refactor: namespace npy_float_math → numpy::detail

Merge npy_math_float.h functions into numpy::detail namespace
(same as svml_bridge.h). Both internal headers now share
numpy::detail — applications must never use numpy::detail::*.

Public API remains numpy::* from core.h.

Author: peng.li24

numpy/npy_math_float.h

@@ -1,6 +1,9 @@
 // INTERNAL HEADER — DO NOT INCLUDE DIRECTLY.
 // Use #include "numpy/core.h" which pulls this in automatically.
 //
+// All functions live in numpy::detail — do not call directly.
+// Use numpy::exp() etc. from core.h.
+//
 // Bit-exact float32 math matching numpy 1.23.5 SIMD polynomial approximations.
 // Replicates numpy's simd_exp_FLOAT, simd_log_FLOAT, simd_sincos_f32 algorithms.
 
@@ -11,7 +14,10 @@
 #include <cmath>
 
 namespace numpy {
-namespace npy_float_math {
+namespace detail {
+// Float32 bit-exact polynomial approximations — internal detail, do not use directly.
+// These replicate numpy's simd_exp_FLOAT, simd_log_FLOAT, simd_sincos_f32 algorithms.
+// Public API: use numpy::exp() etc. from core.h.
 
 namespace {
 
@@ -279,5 +285,5 @@ inline float npy_cosf(float x) {
 }
 
 } // anonymous namespace
-} // namespace npy_float_math
+} // namespace detail
 } // namespace numpy

numpy/svml_bridge.h

@@ -168,10 +168,10 @@ NUMPY_NPY_F64(exp2,  std::exp2(x))
 // f32 exp/log/sin/cos: numpy's own polynomial approximations (npy_math_float.h)
 // are the canonical implementation for float32. dlsym npy_expf/etc. would
 // resolve a different (non-matching) code path. Never use dlsym for these.
-inline float exp_npy_f32(float x)  { return npy_float_math::npy_expf(x); }
-inline float log_npy_f32(float x)  { return npy_float_math::npy_logf(x); }
-inline float sin_npy_f32(float x)  { return npy_float_math::npy_sinf(x); }
-inline float cos_npy_f32(float x)  { return npy_float_math::npy_cosf(x); }
+inline float exp_npy_f32(float x)  { return npy_expf(x); }
+inline float log_npy_f32(float x)  { return npy_logf(x); }
+inline float sin_npy_f32(float x)  { return npy_sinf(x); }
+inline float cos_npy_f32(float x)  { return npy_cosf(x); }
 NUMPY_NPY_F32(tan,   std::tan(x))
 NUMPY_NPY_F32(asin,  std::asin(x))
 NUMPY_NPY_F32(acos,  std::acos(x))