Performance results for fp-bench:
1. Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
- before:
div-single: 34.84 MFlops
div-double: 34.04 MFlops
- after:
div-single: 275.23 MFlops
div-double: 216.38 MFlops
2. ARM Aarch64 A57 @ 2.4GHz
- before:
div-single: 9.33 MFlops
div-double: 9.30 MFlops
- after:
div-single: 51.55 MFlops
div-double: 15.09 MFlops
3. IBM POWER8E @ 2.1 GHz
- before:
div-single: 25.65 MFlops
div-double: 24.91 MFlops
- after:
div-single: 96.83 MFlops
div-double: 31.01 MFlops
Here setting 2FP64_USE_FP to 1 pays off for x86_64:
[1] 215.97 vs [0] 62.15 MFlops
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
fpu/softfloat.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 86 insertions(+), 2 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 4fcabf6..fa6c3b6 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1659,7 +1659,8 @@ float16 float16_div(float16 a, float16 b, float_status
*status)
return float16_round_pack_canonical(pr, status);
}
-float32 float32_div(float32 a, float32 b, float_status *status)
+static float32 QEMU_SOFTFLOAT_ATTR
+soft_float32_div(float32 a, float32 b, float_status *status)
{
FloatParts pa = float32_unpack_canonical(a, status);
FloatParts pb = float32_unpack_canonical(b, status);
@@ -1668,7 +1669,8 @@ float32 float32_div(float32 a, float32 b, float_status
*status)
return float32_round_pack_canonical(pr, status);
}
-float64 float64_div(float64 a, float64 b, float_status *status)
+static float64 QEMU_SOFTFLOAT_ATTR
+soft_float64_div(float64 a, float64 b, float_status *status)
{
FloatParts pa = float64_unpack_canonical(a, status);
FloatParts pb = float64_unpack_canonical(b, status);
@@ -1677,6 +1679,88 @@ float64 float64_div(float64 a, float64 b, float_status
*status)
return float64_round_pack_canonical(pr, status);
}
+static float float_div(float a, float b)
+{
+ return a / b;
+}
+
+static double double_div(double a, double b)
+{
+ return a / b;
+}
+
+static bool f32_div_pre(float32 a, float32 b, const struct float_status *s)
+{
+ return likely(float32_is_zero_or_normal(a) &&
+ float32_is_normal(b) &&
+ can_use_fpu(s));
+}
+
+static bool f64_div_pre(float64 a, float64 b, const struct float_status *s)
+{
+ return likely(float64_is_zero_or_normal(a) &&
+ float64_is_normal(b) &&
+ can_use_fpu(s));
+}
+
+static bool float_div_pre(float a, float b, const struct float_status *s)
+{
+ return likely((fpclassify(a) == FP_NORMAL || fpclassify(a) == FP_ZERO) &&
+ fpclassify(b) == FP_NORMAL &&
+ can_use_fpu(s));
+}
+
+static bool double_div_pre(double a, double b, const struct float_status *s)
+{
+ return likely((fpclassify(a) == FP_NORMAL || fpclassify(a) == FP_ZERO) &&
+ fpclassify(b) == FP_NORMAL &&
+ can_use_fpu(s));
+}
+
+static bool f32_div_post(float32 a, float32 b, const struct float_status *s)
+{
+ return !float32_is_zero(a);
+}
+
+static bool f64_div_post(float64 a, float64 b, const struct float_status *s)
+{
+ return !float64_is_zero(a);
+}
+
+static bool float_div_post(float a, float b, const struct float_status *s)
+{
+ return fpclassify(a) != FP_ZERO;
+}
+
+static bool double_div_post(double a, double b, const struct float_status *s)
+{
+ return fpclassify(a) != FP_ZERO;
+}
+
+float32 __attribute__((flatten))
+float32_div(float32 a, float32 b, float_status *s)
+{
+ if (QEMU_HARDFLOAT_2F32_USE_FP) {
+ return float_gen2(a, b, s, float_div, soft_float32_div, float_div_pre,
+ float_div_post, NULL, NULL);
+ } else {
+ return f32_gen2(a, b, s, float_div, soft_float32_div, f32_div_pre,
+ f32_div_post, NULL, NULL);
+ }
+}
+
+float64 __attribute__((flatten))
+float64_div(float64 a, float64 b, float_status *s)
+{
+ if (QEMU_HARDFLOAT_2F64_USE_FP) {
+ return double_gen2(a, b, s, double_div, soft_float64_div,
+ double_div_pre, double_div_post, NULL, NULL);
+ } else {
+ return f64_gen2(a, b, s, double_div, soft_float64_div, f64_div_pre,
+ f64_div_post, NULL, NULL);
+ }
+}
+
/*
* Float to Float conversions
*
--
2.7.4
