static const arch_env_t *arch_env;
static ia32_code_gen_t *cg;
-#if 0
-static void peephole_ia32_Store_IncSP_to_push(ir_node *node)
-{
- ir_node *base = get_irn_n(node, n_ia32_Store_base);
- ir_node *index = get_irn_n(node, n_ia32_Store_index);
- ir_node *mem = get_irn_n(node, n_ia32_Store_mem);
- ir_node *incsp = base;
- ir_node *val;
- ir_node *noreg;
- ir_graph *irg;
- ir_node *block;
- dbg_info *dbgi;
- ir_mode *mode;
- ir_node *push;
- ir_node *proj;
- int offset;
- int node_offset;
-
- /* nomem inidicates the store doesn't alias with anything else */
- if(!is_NoMem(mem))
- return;
-
- /* find an IncSP in front of us, we might have to skip barriers for this */
- while(is_Proj(incsp)) {
- ir_node *proj_pred = get_Proj_pred(incsp);
- if(!be_is_Barrier(proj_pred))
- return;
- incsp = get_irn_n(proj_pred, get_Proj_proj(incsp));
- }
- if(!be_is_IncSP(incsp))
- return;
-
- be_peephole_IncSP_IncSP(incsp);
-
- /* must be in the same block */
- if(get_nodes_block(incsp) != get_nodes_block(node))
- return;
-
- if(!is_ia32_NoReg_GP(index) || get_ia32_am_sc(node) != NULL) {
- panic("Invalid storeAM found (%+F)", node);
- }
-
- /* we should be the store to the end of the stackspace */
- offset = be_get_IncSP_offset(incsp);
- mode = get_ia32_ls_mode(node);
- node_offset = get_ia32_am_offs_int(node);
- if(node_offset != offset - get_mode_size_bytes(mode))
- return;
-
- /* we can use a push instead of the store */
- irg = current_ir_graph;
- block = get_nodes_block(node);
- dbgi = get_irn_dbg_info(node);
- noreg = ia32_new_NoReg_gp(cg);
- base = be_get_IncSP_pred(incsp);
- val = get_irn_n(node, n_ia32_Store_val);
- push = new_rd_ia32_Push(dbgi, irg, block, noreg, noreg, mem, val, base);
-
- proj = new_r_Proj(irg, block, push, mode_M, pn_ia32_Push_M);
-
- be_set_IncSP_offset(incsp, offset - get_mode_size_bytes(mode));
-
- sched_add_before(node, push);
- sched_remove(node);
-
- be_peephole_before_exchange(node, proj);
- exchange(node, proj);
- be_peephole_after_exchange(proj);
-}
-
-static void peephole_ia32_Store(ir_node *node)
-{
- peephole_ia32_Store_IncSP_to_push(node);
-}
-#endif
-
+/**
+ * Returns non-zero if the given node produces
+ * a zero flag.
+ *
+ * @param node the node to check
+ * @param pn if >= 0, the projection number of the used result
+ */
static int produces_zero_flag(ir_node *node, int pn)
{
ir_node *count;
const ia32_immediate_attr_t *imm_attr;
- if(!is_ia32_irn(node))
+ if (!is_ia32_irn(node))
return 0;
- if(pn >= 0) {
- if(pn != pn_ia32_res)
+ if (pn >= 0) {
+ if (pn != pn_ia32_res)
return 0;
}
- switch(get_ia32_irn_opcode(node)) {
+ switch (get_ia32_irn_opcode(node)) {
case iro_ia32_Add:
case iro_ia32_Adc:
case iro_ia32_And:
assert(n_ia32_ShlD_count == n_ia32_ShrD_count);
assert(n_ia32_Shl_count == n_ia32_Shr_count
&& n_ia32_Shl_count == n_ia32_Sar_count);
- if(is_ia32_ShlD(node) || is_ia32_ShrD(node)) {
+ if (is_ia32_ShlD(node) || is_ia32_ShrD(node)) {
count = get_irn_n(node, n_ia32_ShlD_count);
} else {
count = get_irn_n(node, n_ia32_Shl_count);
}
/* when shift count is zero the flags are not affected, so we can only
* do this for constants != 0 */
- if(!is_ia32_Immediate(count))
+ if (!is_ia32_Immediate(count))
return 0;
imm_attr = get_ia32_immediate_attr_const(count);
- if(imm_attr->symconst != NULL)
+ if (imm_attr->symconst != NULL)
return 0;
- if((imm_attr->offset & 0x1f) == 0)
+ if ((imm_attr->offset & 0x1f) == 0)
return 0;
return 1;
return 0;
}
+/**
+ * If the given node has not mode_T, creates a mode_T version (with a result Proj).
+ *
+ * @param node the node to change
+ *
+ * @return the new mode_T node (if the mode was changed) or node itself
+ */
static ir_node *turn_into_mode_t(ir_node *node)
{
ir_node *block;
return new_node;
}
+/**
+ * Peephole optimization for Test instructions.
+ * We can remove the Test, if a zero flags was produced which is still
+ * live.
+ */
static void peephole_ia32_Test(ir_node *node)
{
- ir_node *left = get_irn_n(node, n_ia32_Test_left);
- ir_node *right = get_irn_n(node, n_ia32_Test_right);
- ir_node *flags_proj;
- ir_node *block;
- ir_mode *flags_mode;
- int pn = -1;
- ir_node *schedpoint;
- const ir_edge_t *edge;
+ ir_node *left = get_irn_n(node, n_ia32_Test_left);
+ ir_node *right = get_irn_n(node, n_ia32_Test_right);
+ ir_node *flags_proj;
+ ir_node *block;
+ ir_mode *flags_mode;
+ int pn = -1;
+ ir_node *schedpoint;
+ const ir_edge_t *edge;
assert(n_ia32_Test_left == n_ia32_Test8Bit_left
&& n_ia32_Test_right == n_ia32_Test8Bit_right);
block = get_nodes_block(node);
- if (get_Block_n_cfgpreds(block) == 1) {
- ir_node *pred = get_Block_cfgpred(block, 0);
-
- if (is_Jmp(pred)) {
- /* The block of the return has only one predecessor,
- which jumps directly to this block.
- This jump will be encoded as a fall through, so we
- ignore it here.
- However, the predecessor might be empty, so it must be
- ensured that empty blocks are gone away ... */
- return;
- }
- }
-
/* check if this return is the first on the block */
sched_foreach_reverse_from(node, irn) {
switch (get_irn_opcode(irn)) {
return;
}
}
- /* yep, return is the first real instruction in this block */
-#if 0
- {
- /* add an rep prefix to the return */
- ir_node *rep = new_rd_ia32_RepPrefix(get_irn_dbg_info(node), current_ir_graph, block);
- keep_alive(rep);
- sched_add_before(node, rep);
- }
-#else
- /* ensure, that the 3 byte return is generated */
+
+ /* ensure, that the 3 byte return is generated
+ * actually the emitter tests again if the block beginning has a label and
+ * isn't just a fallthrough */
be_Return_set_emit_pop(node, 1);
-#endif
}
/* only optimize up to 48 stores behind IncSPs */
#define MAXPUSH_OPTIMIZE 48
/**
- * Tries to create pushs from IncSP,Store combinations.
+ * Tries to create Push's from IncSP, Store combinations.
* The Stores are replaced by Push's, the IncSP is modified
* (possibly into IncSP 0, but not removed).
*/
static void peephole_IncSP_Store_to_push(ir_node *irn)
{
- int i, maxslot, inc_ofs;
- ir_node *node;
- ir_node *stores[MAXPUSH_OPTIMIZE];
- ir_node *block = get_nodes_block(irn);
- ir_graph *irg = cg->irg;
- ir_node *curr_sp;
- ir_mode *spmode = get_irn_mode(irn);
+ int i, maxslot, inc_ofs;
+ ir_node *node;
+ ir_node *stores[MAXPUSH_OPTIMIZE];
+ ir_node *block;
+ ir_graph *irg;
+ ir_node *curr_sp;
+ ir_mode *spmode;
memset(stores, 0, sizeof(stores));
/*
* We first walk the schedule after the IncSP node as long as we find
- * suitable stores that could be transformed to a push.
+ * suitable Stores that could be transformed to a Push.
* We save them into the stores array which is sorted by the frame offset/4
* attached to the node
*/
curr_sp = be_get_IncSP_pred(irn);
- /* walk through the stores and create Pushs for them */
+ /* walk through the Stores and create Pushs for them */
+ block = get_nodes_block(irn);
+ spmode = get_irn_mode(irn);
+ irg = cg->irg;
for (i = 0; i <= maxslot; ++i) {
const arch_register_t *spreg;
ir_node *push;
/* use the memproj now */
exchange(store, mem_proj);
- /* we can remove the store now */
+ /* we can remove the Store now */
sched_remove(store);
inc_ofs -= 4;
be_set_IncSP_pred(irn, curr_sp);
}
+/**
+ * Return true if a mode can be stored in the GP register set
+ */
+static INLINE int mode_needs_gp_reg(ir_mode *mode) {
+ if (mode == mode_fpcw)
+ return 0;
+ if (get_mode_size_bits(mode) > 32)
+ return 0;
+ return mode_is_int(mode) || mode_is_reference(mode) || mode == mode_b;
+}
+
+/**
+ * Tries to create Pops from Load, IncSP combinations.
+ * The Loads are replaced by Pops, the IncSP is modified
+ * (possibly into IncSP 0, but not removed).
+ */
+static void peephole_Load_IncSP_to_pop(ir_node *irn)
+{
+ const arch_register_t *esp = &ia32_gp_regs[REG_ESP];
+ int i, maxslot, inc_ofs, ofs;
+ ir_node *node, *pred_sp, *block;
+ ir_node *loads[MAXPUSH_OPTIMIZE];
+ ir_graph *irg;
+ unsigned regmask = 0;
+ unsigned copymask = ~0;
+
+ memset(loads, 0, sizeof(loads));
+ assert(be_is_IncSP(irn));
+
+ inc_ofs = -be_get_IncSP_offset(irn);
+ if (inc_ofs < 4)
+ return;
+
+ /*
+ * We first walk the schedule before the IncSP node as long as we find
+ * suitable Loads that could be transformed to a Pop.
+ * We save them into the stores array which is sorted by the frame offset/4
+ * attached to the node
+ */
+ maxslot = -1;
+ pred_sp = be_get_IncSP_pred(irn);
+ for (node = sched_prev(irn); !sched_is_end(node); node = sched_prev(node)) {
+ ir_node *mem;
+ int offset;
+ int loadslot;
+ const arch_register_t *sreg, *dreg;
+
+ /* it has to be a Load */
+ if (!is_ia32_Load(node)) {
+ if (be_is_Copy(node)) {
+ if (!mode_needs_gp_reg(get_irn_mode(node))) {
+ /* not a GP copy, ignore */
+ continue;
+ }
+ dreg = arch_get_irn_register(arch_env, node);
+ sreg = arch_get_irn_register(arch_env, be_get_Copy_op(node));
+ if (regmask & copymask & (1 << sreg->index)) {
+ break;
+ }
+ if (regmask & copymask & (1 << dreg->index)) {
+ break;
+ }
+ /* we CAN skip Copies if neither the destination nor the source
+ * is not in our regmask, ie none of our future Pop will overwrite it */
+ regmask |= (1 << dreg->index) | (1 << sreg->index);
+ copymask &= ~((1 << dreg->index) | (1 << sreg->index));
+ continue;
+ }
+ break;
+ }
+
+ /* we can handle only GP loads */
+ if (!mode_needs_gp_reg(get_ia32_ls_mode(node)))
+ continue;
+
+ /* it has to use our predecessor sp value */
+ if (get_irn_n(node, n_ia32_base) != pred_sp) {
+ /* it would be ok if this load does not use a Pop result,
+ * but we do not check this */
+ break;
+ }
+ /* Load has to be attached to Spill-Mem */
+ mem = skip_Proj(get_irn_n(node, n_ia32_mem));
+ if (!is_Phi(mem) && !is_ia32_Store(mem) && !is_ia32_Push(mem))
+ break;
+
+ /* should have NO index */
+ if (get_ia32_am_scale(node) > 0 || !is_ia32_NoReg_GP(get_irn_n(node, n_ia32_index)))
+ break;
+
+ offset = get_ia32_am_offs_int(node);
+ /* we should NEVER access uninitialized stack BELOW the current SP */
+ assert(offset >= 0);
+
+ /* storing at half-slots is bad */
+ if ((offset & 3) != 0)
+ break;
+
+ if (offset < 0 || offset >= MAXPUSH_OPTIMIZE * 4)
+ continue;
+ /* ignore those outside the possible windows */
+ if (offset > inc_ofs - 4)
+ continue;
+ loadslot = offset >> 2;
+
+ /* loading from the same slot twice is bad (and shouldn't happen...) */
+ if (loads[loadslot] != NULL)
+ break;
+
+ dreg = arch_get_irn_register(arch_env, node);
+ if (regmask & (1 << dreg->index)) {
+ /* this register is already used */
+ break;
+ }
+ regmask |= 1 << dreg->index;
+
+ loads[loadslot] = node;
+ if (loadslot > maxslot)
+ maxslot = loadslot;
+ }
+
+ if (maxslot < 0)
+ return;
+
+ /* find the first slot */
+ for (i = maxslot; i >= 0; --i) {
+ ir_node *load = loads[i];
+
+ if (load == NULL)
+ break;
+ }
+
+ ofs = inc_ofs - (maxslot + 1) * 4;
+ inc_ofs = (i+1) * 4;
+
+ /* create a new IncSP if needed */
+ block = get_nodes_block(irn);
+ irg = cg->irg;
+ if (inc_ofs > 0) {
+ pred_sp = be_new_IncSP(esp, irg, block, pred_sp, -inc_ofs, be_get_IncSP_align(irn));
+ sched_add_before(irn, pred_sp);
+ }
+
+ /* walk through the Loads and create Pops for them */
+ for (++i; i <= maxslot; ++i) {
+ ir_node *load = loads[i];
+ ir_node *mem, *pop;
+ const ir_edge_t *edge, *tmp;
+ const arch_register_t *reg;
+
+ mem = get_irn_n(load, n_ia32_mem);
+ reg = arch_get_irn_register(arch_env, load);
+
+ pop = new_rd_ia32_Pop(get_irn_dbg_info(load), irg, block, mem, pred_sp);
+ arch_set_irn_register(arch_env, pop, reg);
+
+ /* create stackpointer Proj */
+ pred_sp = new_r_Proj(irg, block, pop, mode_Iu, pn_ia32_Pop_stack);
+ arch_set_irn_register(arch_env, pred_sp, esp);
+
+ sched_add_before(irn, pop);
+
+ /* rewire now */
+ foreach_out_edge_safe(load, edge, tmp) {
+ ir_node *proj = get_edge_src_irn(edge);
+
+ set_Proj_pred(proj, pop);
+ }
+
+
+ /* we can remove the Load now */
+ sched_remove(load);
+ kill_node(load);
+ }
+ be_set_IncSP_offset(irn, -ofs);
+ be_set_IncSP_pred(irn, pred_sp);
+
+}
+
+
/**
* Find a free GP register if possible, else return NULL.
*/
}
/**
- * Optimize an IncSp by replacing it with push/pop
+ * Optimize an IncSp by replacing it with Push/Pop.
*/
static void peephole_be_IncSP(ir_node *node)
{
int offset;
/* first optimize incsp->incsp combinations */
- be_peephole_IncSP_IncSP(node);
+ node = be_peephole_IncSP_IncSP(node);
/* transform IncSP->Store combinations to Push where possible */
peephole_IncSP_Store_to_push(node);
+ /* transform Load->IncSP combinations to Pop where possible */
+ peephole_Load_IncSP_to_pop(node);
+
if (arch_get_irn_register(arch_env, node) != esp)
return;
/* register peephole optimisations */
clear_irp_opcodes_generic_func();
register_peephole_optimisation(op_ia32_Const, peephole_ia32_Const);
- //register_peephole_optimisation(op_ia32_Store, peephole_ia32_Store);
register_peephole_optimisation(op_be_IncSP, peephole_be_IncSP);
register_peephole_optimisation(op_ia32_Lea, peephole_ia32_Lea);
register_peephole_optimisation(op_ia32_Test, peephole_ia32_Test);
projects / libfirm / blobdiff