+#define INST_IGNORES_CFLAGS(opcode) (!(((opcode) == OP_ADC) || ((opcode) == OP_ADC_IMM) || ((opcode) == OP_IADC) || ((opcode) == OP_IADC_IMM) || ((opcode) == OP_SBB) || ((opcode) == OP_SBB_IMM) || ((opcode) == OP_ISBB) || ((opcode) == OP_ISBB_IMM)))
+
+/*
+ * peephole_pass_1:
+ *
+ * Perform peephole opts which should/can be performed before local regalloc
+ */
+static void
+peephole_pass_1 (MonoCompile *cfg, MonoBasicBlock *bb)
+{
+ MonoInst *ins, *last_ins = NULL;
+ ins = bb->code;
+
+ while (ins) {
+
+ switch (ins->opcode) {
+ case OP_ADD_IMM:
+ case OP_IADD_IMM:
+ case OP_LADD_IMM:
+ if ((ins->sreg1 < MONO_MAX_IREGS) && (ins->dreg >= MONO_MAX_IREGS) && (ins->inst_imm > 0)) {
+ /*
+ * X86_LEA is like ADD, but doesn't have the
+ * sreg1==dreg restriction. inst_imm > 0 is needed since LEA sign-extends
+ * its operand to 64 bit.
+ */
+ ins->opcode = OP_X86_LEA_MEMBASE;
+ ins->inst_basereg = ins->sreg1;
+ /* Fall through */
+ }
+ else
+ break;
+ case CEE_XOR:
+ if ((ins->sreg1 == ins->sreg2) && (ins->sreg1 == ins->dreg)) {
+ MonoInst *ins2;
+
+ /*
+ * Replace STORE_MEMBASE_IMM 0 with STORE_MEMBASE_REG since
+ * the latter has length 2-3 instead of 6 (reverse constant
+ * propagation). These instruction sequences are very common
+ * in the initlocals bblock.
+ */
+ for (ins2 = ins->next; ins2; ins2 = ins2->next) {
+ if (((ins2->opcode == OP_STORE_MEMBASE_IMM) || (ins2->opcode == OP_STOREI4_MEMBASE_IMM) || (ins2->opcode == OP_STOREI8_MEMBASE_IMM) || (ins2->opcode == OP_STORE_MEMBASE_IMM)) && (ins2->inst_imm == 0)) {
+ ins2->opcode = store_membase_imm_to_store_membase_reg (ins2->opcode);
+ ins2->sreg1 = ins->dreg;
+ } else if ((ins2->opcode == OP_STOREI1_MEMBASE_IMM) || (ins2->opcode == OP_STOREI2_MEMBASE_IMM) || (ins2->opcode == OP_STOREI8_MEMBASE_REG) || (ins2->opcode == OP_STORE_MEMBASE_REG)) {
+ /* Continue */
+ } else if (((ins2->opcode == OP_ICONST) || (ins2->opcode == OP_I8CONST)) && (ins2->dreg == ins->dreg) && (ins2->inst_c0 == 0)) {
+ NULLIFY_INS (ins2);
+ /* Continue */
+ } else {
+ break;
+ }
+ }
+ }
+ break;
+ case OP_COMPARE_IMM:
+ /* OP_COMPARE_IMM (reg, 0)
+ * -->
+ * OP_AMD64_TEST_NULL (reg)
+ */
+ if (!ins->inst_imm)
+ ins->opcode = OP_AMD64_TEST_NULL;
+ break;
+ case OP_ICOMPARE_IMM:
+ if (!ins->inst_imm)
+ ins->opcode = OP_X86_TEST_NULL;
+ break;
+ case OP_AMD64_ICOMPARE_MEMBASE_IMM:
+ /*
+ * OP_STORE_MEMBASE_REG reg, offset(basereg)
+ * OP_X86_COMPARE_MEMBASE_IMM offset(basereg), imm
+ * -->
+ * OP_STORE_MEMBASE_REG reg, offset(basereg)
+ * OP_COMPARE_IMM reg, imm
+ *
+ * Note: if imm = 0 then OP_COMPARE_IMM replaced with OP_X86_TEST_NULL
+ */
+ if (last_ins && (last_ins->opcode == OP_STOREI4_MEMBASE_REG) &&
+ ins->inst_basereg == last_ins->inst_destbasereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+ ins->opcode = OP_ICOMPARE_IMM;
+ ins->sreg1 = last_ins->sreg1;
+
+ /* check if we can remove cmp reg,0 with test null */
+ if (!ins->inst_imm)
+ ins->opcode = OP_X86_TEST_NULL;
+ }
+
+ break;
+ case OP_LOAD_MEMBASE:
+ case OP_LOADI4_MEMBASE:
+ /*
+ * Note: if reg1 = reg2 the load op is removed
+ *
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_LOAD_MEMBASE offset(basereg), reg2
+ * -->
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_MOVE reg1, reg2
+ */
+ if (last_ins && (last_ins->opcode == OP_STOREI4_MEMBASE_REG
+ || last_ins->opcode == OP_STORE_MEMBASE_REG) &&
+ ins->inst_basereg == last_ins->inst_destbasereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+ if (ins->dreg == last_ins->sreg1) {
+ last_ins->next = ins->next;
+ ins = ins->next;
+ continue;
+ } else {
+ //static int c = 0; printf ("MATCHX %s %d\n", cfg->method->name,c++);
+ ins->opcode = OP_MOVE;
+ ins->sreg1 = last_ins->sreg1;
+ }
+
+ /*
+ * Note: reg1 must be different from the basereg in the second load
+ * Note: if reg1 = reg2 is equal then second load is removed
+ *
+ * OP_LOAD_MEMBASE offset(basereg), reg1
+ * OP_LOAD_MEMBASE offset(basereg), reg2
+ * -->
+ * OP_LOAD_MEMBASE offset(basereg), reg1
+ * OP_MOVE reg1, reg2
+ */
+ } if (last_ins && (last_ins->opcode == OP_LOADI4_MEMBASE
+ || last_ins->opcode == OP_LOAD_MEMBASE) &&
+ ins->inst_basereg != last_ins->dreg &&
+ ins->inst_basereg == last_ins->inst_basereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+
+ if (ins->dreg == last_ins->dreg) {
+ last_ins->next = ins->next;
+ ins = ins->next;
+ continue;
+ } else {
+ ins->opcode = OP_MOVE;
+ ins->sreg1 = last_ins->dreg;
+ }
+
+ //g_assert_not_reached ();
+
+#if 0
+ /*
+ * OP_STORE_MEMBASE_IMM imm, offset(basereg)
+ * OP_LOAD_MEMBASE offset(basereg), reg
+ * -->
+ * OP_STORE_MEMBASE_IMM imm, offset(basereg)
+ * OP_ICONST reg, imm
+ */
+ } else if (last_ins && (last_ins->opcode == OP_STOREI4_MEMBASE_IMM
+ || last_ins->opcode == OP_STORE_MEMBASE_IMM) &&
+ ins->inst_basereg == last_ins->inst_destbasereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+ //static int c = 0; printf ("MATCHX %s %d\n", cfg->method->name,c++);
+ ins->opcode = OP_ICONST;
+ ins->inst_c0 = last_ins->inst_imm;
+ g_assert_not_reached (); // check this rule
+#endif
+ }
+ break;
+ case OP_LOADI1_MEMBASE:
+ /*
+ * Note: if reg1 = reg2 the load op is removed
+ *
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_LOAD_MEMBASE offset(basereg), reg2
+ * -->
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_MOVE reg1, reg2
+ */
+ if (last_ins && (last_ins->opcode == OP_STOREI1_MEMBASE_REG) &&
+ ins->inst_basereg == last_ins->inst_destbasereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+ if (ins->dreg == last_ins->sreg1) {
+ last_ins->next = ins->next;
+ ins = ins->next;
+ continue;
+ } else {
+ //static int c = 0; printf ("MATCHX %s %d\n", cfg->method->name,c++);
+ ins->opcode = OP_MOVE;
+ ins->sreg1 = last_ins->sreg1;
+ }
+ }
+ break;
+ case OP_LOADI2_MEMBASE:
+ /*
+ * Note: if reg1 = reg2 the load op is removed
+ *
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_LOAD_MEMBASE offset(basereg), reg2
+ * -->
+ * OP_STORE_MEMBASE_REG reg1, offset(basereg)
+ * OP_MOVE reg1, reg2
+ */
+ if (last_ins && (last_ins->opcode == OP_STOREI2_MEMBASE_REG) &&
+ ins->inst_basereg == last_ins->inst_destbasereg &&
+ ins->inst_offset == last_ins->inst_offset) {
+ if (ins->dreg == last_ins->sreg1) {
+ last_ins->next = ins->next;
+ ins = ins->next;
+ continue;
+ } else {
+ //static int c = 0; printf ("MATCHX %s %d\n", cfg->method->name,c++);
+ ins->opcode = OP_MOVE;
+ ins->sreg1 = last_ins->sreg1;
+ }
+ }
+ break;
+ case CEE_CONV_I4:
+ case CEE_CONV_U4:
+ case OP_MOVE:
+ case OP_FMOVE:
+ /*
+ * Removes:
+ *
+ * OP_MOVE reg, reg
+ */
+ if (ins->dreg == ins->sreg1) {
+ if (last_ins)
+ last_ins->next = ins->next;
+ else
+ bb->code = ins->next;
+ ins = ins->next;
+ continue;
+ }
+ /*
+ * Removes:
+ *
+ * OP_MOVE sreg, dreg
+ * OP_MOVE dreg, sreg
+ */
+ if (last_ins && last_ins->opcode == OP_MOVE &&
+ ins->sreg1 == last_ins->dreg &&
+ ins->dreg == last_ins->sreg1) {
+ last_ins->next = ins->next;
+ ins = ins->next;
+ continue;
+ }
+ break;
+ }
+ last_ins = ins;
+ ins = ins->next;
+ }
+ bb->last_ins = last_ins;
+}