[Qemu-devel] [PATCH v2] ppc: Convert op_405_check_{sat,satu} to TCG

[Andreas Färber]

Replace op_405_check_satu with a conditional movi_tl.

Replace {op,do}_405_check_sat with inline TCG instructions.

Signed-off-by: Andreas Faerber <address@hidden>
---
 Updated with simplifications suggested by Paul Brook.
 Still only compile-tested - please verify whether I got the logic  
right.

 target-ppc/op.c        |   15 ---------------
 target-ppc/op_helper.c |   12 ------------
 target-ppc/translate.c |   22 ++++++++++++++++++----
 3 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/target-ppc/op.c b/target-ppc/op.c
index bcdb11d..f9b1910 100644
--- a/target-ppc/op.c
+++ b/target-ppc/op.c
@@ -1502,12 +1502,6 @@ void OPPROTO op_405_mullhwu (void)
     RETURN();
 }

-void OPPROTO op_405_check_sat (void)
-{
-    do_405_check_sat();
-    RETURN();
-}
-
 void OPPROTO op_405_check_ovu (void)
 {
     if (likely(T0 >= T2)) {
@@ -1518,15 +1512,6 @@ void OPPROTO op_405_check_ovu (void)
     RETURN();
 }

-void OPPROTO op_405_check_satu (void)
-{
-    if (unlikely(T0 < T2)) {
-        /* Saturate result */
-        T0 = UINT32_MAX;
-    }
-    RETURN();
-}
-
 void OPPROTO op_load_dcr (void)
 {
     do_load_dcr();
diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
index 32b3471..e78ba82 100644
--- a/target-ppc/op_helper.c
+++ b/target-ppc/op_helper.c
@@ -1729,18 +1729,6 @@ void do_op_602_mfrom (void)

 / 
*****************************************************************************/
 /* Embedded PowerPC specific helpers */
-void do_405_check_sat (void)
-{
-    if (!likely((((uint32_t)T1 ^ (uint32_t)T2) >> 31) ||
-                !(((uint32_t)T0 ^ (uint32_t)T2) >> 31))) {
-        /* Saturate result */
-        if (T2 >> 31) {
-            T0 = INT32_MIN;
-        } else {
-            T0 = INT32_MAX;
-        }
-    }
-}

 /* XXX: to be improved to check access rights when in user-mode */
 void do_load_dcr (void)
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index a977ea4..2a4a70d 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -5106,10 +5106,24 @@ static always_inline void gen_405_mulladd_insn  
(DisasContext *ctx,
     }
     if (opc3 & 0x02) {
         /* Saturate */
-        if (opc3 & 0x01)
-            gen_op_405_check_sat();
-        else
-            gen_op_405_check_satu();
+        int endLabel = gen_new_label();
+        if (opc3 & 0x01) {
+            TCGv tmp = tcg_temp_new(TCG_TYPE_TL);
+            tcg_gen_xor_tl(tmp, cpu_T[1], cpu_T[2]);
+            tcg_gen_brcondi_tl(TCG_COND_GE, tmp, 0, endLabel);
+
+            tcg_gen_xor_tl(tmp, cpu_T[0], cpu_T[2]);
+            tcg_gen_brcondi_tl(TCG_COND_LT, tmp, 0, endLabel);
+
+            tcg_gen_shri_tl(tmp, cpu_T[2], 31);
+            tcg_gen_xori_tl(cpu_T[0], tmp, 0x7fffffff);
+
+            tcg_temp_free(tmp);
+        } else {
+            tcg_gen_brcond_tl(TCG_COND_GEU, cpu_T[0], cpu_T[2],  
endLabel);
+            tcg_gen_movi_tl(cpu_T[0], UINT32_MAX);
+        }
+        gen_set_label(endLabel);
     }
     tcg_gen_mov_tl(cpu_gpr[rt], cpu_T[0]);
     if (unlikely(Rc) != 0) {
--
1.5.6.5

op_405_check_sat.patch
Description: Binary data