target-ppc: fix fres, fsqrte and remove useless code

- fres and fsqrte should not assign a float32 number to a float64 value.
- fre, fres and fsqrte are checking for cases already taken into account
  by softfloat and softfloat native. Remove those useless tests.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6083 c046a42c-6fe2-441c-8c8c-71466251a162

target-ppc/op_helper.c

@@ -563,18 +563,6 @@ static always_inline int isden (float64 d)
     return ((u.ll >> 52) & 0x7FF) == 0;
 }
 
-#ifdef CONFIG_SOFTFLOAT
-static always_inline int isnormal (float64 d)
-{
-    CPU_DoubleU u;
-
-    u.d = d;
-
-    uint32_t exp = (u.ll >> 52) & 0x7FF;
-    return ((0 < exp) && (exp < 0x7FF));
-}
-#endif
-
 uint32_t helper_compute_fprf (uint64_t arg, uint32_t set_fprf)
 {
     CPU_DoubleU farg;
@@ -1528,20 +1516,8 @@ uint64_t helper_fre (uint64_t arg)
     } else if (unlikely(float64_is_zero(farg.d))) {
         /* Zero reciprocal */
         farg.ll = float_zero_divide_excp(fone.d, farg.d);
-    } else if (likely(isnormal(farg.d))) {
-        farg.d = float64_div(fone.d, farg.d, &env->fp_status);
     } else {
-        if (farg.ll == 0x8000000000000000ULL) {
-            farg.ll = 0xFFF0000000000000ULL;
-        } else if (farg.ll == 0x0000000000000000ULL) {
-            farg.ll = 0x7FF0000000000000ULL;
-        } else if (float64_is_nan(farg.d)) {
-            farg.ll = 0x7FF8000000000000ULL;
-        } else if (float64_is_neg(farg.d)) {
-            farg.ll = 0x8000000000000000ULL;
-        } else {
-            farg.ll = 0x0000000000000000ULL;
-        }
+        farg.d = float64_div(fone.d, farg.d, &env->fp_status);
     }
     return farg.d;
 }
@@ -1550,6 +1526,7 @@ uint64_t helper_fre (uint64_t arg)
 uint64_t helper_fres (uint64_t arg)
 {
     CPU_DoubleU fone, farg;
+    float32 f32;
     fone.ll = 0x3FF0000000000000ULL; /* 1.0 */
     farg.ll = arg;
 
@@ -1559,25 +1536,10 @@ uint64_t helper_fres (uint64_t arg)
     } else if (unlikely(float64_is_zero(farg.d))) {
         /* Zero reciprocal */
         farg.ll = float_zero_divide_excp(fone.d, farg.d);
-    } else if (likely(isnormal(farg.d))) {
-#if USE_PRECISE_EMULATION
-        farg.d = float64_div(fone.d, farg.d, &env->fp_status);
-        farg.d = float64_to_float32(farg.d, &env->fp_status);
-#else
-        farg.d = float32_div(fone.d, farg.d, &env->fp_status);
-#endif
     } else {
-        if (farg.ll == 0x8000000000000000ULL) {
-            farg.ll = 0xFFF0000000000000ULL;
-        } else if (farg.ll == 0x0000000000000000ULL) {
-            farg.ll = 0x7FF0000000000000ULL;
-        } else if (float64_is_nan(farg.d)) {
-            farg.ll = 0x7FF8000000000000ULL;
-        } else if (float64_is_neg(farg.d)) {
-            farg.ll = 0x8000000000000000ULL;
-        } else {
-            farg.ll = 0x0000000000000000ULL;
-        }
+        farg.d = float64_div(fone.d, farg.d, &env->fp_status);
+        f32 = float64_to_float32(farg.d, &env->fp_status);
+        farg.d = float32_to_float64(f32, &env->fp_status);
     }
     return farg.ll;
 }
@@ -1586,6 +1548,7 @@ uint64_t helper_fres (uint64_t arg)
 uint64_t helper_frsqrte (uint64_t arg)
 {
     CPU_DoubleU fone, farg;
+    float32 f32;
     fone.ll = 0x3FF0000000000000ULL; /* 1.0 */
     farg.ll = arg;
 
@@ -1595,21 +1558,11 @@ uint64_t helper_frsqrte (uint64_t arg)
     } else if (unlikely(float64_is_neg(farg.d) && !float64_is_zero(farg.d))) {
         /* Reciprocal square root of a negative nonzero number */
         farg.ll = fload_invalid_op_excp(POWERPC_EXCP_FP_VXSQRT);
-    } else if (likely(isnormal(farg.d))) {
-        farg.d = float64_sqrt(farg.d, &env->fp_status);
-        farg.d = float32_div(fone.d, farg.d, &env->fp_status);
     } else {
-        if (farg.ll == 0x8000000000000000ULL) {
-            farg.ll = 0xFFF0000000000000ULL;
-        } else if (farg.ll == 0x0000000000000000ULL) {
-            farg.ll = 0x7FF0000000000000ULL;
-        } else if (float64_is_nan(farg.d)) {
-            farg.ll |= 0x000FFFFFFFFFFFFFULL;
-        } else if (float64_is_neg(farg.d)) {
-            farg.ll = 0x7FF8000000000000ULL;
-        } else {
-            farg.ll = 0x0000000000000000ULL;
-        }
+        farg.d = float64_sqrt(farg.d, &env->fp_status);
+        farg.d = float64_div(fone.d, farg.d, &env->fp_status);
+        f32 = float64_to_float32(farg.d, &env->fp_status);
+        farg.d = float32_to_float64(f32, &env->fp_status);
     }
     return farg.ll;
 }