tcg/optimize: Split out fold_setcond2

Reduce some code duplication by folding the NE and EQ cases.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/optimize.c

@@ -854,6 +854,75 @@ static bool fold_remainder(OptContext *ctx, TCGOp *op)
     return fold_const2(ctx, op);
 }
 
+static bool fold_setcond2(OptContext *ctx, TCGOp *op)
+{
+    TCGCond cond = op->args[5];
+    int i = do_constant_folding_cond2(&op->args[1], &op->args[3], cond);
+    int inv = 0;
+
+    if (i >= 0) {
+        goto do_setcond_const;
+    }
+
+    switch (cond) {
+    case TCG_COND_LT:
+    case TCG_COND_GE:
+        /*
+         * Simplify LT/GE comparisons vs zero to a single compare
+         * vs the high word of the input.
+         */
+        if (arg_is_const(op->args[3]) && arg_info(op->args[3])->val == 0 &&
+            arg_is_const(op->args[4]) && arg_info(op->args[4])->val == 0) {
+            goto do_setcond_high;
+        }
+        break;
+
+    case TCG_COND_NE:
+        inv = 1;
+        QEMU_FALLTHROUGH;
+    case TCG_COND_EQ:
+        /*
+         * Simplify EQ/NE comparisons where one of the pairs
+         * can be simplified.
+         */
+        i = do_constant_folding_cond(INDEX_op_setcond_i32, op->args[1],
+                                     op->args[3], cond);
+        switch (i ^ inv) {
+        case 0:
+            goto do_setcond_const;
+        case 1:
+            goto do_setcond_high;
+        }
+
+        i = do_constant_folding_cond(INDEX_op_setcond_i32, op->args[2],
+                                     op->args[4], cond);
+        switch (i ^ inv) {
+        case 0:
+            goto do_setcond_const;
+        case 1:
+            op->args[2] = op->args[3];
+            op->args[3] = cond;
+            op->opc = INDEX_op_setcond_i32;
+            break;
+        }
+        break;
+
+    default:
+        break;
+
+    do_setcond_high:
+        op->args[1] = op->args[2];
+        op->args[2] = op->args[4];
+        op->args[3] = cond;
+        op->opc = INDEX_op_setcond_i32;
+        break;
+    }
+    return false;
+
+ do_setcond_const:
+    return tcg_opt_gen_movi(ctx, op, op->args[0], i);
+}
+
 static bool fold_shift(OptContext *ctx, TCGOp *op)
 {
     return fold_const2(ctx, op);
@@ -1653,79 +1722,6 @@ void tcg_optimize(TCGContext *s)
             }
             break;
 
-        case INDEX_op_setcond2_i32:
-            i = do_constant_folding_cond2(&op->args[1], &op->args[3],
-                                          op->args[5]);
-            if (i >= 0) {
-            do_setcond_const:
-                tcg_opt_gen_movi(&ctx, op, op->args[0], i);
-                continue;
-            }
-            if ((op->args[5] == TCG_COND_LT || op->args[5] == TCG_COND_GE)
-                 && arg_is_const(op->args[3])
-                 && arg_info(op->args[3])->val == 0
-                 && arg_is_const(op->args[4])
-                 && arg_info(op->args[4])->val == 0) {
-                /* Simplify LT/GE comparisons vs zero to a single compare
-                   vs the high word of the input.  */
-            do_setcond_high:
-                reset_temp(op->args[0]);
-                arg_info(op->args[0])->z_mask = 1;
-                op->opc = INDEX_op_setcond_i32;
-                op->args[1] = op->args[2];
-                op->args[2] = op->args[4];
-                op->args[3] = op->args[5];
-                break;
-            }
-            if (op->args[5] == TCG_COND_EQ) {
-                /* Simplify EQ comparisons where one of the pairs
-                   can be simplified.  */
-                i = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                             op->args[1], op->args[3],
-                                             TCG_COND_EQ);
-                if (i == 0) {
-                    goto do_setcond_const;
-                } else if (i > 0) {
-                    goto do_setcond_high;
-                }
-                i = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                             op->args[2], op->args[4],
-                                             TCG_COND_EQ);
-                if (i == 0) {
-                    goto do_setcond_high;
-                } else if (i < 0) {
-                    break;
-                }
-            do_setcond_low:
-                reset_temp(op->args[0]);
-                arg_info(op->args[0])->z_mask = 1;
-                op->opc = INDEX_op_setcond_i32;
-                op->args[2] = op->args[3];
-                op->args[3] = op->args[5];
-                break;
-            }
-            if (op->args[5] == TCG_COND_NE) {
-                /* Simplify NE comparisons where one of the pairs
-                   can be simplified.  */
-                i = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                             op->args[1], op->args[3],
-                                             TCG_COND_NE);
-                if (i == 0) {
-                    goto do_setcond_high;
-                } else if (i > 0) {
-                    goto do_setcond_const;
-                }
-                i = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                             op->args[2], op->args[4],
-                                             TCG_COND_NE);
-                if (i == 0) {
-                    goto do_setcond_low;
-                } else if (i > 0) {
-                    goto do_setcond_const;
-                }
-            }
-            break;
-
         default:
             break;
 
@@ -1813,6 +1809,9 @@ void tcg_optimize(TCGContext *s)
         CASE_OP_32_64(shr):
             done = fold_shift(&ctx, op);
             break;
+        case INDEX_op_setcond2_i32:
+            done = fold_setcond2(&ctx, op);
+            break;
         CASE_OP_32_64_VEC(sub):
             done = fold_sub(&ctx, op);
             break;