tcg: Add TCG_CALL_RET_BY_VEC

This will be used by _WIN64 to return i128.  Not yet used,
because allocation is not yet enabled.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/tcg-internal.h

@@ -37,6 +37,7 @@
 typedef enum {
     TCG_CALL_RET_NORMAL,         /* by registers */
     TCG_CALL_RET_BY_REF,         /* for i128, by reference */
+    TCG_CALL_RET_BY_VEC,         /* for i128, by vector register */
 } TCGCallReturnKind;
 
 typedef enum {

tcg/tcg.c

@@ -752,6 +752,10 @@ static void init_call_layout(TCGHelperInfo *info)
             /* Query the last register now to trigger any assert early. */
             tcg_target_call_oarg_reg(info->out_kind, info->nr_out - 1);
             break;
+        case TCG_CALL_RET_BY_VEC:
+            /* Query the single register now to trigger any assert early. */
+            tcg_target_call_oarg_reg(TCG_CALL_RET_BY_VEC, 0);
+            break;
         case TCG_CALL_RET_BY_REF:
             /*
              * Allocate the first argument to the output.
@@ -4605,6 +4609,21 @@ static void tcg_reg_alloc_call(TCGContext *s, TCGOp *op)
         }
         break;
 
+    case TCG_CALL_RET_BY_VEC:
+        {
+            TCGTemp *ts = arg_temp(op->args[0]);
+
+            tcg_debug_assert(ts->base_type == TCG_TYPE_I128);
+            tcg_debug_assert(ts->temp_subindex == 0);
+            if (!ts->mem_allocated) {
+                temp_allocate_frame(s, ts);
+            }
+            tcg_out_st(s, TCG_TYPE_V128,
+                       tcg_target_call_oarg_reg(TCG_CALL_RET_BY_VEC, 0),
+                       ts->mem_base->reg, ts->mem_offset);
+        }
+        /* fall through to mark all parts in memory */
+
     case TCG_CALL_RET_BY_REF:
         /* The callee has performed a write through the reference. */
         for (i = 0; i < nb_oargs; i++) {