Add utility functions for SVE

- Few bit-width dependent intrinsics are added.
- Few math functions are added.

Partially implements: COMPMID-3872

Change-Id: Ia6ab46bd170fec9c7c8d4410b7ef4d84710b68ed
Signed-off-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4718
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 132 insertions, 69 deletions

diff --git a/src/core/NEON/SVEMath.inl b/src/core/NEON/SVEMath.inl
index 5ebfeaa5c5..86592f6dc3 100644
--- a/src/core/NEON/SVEMath.inl
+++ b/src/core/NEON/SVEMath.inl
@@ -26,6 +26,10 @@
 
 #if defined(__ARM_FEATURE_SVE)
 
+#ifndef M_PI
+#define M_PI (3.14159265358979323846)
+#endif // M_PI
+
 namespace arm_compute
 {
 inline svfloat32_t svtaylor_poly_f32_z(svbool_t pg, svfloat32_t x, const std::array<svfloat32_t, 8> &coeffs)
@@ -115,47 +119,23 @@ inline svfloat32_t svexp_f32_z(svbool_t pg, svfloat32_t x)
 
 inline svfloat16_t svexp_f16_z(svbool_t pg, svfloat16_t x)
 {
-    const auto CONST_LN2          = svdup_n_f16(0.6931471805f); // ln(2)
-    const auto CONST_INV_LN2      = svdup_n_f16(1.4426950408f); // 1/ln(2)
-    const auto CONST_INF          = svdup_n_f16(std::numeric_limits<float16_t>::infinity());
-    const auto CONST_MAX_INPUT    = svdup_n_f16(88.7f);
-    const auto CONST_0            = svdup_n_f16(0.f);
-    const auto CONST_NEGATIVE_126 = svdup_n_s16(-126);
-
-    /** Exponent polynomial coefficients */
-    const std::array<svfloat16_t, 8> exp_tab =
-    {
-        {
-            svdup_n_f16(1.f),
-            svdup_n_f16(0.0416598916054f),
-            svdup_n_f16(0.500000596046f),
-            svdup_n_f16(0.0014122662833f),
-            svdup_n_f16(1.00000011921f),
-            svdup_n_f16(0.00833693705499f),
-            svdup_n_f16(0.166665703058f),
-            svdup_n_f16(0.000195780929062f),
-        }
-    };
-
-    // Perform range reduction [-log(2),log(2)]
-    auto m   = svcvt_s16_f16_z(pg, svmul_f16_z(pg, x, CONST_INV_LN2));
-    auto val = svmls_f16_z(pg, x, svcvt_f16_s16_z(pg, m), CONST_LN2);
-
-    // Polynomial Approximation
-    auto poly = svtaylor_poly_f16_z(pg, val, exp_tab);
-
-    // Reconstruct
-    poly = svreinterpret_f16_s16(svqadd_s16(svreinterpret_s16_f16(poly), svlsl_n_s16_z(pg, m, 11)));
-
-    // Handle underflow
-    svbool_t ltpg = svcmplt_s16(pg, m, CONST_NEGATIVE_126);
-    poly          = svsel_f16(ltpg, CONST_0, poly);
+    auto bottom = svcvt_f32_z(pg, x);
+#if defined(__ARM_FEATURE_SVE2)
+    auto top    = svcvtlt_f32_x(pg, x);
+    auto pg_top = pg;
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    auto pg_top = svptrue_b16();
+    auto top    = svcvt_f32_z(pg_top, svreinterpret_f16(svrevh_z(svptrue_b16(), svreinterpret_u32(x))));
+#endif /* defined(__ARM_FEATURE_SVE2) */
 
-    // Handle overflow
-    svbool_t gtpg = svcmpgt_f16(pg, x, CONST_MAX_INPUT);
-    poly          = svsel_f16(gtpg, CONST_INF, poly);
+    bottom = svexp_f32_z(pg, bottom);
+    top    = svexp_f32_z(pg_top, top);
 
-    return poly;
+#if defined(__ARM_FEATURE_SVE2)
+    return svcvtnt_f16_m(svcvt_f16_z(pg, bottom), pg_top, top);
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    return svtrn1(svcvt_f16_z(pg, bottom), svcvt_f16_z(pg_top, top));
+#endif /* defined(__ARM_FEATURE_SVE2) */
 }
 
 inline svfloat32_t svtanh_f32_z(svbool_t pg, svfloat32_t val)
@@ -190,9 +170,6 @@ inline svfloat16_t svtanh_f16_z(svbool_t pg, svfloat16_t val)
 
 inline svfloat32_t svlog_f32_z(svbool_t pg, svfloat32_t x)
 {
-#if defined(__ARM_FEATURE_SVE2)
-    return svcvt_f32_s32_z(pg, svlogb_f32_z(pg, x));
-#else  /* !defined(__ARM_FEATURE_SVE2) */
     /** Logarithm polynomial coefficients */
     const std::array<svfloat32_t, 8> log_tab =
     {
@@ -222,45 +199,131 @@ inline svfloat32_t svlog_f32_z(svbool_t pg, svfloat32_t x)
     poly = svmla_f32_z(pg, poly, svcvt_f32_s32_z(pg, m), CONST_LN2);
 
     return poly;
-#endif /* defined(__ARM_FEATURE_SVE2) */
 }
 
 inline svfloat16_t svlog_f16_z(svbool_t pg, svfloat16_t x)
 {
+    auto bottom = svcvt_f32_z(pg, x);
 #if defined(__ARM_FEATURE_SVE2)
-    return svcvt_f16_s16_z(pg, svlogb_f16_z(pg, x));
-#else  /* !defined(__ARM_FEATURE_SVE2) */
+    auto top    = svcvtlt_f32_x(pg, x);
+    auto pg_top = pg;
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    auto pg_top = svptrue_b16();
+    auto top    = svcvt_f32_z(pg_top, svreinterpret_f16(svrevh_z(svptrue_b16(), svreinterpret_u32(x))));
+#endif /* defined(__ARM_FEATURE_SVE2) */
 
-    /** Logarithm polynomial coefficients */
-    const std::array<svfloat16_t, 8> log_tab
-    {
-        {
-            svdup_n_f16(-2.29561495781f),
-            svdup_n_f16(-2.47071170807f),
-            svdup_n_f16(-5.68692588806f),
-            svdup_n_f16(-0.165253549814f),
-            svdup_n_f16(5.17591238022f),
-            svdup_n_f16(0.844007015228f),
-            svdup_n_f16(4.58445882797f),
-            svdup_n_f16(0.0141278216615f),
-        }
-    };
+    bottom = svlog_f32_z(pg, bottom);
+    top    = svlog_f32_z(pg_top, top);
 
-    const auto CONST_7   = svdup_n_s16(7);             // 7
-    const auto CONST_LN2 = svdup_n_f16(0.6931471805f); // ln(2)
+#if defined(__ARM_FEATURE_SVE2)
+    return svcvtnt_f16_m(svcvt_f16_z(pg, bottom), pg_top, top);
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    return svtrn1(svcvt_f16_z(pg, bottom), svcvt_f16_z(pg_top, top));
+#endif /* defined(__ARM_FEATURE_SVE2) */
+}
 
-    // Extract exponent
-    auto m   = svsub_s16_z(pg, svasr_n_s16_z(pg, svreinterpret_s16_f16(x), 11), CONST_7);
-    auto val = svreinterpret_f16_s16(svsub_s16_z(pg, svreinterpret_s16_f16(x), svlsl_n_s16_z(pg, m, 11)));
+inline svfloat32_t svsin_f32_z(svbool_t pg, svfloat32_t val)
+{
+    using ScalarType = float;
+    using IntType    = u32;
 
-    // Polynomial Approximation
-    auto poly = svtaylor_poly_f16_z(pg, val, log_tab);
+    constexpr float te_sin_coeff2 = 0.166666666666f; // 1/(2*3)
+    constexpr float te_sin_coeff3 = 0.05f;           // 1/(4*5)
+    constexpr float te_sin_coeff4 = 0.023809523810f; // 1/(6*7)
+    constexpr float te_sin_coeff5 = 0.013888888889f; // 1/(8*9)
 
-    // Reconstruct
-    poly = svmla_f16_z(pg, poly, svcvt_f16_s16_z(pg, m), CONST_LN2);
+    const auto pi_v   = wrapper::svdup_n(ScalarType(M_PI));
+    const auto pio2_v = wrapper::svdup_n(ScalarType(M_PI / 2));
+    const auto ipi_v  = wrapper::svdup_n(ScalarType(1 / M_PI));
 
-    return poly;
+    //Find positive or negative
+    const auto c_v    = svabs_z(pg, wrapper::svcvt_z<int32_t>(pg, svmul_z(pg, val, ipi_v)));
+    const auto sign_v = svcmple(pg, val, wrapper::svdup_n(ScalarType(0)));
+    const auto odd_v  = svcmpne(pg, svand_z(pg, wrapper::svreinterpret<IntType>(c_v), wrapper::svdup_n(IntType(1))), wrapper::svdup_n(IntType(0)));
+
+    auto neg_v = sveor_z(pg, odd_v, sign_v);
+
+    //Modulus a - (n * int(a*(1/n)))
+    auto       ma    = svsub_z(pg, svabs_z(pg, val), svmul_z(pg, pi_v, wrapper::svcvt_z<ScalarType>(pg, c_v)));
+    const auto reb_v = svcmpge(pg, ma, pio2_v);
+
+    //Rebase a between 0 and pi/2
+    ma = svsel(reb_v, svsub_z(pg, pi_v, ma), ma);
+
+    //Taylor series
+    const auto ma2 = svmul_z(pg, ma, ma);
+
+    //2nd elem: x^3 / 3!
+    auto elem = svmul_z(pg, svmul_z(pg, ma, ma2), wrapper::svdup_n(ScalarType(te_sin_coeff2)));
+    auto res  = svsub_z(pg, ma, elem);
+
+    //3rd elem: x^5 / 5!
+    elem = svmul_z(pg, svmul_z(pg, elem, ma2), wrapper::svdup_n(ScalarType(te_sin_coeff3)));
+    res  = svadd_z(pg, res, elem);
+
+    //4th elem: x^7 / 7!float32x2_t vsin_f32(float32x2_t val)
+    elem = svmul_z(pg, svmul_z(pg, elem, ma2), wrapper::svdup_n(ScalarType(te_sin_coeff4)));
+    res  = svsub_z(pg, res, elem);
+
+    //5th elem: x^9 / 9!
+    elem = svmul_z(pg, svmul_z(pg, elem, ma2), wrapper::svdup_n(ScalarType(te_sin_coeff5)));
+    res  = svadd_z(pg, res, elem);
+
+    //Change of sign
+    res = svneg_m(res, neg_v, res);
+    return res;
+}
+
+inline svfloat16_t svsin_f16_z(svbool_t pg, svfloat16_t val)
+{
+    auto bottom = svcvt_f32_z(pg, val);
+#if defined(__ARM_FEATURE_SVE2)
+    auto top    = svcvtlt_f32_x(pg, val);
+    auto pg_top = pg;
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    auto pg_top = svptrue_b16();
+    auto top    = svcvt_f32_z(pg_top, svreinterpret_f16(svrevh_z(svptrue_b16(), svreinterpret_u32(val))));
+#endif /* defined(__ARM_FEATURE_SVE2) */
+
+    bottom = svsin_f32_z(pg, bottom);
+    top    = svsin_f32_z(pg_top, top);
+
+#if defined(__ARM_FEATURE_SVE2)
+    return svcvtnt_f16_m(svcvt_f16_z(pg, bottom), pg_top, top);
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    return svtrn1(svcvt_f16_z(pg, bottom), svcvt_f16_z(pg_top, top));
 #endif /* defined(__ARM_FEATURE_SVE2) */
 }
+
+inline svfloat32_t svpow_f32_z(svbool_t pg, svfloat32_t a, svfloat32_t b)
+{
+    return svexp_f32_z(pg, svmul_z(pg, b, svlog_f32_z(pg, a)));
+}
+
+inline svfloat16_t svpow_f16_z(svbool_t pg, svfloat16_t a, svfloat16_t b)
+{
+    auto a_bottom = svcvt_f32_z(pg, a);
+    auto b_bottom = svcvt_f32_z(pg, b);
+
+#if defined(__ARM_FEATURE_SVE2)
+    auto pg_top = pg;
+    auto a_top  = svcvtlt_f32_x(pg, a);
+    auto b_top  = svcvtlt_f32_x(pg, b)
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    auto pg_top = svptrue_b16();
+    auto a_top  = svcvt_f32_z(pg_top, svreinterpret_f16(svrevh_z(svptrue_b16(), svreinterpret_u32(a))));
+    auto b_top  = svcvt_f32_z(pg_top, svreinterpret_f16(svrevh_z(svptrue_b16(), svreinterpret_u32(b))));
+#endif /* defined(__ARM_FEATURE_SVE2) */
+
+                  auto res_bottom = svpow_f32_z(pg, a_bottom, b_bottom);
+    auto     res_top    = svpow_f32_z(pg_top, a_top, b_top);
+
+#if defined(__ARM_FEATURE_SVE2)
+    return svcvtnt_f16_m(svcvt_f16_z(pg, res_bottom), pg_top, res_top);
+#else  /* defined(__ARM_FEATURE_SVE2) */
+    return svtrn1(svcvt_f16_z(pg, res_bottom), svcvt_f16_z(pg_top, res_top));
+#endif /* defined(__ARM_FEATURE_SVE2) */
+}
+
 } // namespace arm_compute
 #endif /* defined(__ARM_FEATURE_SVE) */