tcg: Change translator-side labels to a pointer

This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.

Note that the code generating backends still manipulate labels as int.

With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Anthony Green <green@moxielogic.com>
Cc: Jia Liu <proljc@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/tcg/tcg.h b/tcg/tcg.h
index f941965d53..1987d24dc8 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -755,6 +755,36 @@ TCGv_i64 tcg_const_i64(int64_t val);
 TCGv_i32 tcg_const_local_i32(int32_t val);
 TCGv_i64 tcg_const_local_i64(int64_t val);
 
+TCGLabel *gen_new_label(void);
+
+/**
+ * label_arg
+ * @l: label
+ *
+ * Encode a label for storage in the TCG opcode stream.
+ */
+
+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;
+}
+
+/**
+ * arg_label
+ * @i: value
+ *
+ * The opposite of label_arg.  Retrieve a label from the
+ * encoding of the TCG opcode stream.
+ */
+
+static inline TCGLabel *arg_label(TCGArg idx)
+{
+    tcg_debug_assert(idx < tcg_ctx.nb_labels);
+    return &tcg_ctx.labels[idx];
+}
+
 /**
  * tcg_ptr_byte_diff
  * @a, @b: addresses to be differenced