Add LUT for quantized sigmoid function

* Move LUT implementation to a seperate file. It will be used
  for both QASYMM8 and QASYMM8_SIGNED.
* Fix wrong constant value related to QASYMM8_SIGNED leaky ReLU
  in 32-bit build.

Resolves: COMPMID-5464
Signed-off-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Change-Id: I2b24d52409a38f1b66fd532f431eff8a9e4547b6
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/8066
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/arm_compute/core/QuantizationInfo.h b/arm_compute/core/QuantizationInfo.h
index 21d962d08b..ed1025edc0 100644
--- a/arm_compute/core/QuantizationInfo.h
+++ b/arm_compute/core/QuantizationInfo.h
@@ -420,6 +420,26 @@ inline qasymm8_t qasymm8_leaky_relu(qasymm8_t                      in,
     return tmp;
 }
 
+inline qasymm8_t qasymm8_logistic(qasymm8_t                      in,
+                                  const UniformQuantizationInfo &qi_in,
+                                  const UniformQuantizationInfo &qi_out)
+{
+    float tmp_f         = dequantize_qasymm8(in, qi_in);
+    tmp_f               = 1.f / (1.f + std::exp(-tmp_f));
+    const qasymm8_t tmp = quantize_qasymm8(tmp_f, qi_out);
+    return tmp;
+}
+
+inline qasymm8_signed_t qasymm8_signed_logistic(qasymm8_signed_t               in,
+                                                const UniformQuantizationInfo &qi_in,
+                                                const UniformQuantizationInfo &qi_out)
+{
+    float tmp_f                = dequantize_qasymm8_signed(in, qi_in);
+    tmp_f                      = 1.f / (1.f + std::exp(-tmp_f));
+    const qasymm8_signed_t tmp = quantize_qasymm8_signed(tmp_f, qi_out);
+    return tmp;
+}
+
 /** Dequantize a value given a 8-bit symmetric quantization scheme
  *
  * @param[in] value Value to dequantize