...
Run Format

Source file test/strength.go

Documentation: test

  // 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 contstants. 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")
  }
  

View as plain text