from_irg(irg);
825 for (i = 0; i < N_ia32_gp_REGS; ++i) {
826 const arch_register_t *reg = &ia32_reg_classes[CLASS_ia32_gp].regs[i];
827 if (!rbitset_is_set(birg->allocatable_regs, reg->global_index))
830 if (be_peephole_get_value(CLASS_ia32_gp, i) == NULL)
838 * Creates a Pop instruction before the given schedule point.
840 * @param dbgi debug info
841 * @param block the block
842 * @param stack the previous stack value
843 * @param schedpoint the new node is added before this node
844 * @param reg the register to pop
846 * @return the new stack value
848 static ir_node *create_pop(dbg_info *dbgi, ir_node *block,
849 ir_node *stack, ir_node *schedpoint,
850 const arch_register_t *reg)
852 const arch_register_t *esp = &ia32_registers[REG_ESP];
853 ir_graph *irg = get_irn_irg(block);
859 pop = new_bd_ia32_Pop(dbgi, block, new_r_NoMem(irg), stack);
861 stack = new_r_Proj(pop, mode_Iu, pn_ia32_Pop_stack);
862 arch_set_irn_register(stack, esp);
863 val = new_r_Proj(pop, mode_Iu, pn_ia32_Pop_res);
864 arch_set_irn_register(val, reg);
866 sched_add_before(schedpoint, pop);
869 keep = be_new_Keep(block, 1, in);
870 sched_add_before(schedpoint, keep);
876 * Optimize an IncSp by replacing it with Push/Pop.
878 static void peephole_be_IncSP(ir_node *node)
880 const arch_register_t *esp = &ia32_registers[REG_ESP];
881 const arch_register_t *reg;
887 /* first optimize incsp->incsp combinations */
888 node = be_peephole_IncSP_IncSP(node);
890 /* transform IncSP->Store combinations to Push where possible */
891 peephole_IncSP_Store_to_push(node);
893 /* transform Load->IncSP combinations to Pop where possible */
894 peephole_Load_IncSP_to_pop(node);
896 if (arch_get_irn_register(node) != esp)
899 /* replace IncSP -4 by Pop freereg when possible */
900 offset = be_get_IncSP_offset(node);
901 if ((offset != -8 || ia32_cg_config.use_add_esp_8) &&
902 (offset != -4 || ia32_cg_config.use_add_esp_4) &&
903 (offset != +4 || ia32_cg_config.use_sub_esp_4) &&
904 (offset != +8 || ia32_cg_config.use_sub_esp_8))
908 /* we need a free register for pop */
909 reg = get_free_gp_reg(get_irn_irg(node));
913 dbgi = get_irn_dbg_info(node);
914 block = get_nodes_block(node);
915 stack = be_get_IncSP_pred(node);
917 stack = create_pop(dbgi, block, stack, node, reg);
920 stack = create_pop(dbgi, block, stack, node, reg);
923 dbgi = get_irn_dbg_info(node);
924 block = get_nodes_block(node);
925 stack = be_get_IncSP_pred(node);
926 stack = new_bd_ia32_PushEax(dbgi, block, stack);
927 arch_set_irn_register(stack, esp);
928 sched_add_before(node, stack);
931 stack = new_bd_ia32_PushEax(dbgi, block, stack);
932 arch_set_irn_register(stack, esp);
933 sched_add_before(node, stack);
937 be_peephole_exchange(node, stack);
941 * Peephole optimisation for ia32_Const's
943 static void peephole_ia32_Const(ir_node *node)
945 const ia32_immediate_attr_t *attr = get_ia32_immediate_attr_const(node);
946 const arch_register_t *reg;
951 /* try to transform a mov 0, reg to xor reg reg */
952 if (attr->offset != 0 || attr->symconst != NULL)
954 if (ia32_cg_config.use_mov_0)
956 /* xor destroys the flags, so no-one must be using them */
957 if (be_peephole_get_value(CLASS_ia32_flags, REG_FLAGS_EFLAGS) != NULL)
960 reg = arch_get_irn_register(node);
961 assert(be_peephole_get_reg_value(reg) == NULL);
963 /* create xor(produceval, produceval) */
964 block = get_nodes_block(node);
965 dbgi = get_irn_dbg_info(node);
966 xorn = new_bd_ia32_Xor0(dbgi, block);
967 arch_set_irn_register(xorn, reg);
969 sched_add_before(node, xorn);
971 copy_mark(node, xorn);
972 be_peephole_exchange(node, xorn);
975 static inline int is_noreg(const ir_node *node)
977 return is_ia32_NoReg_GP(node);
980 ir_node *ia32_immediate_from_long(long val)
982 ir_graph *irg = current_ir_graph;
983 ir_node *start_block = get_irg_start_block(irg);
985 = new_bd_ia32_Immediate(NULL, start_block, NULL, 0, 0, val);
986 arch_set_irn_register(immediate, &ia32_registers[REG_GP_NOREG]);
991 static ir_node *create_immediate_from_am(const ir_node *node)
993 ir_node *block = get_nodes_block(node);
994 int offset = get_ia32_am_offs_int(node);
995 int sc_sign = is_ia32_am_sc_sign(node);
996 const ia32_attr_t *attr = get_ia32_attr_const(node);
997 int sc_no_pic_adjust = attr->data.am_sc_no_pic_adjust;
998 ir_entity *entity = get_ia32_am_sc(node);
1001 res = new_bd_ia32_Immediate(NULL, block, entity, sc_sign, sc_no_pic_adjust,
1003 arch_set_irn_register(res, &ia32_registers[REG_GP_NOREG]);
1007 static int is_am_one(const ir_node *node)
1009 int offset = get_ia32_am_offs_int(node);
1010 ir_entity *entity = get_ia32_am_sc(node);
1012 return offset == 1 && entity == NULL;
1015 static int is_am_minus_one(const ir_node *node)
1017 int offset = get_ia32_am_offs_int(node);
1018 ir_entity *entity = get_ia32_am_sc(node);
1020 return offset == -1 && entity == NULL;
1024 * Transforms a LEA into an Add or SHL if possible.
1026 static void peephole_ia32_Lea(ir_node *node)
1031 const arch_register_t *base_reg;
1032 const arch_register_t *index_reg;
1033 const arch_register_t *out_reg;
1044 assert(is_ia32_Lea(node));
1046 /* we can only do this if it is allowed to clobber the flags */
1047 if (be_peephole_get_value(CLASS_ia32_flags, REG_FLAGS_EFLAGS) != NULL)
1050 base = get_irn_n(node, n_ia32_Lea_base);
1051 index = get_irn_n(node, n_ia32_Lea_index);
1053 if (is_noreg(base)) {
1057 base_reg = arch_get_irn_register(base);
1059 if (is_noreg(index)) {
1063 index_reg = arch_get_irn_register(index);
1066 if (base == NULL && index == NULL) {
1067 /* we shouldn't construct these in the first place... */
1068 #ifdef DEBUG_libfirm
1069 ir_fprintf(stderr, "Optimisation warning: found immediate only lea\n");
1074 out_reg = arch_get_irn_register(node);
1075 scale = get_ia32_am_scale(node);
1076 assert(!is_ia32_need_stackent(node) || get_ia32_frame_ent(node) != NULL);
1077 /* check if we have immediates values (frame entities should already be
1078 * expressed in the offsets) */
1079 if (get_ia32_am_offs_int(node) != 0 || get_ia32_am_sc(node) != NULL) {
1085 /* we can transform leas where the out register is the same as either the
1086 * base or index register back to an Add or Shl */
1087 if (out_reg == base_reg) {
1088 if (index == NULL) {
1089 #ifdef DEBUG_libfirm
1090 if (!has_immediates) {
1091 ir_fprintf(stderr, "Optimisation warning: found lea which is "
1096 goto make_add_immediate;
1098 if (scale == 0 && !has_immediates) {
1103 /* can't create an add */
1105 } else if (out_reg == index_reg) {
1107 if (has_immediates && scale == 0) {
1109 goto make_add_immediate;
1110 } else if (!has_immediates && scale > 0) {
1112 op2 = ia32_immediate_from_long(scale);
1114 } else if (!has_immediates) {
1115 #ifdef DEBUG_libfirm
1116 ir_fprintf(stderr, "Optimisation warning: found lea which is "
1120 } else if (scale == 0 && !has_immediates) {
1125 /* can't create an add */
1128 /* can't create an add */
1133 if (ia32_cg_config.use_incdec) {
1134 if (is_am_one(node)) {
1135 dbgi = get_irn_dbg_info(node);
1136 block = get_nodes_block(node);
1137 res = new_bd_ia32_Inc(dbgi, block, op1);
1138 arch_set_irn_register(res, out_reg);
1141 if (is_am_minus_one(node)) {
1142 dbgi = get_irn_dbg_info(node);
1143 block = get_nodes_block(node);
1144 res = new_bd_ia32_Dec(dbgi, block, op1);
1145 arch_set_irn_register(res, out_reg);
1149 op2 = create_immediate_from_am(node);
1152 dbgi = get_irn_dbg_info(node);
1153 block = get_nodes_block(node);
1154 irg = get_irn_irg(node);
1155 noreg = ia32_new_NoReg_gp(irg);
1156 nomem = new_r_NoMem(irg);
1157 res = new_bd_ia32_Add(dbgi, block, noreg, noreg, nomem, op1, op2);
1158 arch_set_irn_register(res, out_reg);
1159 set_ia32_commutative(res);
1163 dbgi = get_irn_dbg_info(node);
1164 block = get_nodes_block(node);
1165 irg = get_irn_irg(node);
1166 noreg = ia32_new_NoReg_gp(irg);
1167 nomem = new_r_NoMem(irg);
1168 res = new_bd_ia32_Shl(dbgi, block, op1, op2);
1169 arch_set_irn_register(res, out_reg);
1173 SET_IA32_ORIG_NODE(res, node);
1175 /* add new ADD/SHL to schedule */
1176 DBG_OPT_LEA2ADD(node, res);
1178 /* exchange the Add and the LEA */
1179 sched_add_before(node, res);
1180 copy_mark(node, res);
1181 be_peephole_exchange(node, res);
1185 * Split a Imul mem, imm into a Load mem and Imul reg, imm if possible.
1187 static void peephole_ia32_Imul_split(ir_node *imul)
1189 const ir_node *right = get_irn_n(imul, n_ia32_IMul_right);
1190 const arch_register_t *reg;
1193 if (!is_ia32_Immediate(right) || get_ia32_op_type(imul) != ia32_AddrModeS) {
1194 /* no memory, imm form ignore */
1197 /* we need a free register */
1198 reg = get_free_gp_reg(get_irn_irg(imul));
1202 /* fine, we can rebuild it */
1203 res = ia32_turn_back_am(imul);
1204 arch_set_irn_register(res, reg);
1208 * Replace xorps r,r and xorpd r,r by pxor r,r
1210 static void peephole_ia32_xZero(ir_node *xorn)
1212 set_irn_op(xorn, op_ia32_xPzero);
1216 * Replace 16bit sign extension from ax to eax by shorter cwtl
1218 static void peephole_ia32_Conv_I2I(ir_node *node)
1220 const arch_register_t *eax = &ia32_registers[REG_EAX];
1221 ir_mode *smaller_mode = get_ia32_ls_mode(node);
1222 ir_node *val = get_irn_n(node, n_ia32_Conv_I2I_val);
1227 if (get_mode_size_bits(smaller_mode) != 16 ||
1228 !mode_is_signed(smaller_mode) ||
1229 eax != arch_get_irn_register(val) ||
1230 eax != arch_irn_get_register(node, pn_ia32_Conv_I2I_res))
1233 dbgi = get_irn_dbg_info(node);
1234 block = get_nodes_block(node);
1235 cwtl = new_bd_ia32_Cwtl(dbgi, block, val);
1236 arch_set_irn_register(cwtl, eax);
1237 sched_add_before(node, cwtl);
1238 be_peephole_exchange(node, cwtl);
1242 * Register a peephole optimisation function.
1244 static void register_peephole_optimisation(ir_op *op, peephole_opt_func func)
1246 assert(op->ops.generic == NULL);
1247 op->ops.generic = (op_func)func;
1250 /* Perform peephole-optimizations. */
1251 void ia32_peephole_optimization(ir_graph *irg)
1253 /* register peephole optimisations */
1254 clear_irp_opcodes_generic_func();
1255 register_peephole_optimisation(op_ia32_Const, peephole_ia32_Const);
1256 register_peephole_optimisation(op_be_IncSP, peephole_be_IncSP);
1257 register_peephole_optimisation(op_ia32_Lea, peephole_ia32_Lea);
1258 register_peephole_optimisation(op_ia32_Cmp, peephole_ia32_Cmp);
1259 register_peephole_optimisation(op_ia32_Cmp8Bit, peephole_ia32_Cmp);
1260 register_peephole_optimisation(op_ia32_Test, peephole_ia32_Test);
1261 register_peephole_optimisation(op_ia32_Test8Bit, peephole_ia32_Test);
1262 register_peephole_optimisation(op_be_Return, peephole_ia32_Return);
1263 if (! ia32_cg_config.use_imul_mem_imm32)
1264 register_peephole_optimisation(op_ia32_IMul, peephole_ia32_Imul_split);
1265 if (ia32_cg_config.use_pxor)
1266 register_peephole_optimisation(op_ia32_xZero, peephole_ia32_xZero);
1267 if (ia32_cg_config.use_short_sex_eax)
1268 register_peephole_optimisation(op_ia32_Conv_I2I, peephole_ia32_Conv_I2I);
1270 be_peephole_opt(irg);
1274 * Removes node from schedule if it is not used anymore. If irn is a mode_T node
1275 * all it's Projs are removed as well.
1276 * @param irn The irn to be removed from schedule
1278 static inline void try_kill(ir_node *node)
1280 if (get_irn_mode(node) == mode_T) {
1281 const ir_edge_t *edge, *next;
1282 foreach_out_edge_safe(node, edge, next) {
1283 ir_node *proj = get_edge_src_irn(edge);
1288 if (get_irn_n_edges(node) != 0)
1291 if (sched_is_scheduled(node)) {
1298 static void optimize_conv_store(ir_node *node)
1303 ir_mode *store_mode;
1305 if (!is_ia32_Store(node) && !is_ia32_Store8Bit(node))
1308 assert((int)n_ia32_Store_val == (int)n_ia32_Store8Bit_val);
1309 pred_proj = get_irn_n(node, n_ia32_Store_val);
1310 if (is_Proj(pred_proj)) {
1311 pred = get_Proj_pred(pred_proj);
1315 if (!is_ia32_Conv_I2I(pred) && !is_ia32_Conv_I2I8Bit(pred))
1317 if (get_ia32_op_type(pred) != ia32_Normal)
1320 /* the store only stores the lower bits, so we only need the conv
1321 * it it shrinks the mode */
1322 conv_mode = get_ia32_ls_mode(pred);
1323 store_mode = get_ia32_ls_mode(node);
1324 if (get_mode_size_bits(conv_mode) < get_mode_size_bits(store_mode))
1327 set_irn_n(node, n_ia32_Store_val, get_irn_n(pred, n_ia32_Conv_I2I_val));
1328 if (get_irn_n_edges(pred_proj) == 0) {
1329 kill_node(pred_proj);
1330 if (pred != pred_proj)
1335 static void optimize_load_conv(ir_node *node)
1337 ir_node *pred, *predpred;
1341 if (!is_ia32_Conv_I2I(node) && !is_ia32_Conv_I2I8Bit(node))
1344 assert((int)n_ia32_Conv_I2I_val == (int)n_ia32_Conv_I2I8Bit_val);
1345 pred = get_irn_n(node, n_ia32_Conv_I2I_val);
1349 predpred = get_Proj_pred(pred);
1350 if (!is_ia32_Load(predpred))
1353 /* the load is sign extending the upper bits, so we only need the conv
1354 * if it shrinks the mode */
1355 load_mode = get_ia32_ls_mode(predpred);
1356 conv_mode = get_ia32_ls_mode(node);
1357 if (get_mode_size_bits(conv_mode) < get_mode_size_bits(load_mode))
1360 if (get_mode_sign(conv_mode) != get_mode_sign(load_mode)) {
1361 /* change the load if it has only 1 user */
1362 if (get_irn_n_edges(pred) == 1) {
1364 if (get_mode_sign(conv_mode)) {
1365 newmode = find_signed_mode(load_mode);
1367 newmode = find_unsigned_mode(load_mode);
1369 assert(newmode != NULL);
1370 set_ia32_ls_mode(predpred, newmode);
1372 /* otherwise we have to keep the conv */
1378 exchange(node, pred);
1381 static void optimize_conv_conv(ir_node *node)
1383 ir_node *pred_proj, *pred, *result_conv;
1384 ir_mode *pred_mode, *conv_mode;
1388 if (!is_ia32_Conv_I2I(node) && !is_ia32_Conv_I2I8Bit(node))
1391 assert((int)n_ia32_Conv_I2I_val == (int)n_ia32_Conv_I2I8Bit_val);
1392 pred_proj = get_irn_n(node, n_ia32_Conv_I2I_val);
1393 if (is_Proj(pred_proj))
1394 pred = get_Proj_pred(pred_proj);
1398 if (!is_ia32_Conv_I2I(pred) && !is_ia32_Conv_I2I8Bit(pred))
1401 /* we know that after a conv, the upper bits are sign extended
1402 * so we only need the 2nd conv if it shrinks the mode */
1403 conv_mode = get_ia32_ls_mode(node);
1404 conv_mode_bits = get_mode_size_bits(conv_mode);
1405 pred_mode = get_ia32_ls_mode(pred);
1406 pred_mode_bits = get_mode_size_bits(pred_mode);
1408 if (conv_mode_bits == pred_mode_bits
1409 && get_mode_sign(conv_mode) == get_mode_sign(pred_mode)) {
1410 result_conv = pred_proj;
1411 } else if (conv_mode_bits <= pred_mode_bits) {
1412 /* if 2nd conv is smaller then first conv, then we can always take the
1414 if (get_irn_n_edges(pred_proj) == 1) {
1415 result_conv = pred_proj;
1416 set_ia32_ls_mode(pred, conv_mode);
1418 /* Argh:We must change the opcode to 8bit AND copy the register constraints */
1419 if (get_mode_size_bits(conv_mode) == 8) {
1420 set_irn_op(pred, op_ia32_Conv_I2I8Bit);
1421 arch_set_in_register_reqs(pred,
1422 arch_get_in_register_reqs(node));
1425 /* we don't want to end up with 2 loads, so we better do nothing */
1426 if (get_irn_mode(pred) == mode_T) {
1430 result_conv = exact_copy(pred);
1431 set_ia32_ls_mode(result_conv, conv_mode);
1433 /* Argh:We must change the opcode to 8bit AND copy the register constraints */
1434 if (get_mode_size_bits(conv_mode) == 8) {
1435 set_irn_op(result_conv, op_ia32_Conv_I2I8Bit);
1436 arch_set_in_register_reqs(result_conv,
1437 arch_get_in_register_reqs(node));
1441 /* if both convs have the same sign, then we can take the smaller one */
1442 if (get_mode_sign(conv_mode) == get_mode_sign(pred_mode)) {
1443 result_conv = pred_proj;
1445 /* no optimisation possible if smaller conv is sign-extend */
1446 if (mode_is_signed(pred_mode)) {
1449 /* we can take the smaller conv if it is unsigned */
1450 result_conv = pred_proj;
1454 /* Some user (like Phis) won't be happy if we change the mode. */
1455 set_irn_mode(result_conv, get_irn_mode(node));
1458 exchange(node, result_conv);
1460 if (get_irn_n_edges(pred_proj) == 0) {
1461 kill_node(pred_proj);
1462 if (pred != pred_proj)
1465 optimize_conv_conv(result_conv);
1468 static void optimize_node(ir_node *node, void *env)
1472 optimize_load_conv(node);
1473 optimize_conv_store(node);
1474 optimize_conv_conv(node);
1478 * Performs conv and address mode optimization.
1480 void ia32_optimize_graph(ir_graph *irg)
1482 irg_walk_blkwise_graph(irg, NULL, optimize_node, NULL);
1485 void ia32_init_optimize(void)
1487 FIRM_DBG_REGISTER(dbg, "firm.be.ia32.optimize");