target/ppc: Merge COMPUTE_CLASS and COMPUTE_FPRF

Instead of computing an artificial "class" bitmask then converting that to the fprf value, compute the final value from the start. Reorder the tests to check the most likely cases first. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230523202507.688859-1-richard.henderson@linaro.org> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
qemu · May 28, 2023 · 03ec9d9 · 03ec9d9
1 parent 76f9ebf
commit 03ec9d9
Showing 1 changed file with 22 additions and 56 deletions.
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
@@ -141,62 +141,28 @@ static inline int ppc_float64_get_unbiased_exp(float64 f)
     return ((f >> 52) & 0x7FF) - 1023;
 }
 
-/* Classify a floating-point number.  */
-enum {
-    is_normal   = 1,
-    is_zero     = 2,
-    is_denormal = 4,
-    is_inf      = 8,
-    is_qnan     = 16,
-    is_snan     = 32,
-    is_neg      = 64,
-};
-
-#define COMPUTE_CLASS(tp)                                      \
-static int tp##_classify(tp arg)                               \
-{                                                              \
-    int ret = tp##_is_neg(arg) * is_neg;                       \
-    if (unlikely(tp##_is_any_nan(arg))) {                      \
-        float_status dummy = { };  /* snan_bit_is_one = 0 */   \
-        ret |= (tp##_is_signaling_nan(arg, &dummy)             \
-                ? is_snan : is_qnan);                          \
-    } else if (unlikely(tp##_is_infinity(arg))) {              \
-        ret |= is_inf;                                         \
-    } else if (tp##_is_zero(arg)) {                            \
-        ret |= is_zero;                                        \
-    } else if (tp##_is_zero_or_denormal(arg)) {                \
-        ret |= is_denormal;                                    \
-    } else {                                                   \
-        ret |= is_normal;                                      \
-    }                                                          \
-    return ret;                                                \
-}
-
-COMPUTE_CLASS(float16)
-COMPUTE_CLASS(float32)
-COMPUTE_CLASS(float64)
-COMPUTE_CLASS(float128)
-
-static void set_fprf_from_class(CPUPPCState *env, int class)
-{
-    static const uint8_t fprf[6][2] = {
-        { 0x04, 0x08 },  /* normalized */
-        { 0x02, 0x12 },  /* zero */
-        { 0x14, 0x18 },  /* denormalized */
-        { 0x05, 0x09 },  /* infinity */
-        { 0x11, 0x11 },  /* qnan */
-        { 0x00, 0x00 },  /* snan -- flags are undefined */
-    };
-    bool isneg = class & is_neg;
-
-    env->fpscr &= ~FP_FPRF;
-    env->fpscr |= fprf[ctz32(class)][isneg] << FPSCR_FPRF;
-}
-
-#define COMPUTE_FPRF(tp)                                \
-void helper_compute_fprf_##tp(CPUPPCState *env, tp arg) \
-{                                                       \
-    set_fprf_from_class(env, tp##_classify(arg));       \
+#define COMPUTE_FPRF(tp)                                          \
+void helper_compute_fprf_##tp(CPUPPCState *env, tp arg)           \
+{                                                                 \
+    bool neg = tp##_is_neg(arg);                                  \
+    target_ulong fprf;                                            \
+    if (likely(tp##_is_normal(arg))) {                            \
+        fprf = neg ? 0x08 << FPSCR_FPRF : 0x04 << FPSCR_FPRF;     \
+    } else if (tp##_is_zero(arg)) {                               \
+        fprf = neg ? 0x12 << FPSCR_FPRF : 0x02 << FPSCR_FPRF;     \
+    } else if (tp##_is_zero_or_denormal(arg)) {                   \
+        fprf = neg ? 0x18 << FPSCR_FPRF : 0x14 << FPSCR_FPRF;     \
+    } else if (tp##_is_infinity(arg)) {                           \
+        fprf = neg ? 0x09 << FPSCR_FPRF : 0x05 << FPSCR_FPRF;     \
+    } else {                                                      \
+        float_status dummy = { };  /* snan_bit_is_one = 0 */      \
+        if (tp##_is_signaling_nan(arg, &dummy)) {                 \
+            fprf = 0x00 << FPSCR_FPRF;                            \
+        } else {                                                  \
+            fprf = 0x11 << FPSCR_FPRF;                            \
+        }                                                         \
+    }                                                             \
+    env->fpscr = (env->fpscr & ~FP_FPRF) | fprf;                  \
 }
 
 COMPUTE_FPRF(float16)