[Qemu-devel] [PATCH 1/9] TCG "sync" op

[Ulrich Hecht <uli@suse.de>]

sync allows concurrent accesses to locations in memory through different TCG
variables. This comes in handy when you are emulating CPU registers that can
be used as either 32 or 64 bit, as TCG doesn't know anything about aliases.
See the s390x target for an example.

Fixed sync_i64 build failure on 32-bit targets.

Signed-off-by: Ulrich Hecht <uli@suse.de>
---
 tcg/tcg-op.h  |   12 ++++++++++++
 tcg/tcg-opc.h |    2 ++
 tcg/tcg.c     |    6 ++++++
 3 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index faf2e8b..c1b4710 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -316,6 +316,18 @@ static inline void tcg_gen_br(int label)
     tcg_gen_op1i(INDEX_op_br, label);
 }
 
+static inline void tcg_gen_sync_i32(TCGv_i32 arg)
+{
+    tcg_gen_op1_i32(INDEX_op_sync_i32, arg);
+}
+
+#if TCG_TARGET_REG_BITS == 64
+static inline void tcg_gen_sync_i64(TCGv_i64 arg)
+{
+    tcg_gen_op1_i64(INDEX_op_sync_i64, arg);
+}
+#endif
+
 static inline void tcg_gen_mov_i32(TCGv_i32 ret, TCGv_i32 arg)
 {
     if (!TCGV_EQUAL_I32(ret, arg))
diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h
index b7f3fd7..5dcdeba 100644
--- a/tcg/tcg-opc.h
+++ b/tcg/tcg-opc.h
@@ -40,6 +40,7 @@ DEF2(call, 0, 1, 2, TCG_OPF_SIDE_EFFECTS) /* variable number of parameters */
 DEF2(jmp, 0, 1, 0, TCG_OPF_BB_END | TCG_OPF_SIDE_EFFECTS)
 DEF2(br, 0, 0, 1, TCG_OPF_BB_END | TCG_OPF_SIDE_EFFECTS)
 
+DEF2(sync_i32, 0, 1, 0, 0)
 DEF2(mov_i32, 1, 1, 0, 0)
 DEF2(movi_i32, 1, 0, 1, 0)
 /* load/store */
@@ -109,6 +110,7 @@ DEF2(neg_i32, 1, 1, 0, 0)
 #endif
 
 #if TCG_TARGET_REG_BITS == 64
+DEF2(sync_i64, 0, 1, 0, 0)
 DEF2(mov_i64, 1, 1, 0, 0)
 DEF2(movi_i64, 1, 0, 1, 0)
 /* load/store */
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3c0e296..8eb60f8 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1930,6 +1930,12 @@ static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
         //        dump_regs(s);
 #endif
         switch(opc) {
+        case INDEX_op_sync_i32:
+#if TCG_TARGET_REG_BITS == 64
+        case INDEX_op_sync_i64:
+#endif
+            temp_save(s, args[0], s->reserved_regs);
+            break;
         case INDEX_op_mov_i32:
 #if TCG_TARGET_REG_BITS == 64
         case INDEX_op_mov_i64:
-- 
1.6.2.1