vec: some useful functions (#103)

These functions are added:
- abs(): absolute value
- fract(): fractional part
- norm_one(): L1 norm
- norm_inf(): infinity norm
- hadd(): horizontal add
- hmax(): horizontal max

include/cglm/simd/arm.h

@@ -13,6 +13,12 @@
 #define glmm_load(p)      vld1q_f32(p)
 #define glmm_store(p, a)  vst1q_f32(p, a)
 
+static inline
+float32x4_t
+glmm_abs(float32x4_t v) {
+  return vabsq_f32(v);
+}
+
 static inline
 float
 glmm_hadd(float32x4_t v) {
@@ -25,6 +31,22 @@ glmm_hadd(float32x4_t v) {
 #endif
 }
 
+static inline
+float
+glmm_hmin(float32x4_t v) {
+  v = vpmin_f32(vget_low_f32(v), vget_high_f32(v));
+  v = vpmin_f32(v, v);
+  return vget_lane_f32(v, 0);
+}
+
+static inline
+float
+glmm_hmax(float32x4_t v) {
+  v = vpmax_f32(vget_low_f32(v), vget_high_f32(v));
+  v = vpmax_f32(v, v);
+  return vget_lane_f32(v, 0);
+}
+
 static inline
 float
 glmm_dot(float32x4_t a, float32x4_t b) {
@@ -43,5 +65,17 @@ glmm_norm2(float32x4_t a) {
   return glmm_dot(a, a);
 }
 
+static inline
+float
+glmm_norm_one(float32x4_t a) {
+  return glmm_hadd(glmm_abs(a));
+}
+
+static inline
+float
+glmm_norm_inf(float32x4_t a) {
+  return glmm_hmax(glmm_abs(a));
+}
+
 #endif
 #endif /* cglm_simd_arm_h */