target-ppc: convert mfrom instruction to TCG

Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5823 c046a42c-6fe2-441c-8c8c-71466251a162

target-ppc/helper.h

@@ -144,6 +144,8 @@ DEF_HELPER_1(load_6xx_tlbd, void, tl)
 DEF_HELPER_1(load_6xx_tlbi, void, tl)
 DEF_HELPER_1(load_74xx_tlbd, void, tl)
 DEF_HELPER_1(load_74xx_tlbi, void, tl)
+
+DEF_HELPER_1(602_mfrom, tl, tl)
 #endif
 
 #include "def-helper.h"

target-ppc/op.c

@@ -684,15 +684,6 @@ void OPPROTO op_POWER_rfsvc (void)
 }
 #endif
 
-/* PowerPC 602 specific instruction */
-#if !defined(CONFIG_USER_ONLY)
-void OPPROTO op_602_mfrom (void)
-{
-    do_op_602_mfrom();
-    RETURN();
-}
-#endif
-
 /* PowerPC 4xx specific micro-ops */
 void OPPROTO op_load_dcr (void)
 {

target-ppc/op_helper.c

@@ -1645,19 +1645,19 @@ void do_store_hid0_601 (void)
 /* mfrom is the most crazy instruction ever seen, imho ! */
 /* Real implementation uses a ROM table. Do the same */
 #define USE_MFROM_ROM_TABLE
-void do_op_602_mfrom (void)
+target_ulong helper_602_mfrom (target_ulong arg)
 {
-    if (likely(T0 < 602)) {
+    if (likely(arg < 602)) {
 #if defined(USE_MFROM_ROM_TABLE)
 #include "mfrom_table.c"
-        T0 = mfrom_ROM_table[T0];
+        return mfrom_ROM_table[T0];
 #else
         double d;
         /* Extremly decomposed:
-         *                    -T0 / 256
-         * T0 = 256 * log10(10          + 1.0) + 0.5
+         *                      -arg / 256
+         * return 256 * log10(10           + 1.0) + 0.5
          */
-        d = T0;
+        d = arg;
         d = float64_div(d, 256, &env->fp_status);
         d = float64_chs(d);
         d = exp10(d); // XXX: use float emulation function
@@ -1665,10 +1665,10 @@ void do_op_602_mfrom (void)
         d = log10(d); // XXX: use float emulation function
         d = float64_mul(d, 256, &env->fp_status);
         d = float64_add(d, 0.5, &env->fp_status);
-        T0 = float64_round_to_int(d, &env->fp_status);
+        return float64_round_to_int(d, &env->fp_status);
 #endif
     } else {
-        T0 = 0;
+        return 0;
     }
 }
 

target-ppc/translate.c

@@ -4948,9 +4948,7 @@ GEN_HANDLER(mfrom, 0x1F, 0x09, 0x08, 0x03E0F801, PPC_602_SPEC)
         GEN_EXCP_PRIVOPC(ctx);
         return;
     }
-    tcg_gen_mov_tl(cpu_T[0], cpu_gpr[rA(ctx->opcode)]);
-    gen_op_602_mfrom();
-    tcg_gen_mov_tl(cpu_gpr[rD(ctx->opcode)], cpu_T[0]);
+    gen_helper_602_mfrom(cpu_gpr[rD(ctx->opcode)], cpu_gpr[rA(ctx->opcode)]);
 #endif
 }