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// runoutput
// Copyright 2016 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.
// Generate test of strength reduction for multiplications
// with constants. Especially useful for amd64/386.
package main
import "fmt"
func testMul(fact, bits int) string {
n := fmt.Sprintf("testMul_%d_%d", fact, bits)
fmt.Printf("func %s(s int%d) {\n", n, bits)
want := 0
for i := 0; i < 200; i++ {
fmt.Printf(` if want, got := int%d(%d), s*%d; want != got {
failed = true
fmt.Printf("got %d * %%d == %%d, wanted %d\n", s, got)
}
`, bits, want, i, i, want)
want += fact
}
fmt.Printf("}\n")
return fmt.Sprintf("%s(%d)", n, fact)
}
func main() {
fmt.Printf("package main\n")
fmt.Printf("import \"fmt\"\n")
fmt.Printf("var failed = false\n")
f1 := testMul(17, 32)
f2 := testMul(131, 64)
fmt.Printf("func main() {\n")
fmt.Println(f1)
fmt.Println(f2)
fmt.Printf("if failed {\n panic(\"multiplication failed\")\n}\n")
fmt.Printf("}\n")
}
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