src/cmd/compile/internal/test/math_test.go

// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package test

import (
	"testing"
)

var Output int

func BenchmarkDiv64UnsignedSmall(b *testing.B) {
	q := uint64(1)
	for i := 1; i <= b.N; i++ {
		q = (q + uint64(i)) / uint64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64Small(b *testing.B) {
	q := int64(1)
	for i := 1; i <= b.N; i++ {
		q = (q + int64(i)) / int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64SmallNegDivisor(b *testing.B) {
	q := int64(-1)
	for i := 1; i <= b.N; i++ {
		q = (int64(i) - q) / -int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64SmallNegDividend(b *testing.B) {
	q := int64(-1)
	for i := 1; i <= b.N; i++ {
		q = -(int64(i) - q) / int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64SmallNegBoth(b *testing.B) {
	q := int64(1)
	for i := 1; i <= b.N; i++ {
		q = -(int64(i) + q) / -int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64Unsigned(b *testing.B) {
	q := uint64(1)
	for i := 1; i <= b.N; i++ {
		q = (uint64(0x7fffffffffffffff) - uint64(i) - (q & 1)) / uint64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64(b *testing.B) {
	q := int64(1)
	for i := 1; i <= b.N; i++ {
		q = (int64(0x7fffffffffffffff) - int64(i) - (q & 1)) / int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64NegDivisor(b *testing.B) {
	q := int64(-1)
	for i := 1; i <= b.N; i++ {
		q = (int64(0x7fffffffffffffff) - int64(i) - (q & 1)) / -int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64NegDividend(b *testing.B) {
	q := int64(-1)
	for i := 1; i <= b.N; i++ {
		q = -(int64(0x7fffffffffffffff) - int64(i) - (q & 1)) / int64(i)
	}
	Output = int(q)
}

func BenchmarkDiv64NegBoth(b *testing.B) {
	q := int64(-1)
	for i := 1; i <= b.N; i++ {
		q = -(int64(0x7fffffffffffffff) - int64(i) - (q & 1)) / -int64(i)
	}
	Output = int(q)
}

func BenchmarkMod64UnsignedSmall(b *testing.B) {
	r := uint64(1)
	for i := 1; i <= b.N; i++ {
		r = (uint64(i) + r) % uint64(i)
	}
	Output = int(r)
}

func BenchmarkMod64Small(b *testing.B) {
	r := int64(1)
	for i := 1; i <= b.N; i++ {
		r = (int64(i) + r) % int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64SmallNegDivisor(b *testing.B) {
	r := int64(-1)
	for i := 1; i <= b.N; i++ {
		r = (int64(i) - r) % -int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64SmallNegDividend(b *testing.B) {
	r := int64(-1)
	for i := 1; i <= b.N; i++ {
		r = -(int64(i) - r) % int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64SmallNegBoth(b *testing.B) {
	r := int64(1)
	for i := 1; i <= b.N; i++ {
		r = -(int64(i) + r) % -int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64Unsigned(b *testing.B) {
	r := uint64(1)
	for i := 1; i <= b.N; i++ {
		r = (uint64(0x7fffffffffffffff) - uint64(i) - (r & 1)) % uint64(i)
	}
	Output = int(r)
}

func BenchmarkMod64(b *testing.B) {
	r := int64(1)
	for i := 1; i <= b.N; i++ {
		r = (int64(0x7fffffffffffffff) - int64(i) - (r & 1)) % int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64NegDivisor(b *testing.B) {
	r := int64(-1)
	for i := 1; i <= b.N; i++ {
		r = (int64(0x7fffffffffffffff) - int64(i) - (r & 1)) % -int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64NegDividend(b *testing.B) {
	r := int64(-1)
	for i := 1; i <= b.N; i++ {
		r = -(int64(0x7fffffffffffffff) - int64(i) - (r & 1)) % int64(i)
	}
	Output = int(r)
}

func BenchmarkMod64NegBoth(b *testing.B) {
	r := int64(1)
	for i := 1; i <= b.N; i++ {
		r = -(int64(0x7fffffffffffffff) - int64(i) - (r & 1)) % -int64(i)
	}
	Output = int(r)
}

// BenchmarkDiv32UnsignedConstOdd benchmarks uint32 division by odd constants
// whose magic multiplier is truly 33-bit (m&1 != 0): divisors 7, 19, 107.
// On 64-bit targets this exercises the pre-shifted Hmul64u optimization.
func BenchmarkDiv32UnsignedConstOdd(b *testing.B) {
	var ret uint32 = 1
	for i := 0; i < b.N; i++ {
		x := uint32(i) ^ ret
		ret ^= x / 7
		ret ^= x / 19
		ret ^= x / 107
	}
	Output = int(ret)
}

// BenchmarkDiv32UnsignedConstEven benchmarks uint32 division by even constants
// whose magic multiplier is truly 33-bit (m&1 != 0): divisors 14, 38, 214.
// These are of the form 2*d where d is an odd divisor with 33-bit magic.
func BenchmarkDiv32UnsignedConstEven(b *testing.B) {
	var ret uint32 = 1
	for i := 0; i < b.N; i++ {
		x := uint32(i) ^ ret
		ret ^= x / 14
		ret ^= x / 38
		ret ^= x / 214
	}
	Output = int(ret)
}