[Qemu-devel] [RFC][PATCH v0 6/8] Spill globals early if their next use is in call.

[Kirill Batuzov]

Spill globals early if their next use is in call. They'll be spilled
anyway in this case.

Signed-off-by: Kirill Batuzov <address@hidden>
---
 tcg/tcg.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 8ab556d..ad5bd71 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1297,6 +1297,11 @@ static void tcg_liveness_analysis(TCGContext *s)
                     if (!(call_flags & TCG_CALL_CONST)) {
                         /* globals are live (they may be used by the call) */
                         memset(dead_temps, 0, s->nb_globals);
+#ifdef USE_ADVANCED_REGALLOC
+                        for (i = 0; i < s->nb_globals; i++) {
+                            temp_next_use[i] = op_index;
+                        }
+#endif
                     }
 
                     /* input args are live */
@@ -1393,6 +1398,11 @@ static void tcg_liveness_analysis(TCGContext *s)
                 } else if (def->flags & TCG_OPF_CALL_CLOBBER) {
                     /* globals are live */
                     memset(dead_temps, 0, s->nb_globals);
+#ifdef USE_ADVANCED_REGALLOC
+                    for (i = 0; i < s->nb_globals; i++) {
+                        temp_next_use[i] = op_index;
+                    }
+#endif
                 }
 
                 /* input args are live */
@@ -2190,6 +2200,14 @@ static inline int tcg_gen_code_common(TCGContext *s, 
uint8_t *gen_code_buf,
 #endif
             dead_iargs = s->op_dead_iargs[op_index];
             tcg_reg_alloc_mov(s, def, args, param_next_use_ptr, dead_iargs);
+#ifdef USE_ADVANCED_REGALLOC
+            if (args[0] < s->nb_globals) {
+                if (tcg_op_defs[gen_opc_buf[param_next_use_ptr[0]]].flags
+                        & TCG_OPF_CALL_CLOBBER) {
+                    tcg_reg_free(s, s->temps[args[0]].reg);
+                }
+            }
+#endif
             break;
         case INDEX_op_movi_i32:
 #if TCG_TARGET_REG_BITS == 64
-- 
1.7.4.1