ip_test.go

     1  // Copyright 2026 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build goexperiment.simd
     6  
     7  package simd_test
     8  
     9  import (
    10  	"fmt"
    11  	"simd"
    12  	"testing"
    13  )
    14  
    15  func TestIP(t *testing.T) {
    16  
    17  	var a, b [50]float32
    18  	for i := 0; i < 50; i++ {
    19  		a[i] = float32(i)
    20  		b[i] = float32(i)
    21  	}
    22  	x, sumWidth, emulated := ip(a[:50], b[:50])
    23  
    24  	if x != 40425 {
    25  		t.Errorf("Expected 40425, got %f", x)
    26  	}
    27  
    28  	fmt.Printf("ip: sum was computed in width %d, emulated = %v\n", sumWidth, emulated)
    29  }
    30  
    31  func TestIPGoTo(t *testing.T) {
    32  
    33  	var a, b [50]float32
    34  	for i := 0; i < 50; i++ {
    35  		a[i] = float32(i)
    36  		b[i] = float32(i)
    37  	}
    38  	x, sumWidth, emulated := ipGoTo(a[:50], b[:50])
    39  
    40  	if x != 40425 {
    41  		t.Errorf("Expected 40425, got %f", x)
    42  	}
    43  
    44  	fmt.Printf("ipgoto: sum was computed in width %d, emulated = %v\n", sumWidth, emulated)
    45  }
    46  
    47  func first[T, U any](t T, u U) T {
    48  	return t
    49  }
    50  
    51  func ip(x, y []float32) (float32, int, bool) {
    52  	var a simd.Float32s
    53  	sumWidth := a.Len() * 32
    54  	emulated := simd.Emulated()
    55  	var i int
    56  	for i = 0; i < len(x)-a.Len()+1; i += a.Len() {
    57  		u := simd.LoadFloat32s(x[i : i+a.Len()])
    58  		v := simd.LoadFloat32s(y[i : i+a.Len()])
    59  		a = a.Add(u.Mul(v))
    60  	}
    61  	if i < len(x) {
    62  		a = a.Add(first(simd.LoadFloat32sPart(x[i:])).
    63  			Mul(first(simd.LoadFloat32sPart(y[i:]))))
    64  	}
    65  
    66  	return sum(a), sumWidth, emulated
    67  }
    68  
    69  func ipGoTo(x, y []float32) (float32, int, bool) {
    70  	var a simd.Float32s
    71  	sumWidth := a.Len() * 32
    72  	emulated := simd.Emulated()
    73  	var i int
    74  	var u, v simd.Float32s
    75  loop:
    76  	if !(i < len(x)-a.Len()+1) {
    77  		goto done
    78  	}
    79  	u = simd.LoadFloat32s(x[i : i+a.Len()])
    80  	v = simd.LoadFloat32s(y[i : i+a.Len()])
    81  	a = a.Add(u.Mul(v))
    82  	i += a.Len()
    83  	goto loop
    84  done:
    85  	if i < len(x) {
    86  		a = a.Add(first(simd.LoadFloat32sPart(x[i:])).
    87  			Mul(first(simd.LoadFloat32sPart(y[i:]))))
    88  	}
    89  
    90  	return sum(a), sumWidth, emulated
    91  }
    92  
    93  func boringSum(x simd.Float32s) float32 {
    94  	s := make([]float32, x.Len())
    95  	x.Store(s)
    96  	var r float32
    97  	for _, e := range s {
    98  		r += e
    99  	}
   100  	return r
   101  }
   102
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