Performance results for fp-bench run under aarch64-linux-user
on an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz host:
- before:
sqrt-single: 26.61 MFlops
sqrt-double: 17.14 MFlops
- after:
sqrt-single: 95.06 MFlops
sqrt-double: 89.05 MFlops
Note that here we have a single implementation for both f32/f64.
I tried the same trick we used before, but the results aren't
as good:
- w/ each using float32/64_is_normal or fpclassify etc.:
sqrt-single: 95.50 MFlops
sqrt-double: 84.55 MFlops
- w/ both using fpclassify etc.:
sqrt-single: 91.04 MFlops
sqrt-double: 85.55 MFlops
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
fpu/softfloat.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 2dedb13..ba7289b 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2436,20 +2436,42 @@ float16 __attribute__((flatten)) float16_sqrt(float16
a, float_status *status)
return float16_round_pack_canonical(pr, status);
}
-float32 __attribute__((flatten)) float32_sqrt(float32 a, float_status *status)
+static float32 __attribute__((flatten, noinline))
+soft_float32_sqrt(float32 a, float_status *status)
{
FloatParts pa = float32_unpack_canonical(a, status);
FloatParts pr = sqrt_float(pa, status, &float32_params);
return float32_round_pack_canonical(pr, status);
}
-float64 __attribute__((flatten)) float64_sqrt(float64 a, float_status *status)
+static float64 __attribute__((flatten, noinline))
+soft_float64_sqrt(float64 a, float_status *status)
{
FloatParts pa = float64_unpack_canonical(a, status);
FloatParts pr = sqrt_float(pa, status, &float64_params);
return float64_round_pack_canonical(pr, status);
}
+#define GEN_FPU_SQRT(name, soft_t, host_t, host_sqrt_func) \
+ soft_t name(soft_t a, float_status *s) \
+ { \
+ soft_t ## _input_flush1(&a, s); \
+ if (likely((soft_t ## _is_normal(a) || soft_t ## _is_zero(a)) && \
+ !soft_t ## _is_neg(a) && \
+ s->float_exception_flags & float_flag_inexact && \
+ s->float_rounding_mode == float_round_nearest_even)) { \
+ host_t ha = soft_t ## _to_ ## host_t(a); \
+ host_t hr = host_sqrt_func(ha); \
+ \
+ return host_t ## _to_ ## soft_t(hr); \
+ } \
+ return soft_ ## soft_t ## _sqrt(a, s); \
+ }
+
+GEN_FPU_SQRT(float32_sqrt, float32, float, sqrtf)
+GEN_FPU_SQRT(float64_sqrt, float64, double, sqrt)
+#undef GEN_FPU_SQRT
+
/*----------------------------------------------------------------------------
| Takes a 64-bit fixed-point value `absZ' with binary point between bits 6
--
2.7.4
