[Qemu-devel] [PATCH for-next 10/15] tcg-ppc64: Use indirect jump threading

[Richard Henderson <rth@twiddle.net>]

We were always doing an indirect jump anyway, and the sequence is
never longer than the 6 insns we were reserving for the direct jump.
Futher cleanups will reduce the length of the constant address load.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 include/exec/exec-all.h |  3 ++-
 tcg/ppc64/tcg-target.c  | 26 ++++++++------------------
 2 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index b3402a1..26c3553 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -126,7 +126,8 @@ static inline void tlb_flush(CPUArchState *env, int flush_global)
 #define CODE_GEN_AVG_BLOCK_SIZE 64
 #endif
 
-#if defined(__arm__) || defined(_ARCH_PPC) \
+#if defined(__arm__) \
+    || (defined(__powerpc__) && !defined(__powerpc64__)) \
     || defined(__x86_64__) || defined(__i386__) \
     || defined(__sparc__) || defined(__aarch64__) \
     || defined(CONFIG_TCG_INTERPRETER)
diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
index e9c41fb..f69bc8f 100644
--- a/tcg/ppc64/tcg-target.c
+++ b/tcg/ppc64/tcg-target.c
@@ -1440,17 +1440,6 @@ static void tcg_out_movcond(TCGContext *s, TCGType type, TCGCond cond,
     }
 }
 
-void ppc_tb_set_jmp_target (unsigned long jmp_addr, unsigned long addr)
-{
-    TCGContext s;
-    unsigned long patch_size;
-
-    s.code_ptr = (uint8_t *) jmp_addr;
-    tcg_out_b (&s, 0, addr);
-    patch_size = s.code_ptr - (uint8_t *) jmp_addr;
-    flush_icache_range (jmp_addr, jmp_addr + patch_size);
-}
-
 static void tcg_out_op (TCGContext *s, TCGOpcode opc, const TCGArg *args,
                         const int *const_args)
 {
@@ -1464,13 +1453,14 @@ static void tcg_out_op (TCGContext *s, TCGOpcode opc, const TCGArg *args,
         break;
     case INDEX_op_goto_tb:
         if (s->tb_jmp_offset) {
-            /* direct jump method */
-
-            s->tb_jmp_offset[args[0]] = s->code_ptr - s->code_buf;
-            s->code_ptr += 28;
-        }
-        else {
-            tcg_abort ();
+            /* Direct jump method. */
+            tcg_abort();
+        } else {
+            /* Indirect jump method. */
+            tcg_out_mem_long(s, LD, LDX, TCG_REG_R0, TCG_REG_R0,
+                             (tcg_target_long)(s->tb_next + args[0]));
+            tcg_out32(s, MTSPR | RS(TCG_REG_R0) | CTR);
+            tcg_out32(s, BCCTR | BO_ALWAYS);
         }
         s->tb_next_offset[args[0]] = s->code_ptr - s->code_buf;
         break;
-- 
1.8.3.1