+/**
+ * Possible transformations for creating a Setcc.
+ */
+enum setcc_transform_insn {
+ SETCC_TR_ADD,
+ SETCC_TR_ADDxx,
+ SETCC_TR_LEA,
+ SETCC_TR_LEAxx,
+ SETCC_TR_SHL,
+ SETCC_TR_NEG,
+ SETCC_TR_NOT,
+ SETCC_TR_AND,
+ SETCC_TR_SET,
+ SETCC_TR_SBB,
+};
+
+typedef struct setcc_transform {
+ unsigned num_steps;
+ unsigned permutate_cmp_ins;
+ pn_Cmp pnc;
+ struct {
+ enum setcc_transform_insn transform;
+ long val;
+ int scale;
+ } steps[4];
+} setcc_transform_t;
+
+/**
+ * Setcc can only handle 0 and 1 result.
+ * Find a transformation that creates 0 and 1 from
+ * tv_t and tv_f.
+ */
+static void find_const_transform(pn_Cmp pnc, tarval *t, tarval *f, setcc_transform_t *res, int can_permutate)
+{
+ unsigned step = 0;
+
+ res->num_steps = 0;
+ res->permutate_cmp_ins = 0;
+
+ if (tarval_is_null(t)) {
+ tarval *tmp = t;
+ t = f;
+ f = tmp;
+ pnc = ia32_get_negated_pnc(pnc);
+ } else if (tarval_cmp(t, f) == pn_Cmp_Lt) {
+ // now, t is the bigger one
+ tarval *tmp = t;
+ t = f;
+ f = tmp;
+ pnc = ia32_get_negated_pnc(pnc);
+ }
+ res->pnc = pnc;
+
+ if (tarval_is_one(t)) {
+ res->steps[step].transform = SETCC_TR_SET;
+ res->num_steps = ++step;
+ return;
+ }
+
+ if (! tarval_is_null(f)) {
+ tarval *t_sub = tarval_sub(t, f, NULL);
+
+ t = t_sub;
+ res->steps[step].transform = SETCC_TR_ADD;
+
+ if (t == tarval_bad)
+ panic("constant subtract failed");
+ if (! tarval_is_long(f))
+ panic("tarval is not long");
+
+ res->steps[step].val = get_tarval_long(f);
+ ++step;
+ f = tarval_sub(f, f, NULL);
+ assert(tarval_is_null(f));
+ }
+
+ if (tarval_is_minus_one(t)) {
+ if (pnc == (pn_Cmp_Lt | ia32_pn_Cmp_unsigned)) {
+ res->steps[step].transform = SETCC_TR_SBB;
+ res->num_steps = ++step;
+ } else {
+ res->steps[step].transform = SETCC_TR_NEG;
+ ++step;
+ res->steps[step].transform = SETCC_TR_SET;
+ res->num_steps = ++step;
+ }
+ return;
+ }
+ if (tarval_is_long(t)) {
+ ir_mode *mode = get_tarval_mode(t);
+ long v = get_tarval_long(t);
+
+ if (pnc & ia32_pn_Cmp_unsigned) {
+ if (pnc == (pn_Cmp_Lt | ia32_pn_Cmp_unsigned)) {
+ res->steps[step].transform = SETCC_TR_AND;
+ res->steps[step].val = v;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_SBB;
+ res->num_steps = ++step;
+ return;
+ } else if (pnc == (pn_Cmp_Ge | ia32_pn_Cmp_unsigned)) {
+ res->steps[step].transform = SETCC_TR_AND;
+ res->steps[step].val = v;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_NOT;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_SBB;
+ res->num_steps = ++step;
+ return;
+ } else if (can_permutate && pnc == (pn_Cmp_Gt | ia32_pn_Cmp_unsigned)) {
+ res->permutate_cmp_ins ^= 1;
+
+ res->steps[step].transform = SETCC_TR_NOT;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_AND;
+ res->steps[step].val = v;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_SBB;
+ res->num_steps = ++step;
+ return;
+ } else if (can_permutate && pnc == (pn_Cmp_Le | ia32_pn_Cmp_unsigned)) {
+ res->permutate_cmp_ins ^= 1;
+
+ res->steps[step].transform = SETCC_TR_AND;
+ res->steps[step].val = v;
+ ++step;
+
+ res->steps[step].transform = SETCC_TR_SBB;
+ res->num_steps = ++step;
+ return;
+ }
+ }
+
+ res->steps[step].val = 0;
+ switch (v) {
+ case 9:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = SETCC_TR_LEAxx;
+ res->steps[step].scale = 3; /* (a << 3) + a */
+ break;
+ case 8:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = res->steps[step].val == 0 ? SETCC_TR_SHL : SETCC_TR_LEA;
+ res->steps[step].scale = 3; /* (a << 3) */
+ break;
+ case 5:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = SETCC_TR_LEAxx;
+ res->steps[step].scale = 2; /* (a << 2) + a */
+ break;
+ case 4:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = res->steps[step].val == 0 ? SETCC_TR_SHL : SETCC_TR_LEA;
+ res->steps[step].scale = 2; /* (a << 2) */
+ break;
+ case 3:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = SETCC_TR_LEAxx;
+ res->steps[step].scale = 1; /* (a << 1) + a */
+ break;
+ case 2:
+ if (step > 0 && res->steps[step - 1].transform == SETCC_TR_ADD)
+ --step;
+ res->steps[step].transform = res->steps[step].val == 0 ? SETCC_TR_SHL : SETCC_TR_LEA;
+ res->steps[step].scale = 1; /* (a << 1) */
+ break;
+ case 1:
+ res->num_steps = step;
+ return;
+ default:
+ if (! tarval_is_single_bit(t)) {
+ res->steps[step].transform = SETCC_TR_AND;
+ res->steps[step].val = v;
+ ++step;
+ res->steps[step].transform = SETCC_TR_NEG;
+ } else {
+ int v = get_tarval_lowest_bit(t);
+ assert(v >= 0);
+
+ res->steps[step].transform = SETCC_TR_SHL;
+ res->steps[step].scale = v;
+ }
+ }
+ ++step;
+ res->steps[step].transform = SETCC_TR_SET;
+ res->num_steps = ++step;
+ return;
+ }
+ panic("tarval is not long");
+}
+