[Qemu-devel] [6083] target-ppc: fix fres, fsqrte and remove useless code

[Qemu-devel] [6083] target-ppc: fix fres, fsqrte and remove useless code

[Aurelien Jarno]

Revision: 6083
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6083
Author:   aurel32
Date:     2008-12-18 22:42:23 +0000 (Thu, 18 Dec 2008)

Log Message:
-----------
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: Aurelien Jarno <aurelien@aurel32.net>

Modified Paths:
--------------
    trunk/target-ppc/op_helper.c

Modified: trunk/target-ppc/op_helper.c
===================================================================
--- trunk/target-ppc/op_helper.c	2008-12-18 01:56:22 UTC (rev 6082)
+++ trunk/target-ppc/op_helper.c	2008-12-18 22:42:23 UTC (rev 6083)
@@ -563,18 +563,6 @@
     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 @@
     } 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_fres (uint64_t arg)
 {
     CPU_DoubleU fone, farg;
+    float32 f32;
     fone.ll = 0x3FF0000000000000ULL; /* 1.0 */
     farg.ll = arg;
 
@@ -1559,25 +1536,10 @@
     } 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_frsqrte (uint64_t arg)
 {
     CPU_DoubleU fone, farg;
+    float32 f32;
     fone.ll = 0x3FF0000000000000ULL; /* 1.0 */
     farg.ll = arg;
 
@@ -1595,21 +1558,11 @@
     } 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;
 }