tcg: Use tcg_malloc to allocate TCGLabel

Pre-allocating 512 of them per TB is a waste.

Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 97aa512..f1558b7 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -246,15 +246,11 @@
 TCGLabel *gen_new_label(void)
 {
     TCGContext *s = &tcg_ctx;
-    int idx;
-    TCGLabel *l;
+    TCGLabel *l = tcg_malloc(sizeof(TCGLabel));
 
-    if (s->nb_labels >= TCG_MAX_LABELS)
-        tcg_abort();
-    idx = s->nb_labels++;
-    l = &s->labels[idx];
-    l->has_value = 0;
-    l->u.first_reloc = NULL;
+    *l = (TCGLabel){
+        .id = s->nb_labels++
+    };
 
     return l;
 }
@@ -1086,11 +1082,20 @@
                 i = 0;
                 break;
             }
-            for (; i < nb_cargs; i++) {
-                if (k != 0) {
-                    qemu_log(",");
-                }
-                qemu_log("$0x%" TCG_PRIlx, args[k++]);
+            switch (c) {
+            case INDEX_op_set_label:
+            case INDEX_op_br:
+            case INDEX_op_brcond_i32:
+            case INDEX_op_brcond_i64:
+            case INDEX_op_brcond2_i32:
+                qemu_log("%s$L%d", k ? "," : "", arg_label(args[k])->id);
+                i++, k++;
+                break;
+            default:
+                break;
+            }
+            for (; i < nb_cargs; i++, k++) {
+                qemu_log("%s$0x%" TCG_PRIlx, k ? "," : "", args[k]);
             }
         }
         qemu_log("\n");
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 1987d24..add7f75 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -167,7 +167,8 @@
 } TCGRelocation; 
 
 typedef struct TCGLabel {
-    int has_value;
+    unsigned has_value : 1;
+    unsigned id : 31;
     union {
         uintptr_t value;
         tcg_insn_unit *value_ptr;
@@ -183,8 +184,6 @@
 
 #define TCG_POOL_CHUNK_SIZE 32768
 
-#define TCG_MAX_LABELS 512
-
 #define TCG_MAX_TEMPS 512
 
 /* when the size of the arguments of a called function is smaller than
@@ -556,8 +555,6 @@
     target_ulong gen_opc_pc[OPC_BUF_SIZE];
     uint16_t gen_opc_icount[OPC_BUF_SIZE];
     uint8_t gen_opc_instr_start[OPC_BUF_SIZE];
-
-    TCGLabel labels[TCG_MAX_LABELS];
 };
 
 extern TCGContext tcg_ctx;
@@ -766,9 +763,7 @@
 
 static inline TCGArg label_arg(TCGLabel *l)
 {
-    ptrdiff_t idx = l - tcg_ctx.labels;
-    tcg_debug_assert(idx >= 0 && idx < tcg_ctx.nb_labels);
-    return idx;
+    return (uintptr_t)l;
 }
 
 /**
@@ -779,10 +774,9 @@
  * encoding of the TCG opcode stream.
  */
 
-static inline TCGLabel *arg_label(TCGArg idx)
+static inline TCGLabel *arg_label(TCGArg i)
 {
-    tcg_debug_assert(idx < tcg_ctx.nb_labels);
-    return &tcg_ctx.labels[idx];
+    return (TCGLabel *)(uintptr_t)i;
 }
 
 /**