This is an updated version of this patch as suggested by Richard but
it runs slower and only gets 5.9 seconds instead of 5.83-5.81 with v1
so this is not for merge, only for reference in case it can be useful
for further optimisation or can be fixed in some way.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
---
 target/ppc/helper.h     |  3 +--
 target/ppc/mem_helper.c | 16 +++-------------
 target/ppc/translate.c  | 18 ++++++++----------
 3 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 76b8f25c77..220653c834 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -46,8 +46,7 @@ DEF_HELPER_FLAGS_3(stmw, TCG_CALL_NO_WG, void, env, tl, i32)
 DEF_HELPER_4(lsw, void, env, tl, i32, i32)
 DEF_HELPER_5(lswx, void, env, tl, i32, i32, i32)
 DEF_HELPER_FLAGS_4(stsw, TCG_CALL_NO_WG, void, env, tl, i32, i32)
-DEF_HELPER_FLAGS_3(dcbz, TCG_CALL_NO_WG, void, env, tl, i32)
-DEF_HELPER_FLAGS_3(dcbzep, TCG_CALL_NO_WG, void, env, tl, i32)
+DEF_HELPER_FLAGS_4(dcbz, TCG_CALL_NO_WG, void, env, tl, i32, i32)
 DEF_HELPER_FLAGS_2(icbi, TCG_CALL_NO_WG, void, env, tl)
 DEF_HELPER_FLAGS_2(icbiep, TCG_CALL_NO_WG, void, env, tl)
 DEF_HELPER_5(lscbx, tl, env, tl, i32, i32, i32)
diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c
index f88155ad45..8f0c247df8 100644
--- a/target/ppc/mem_helper.c
+++ b/target/ppc/mem_helper.c
@@ -270,13 +270,13 @@ void helper_stsw(CPUPPCState *env, target_ulong addr, uint32_t nb,
     }
 }
 
-static void dcbz_common(CPUPPCState *env, target_ulong addr,
-                        uint32_t opcode, bool epid, uintptr_t retaddr)
+void helper_dcbz(CPUPPCState *env, target_ulong addr, uint32_t opcode,
+                 uint32_t mmu_idx)
 {
     target_ulong mask, dcbz_size = env->dcache_line_size;
     uint32_t i;
     void *haddr;
-    int mmu_idx = epid ? PPC_TLB_EPID_STORE : ppc_env_mmu_index(env, false);
+    uintptr_t retaddr = GETPC();
 
 #if defined(TARGET_PPC64)
     /* Check for dcbz vs dcbzl on 970 */
@@ -307,16 +307,6 @@ static void dcbz_common(CPUPPCState *env, target_ulong addr,
     }
 }
 
-void helper_dcbz(CPUPPCState *env, target_ulong addr, uint32_t opcode)
-{
-    dcbz_common(env, addr, opcode, false, GETPC());
-}
-
-void helper_dcbzep(CPUPPCState *env, target_ulong addr, uint32_t opcode)
-{
-    dcbz_common(env, addr, opcode, true, GETPC());
-}
-
 void helper_icbi(CPUPPCState *env, target_ulong addr)
 {
     addr &= ~(env->dcache_line_size - 1);
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 0bc16d7251..ca172dd664 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -4445,27 +4445,25 @@ static void gen_dcblc(DisasContext *ctx)
 /* dcbz */
 static void gen_dcbz(DisasContext *ctx)
 {
-    TCGv tcgv_addr;
-    TCGv_i32 tcgv_op;
+    TCGv tcgv_addr = tcg_temp_new();
 
     gen_set_access_type(ctx, ACCESS_CACHE);
-    tcgv_addr = tcg_temp_new();
-    tcgv_op = tcg_constant_i32(ctx->opcode & 0x03FF000);
     gen_addr_reg_index(ctx, tcgv_addr);
-    gen_helper_dcbz(tcg_env, tcgv_addr, tcgv_op);
+    gen_helper_dcbz(tcg_env, tcgv_addr,
+                    tcg_constant_i32(ctx->opcode & 0x03FF000),
+                    tcg_constant_i32(ctx->mem_idx));
 }
 
 /* dcbzep */
 static void gen_dcbzep(DisasContext *ctx)
 {
-    TCGv tcgv_addr;
-    TCGv_i32 tcgv_op;
+    TCGv tcgv_addr = tcg_temp_new();
 
     gen_set_access_type(ctx, ACCESS_CACHE);
-    tcgv_addr = tcg_temp_new();
-    tcgv_op = tcg_constant_i32(ctx->opcode & 0x03FF000);
     gen_addr_reg_index(ctx, tcgv_addr);
-    gen_helper_dcbzep(tcg_env, tcgv_addr, tcgv_op);
+    gen_helper_dcbz(tcg_env, tcgv_addr,
+                    tcg_constant_i32(ctx->opcode & 0x03FF000),
+                    tcg_constant_i32(PPC_TLB_EPID_STORE));
 }
 
 /* dst / dstt */
-- 
2.30.9