diff mbox series

[PULL,08/10] target/ppc: Merge COMPUTE_CLASS and COMPUTE_FPRF

Message ID 20230528164922.20364-9-danielhb413@gmail.com (mailing list archive)
State New, archived
Headers show
Series [PULL,01/10] target/ppc: Fix fallback to MFSS for MFFS* instructions on pre 3.0 ISAs | expand

Commit Message

Daniel Henrique Barboza May 28, 2023, 4:49 p.m. UTC 
From: Richard Henderson <richard.henderson@linaro.org>

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>
---
 target/ppc/fpu_helper.c | 78 ++++++++++++-----------------------------
 1 file changed, 22 insertions(+), 56 deletions(-)
diff mbox series

Patch

diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index a66e16c212..03150a0f10 100644
--- 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)