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go/test/mergemul.go
Cholerae Hu fb165eaffd cmd/compile: combine x*n - y*n into (x-y)*n
Do the similar thing to CL 55143 to reduce IMUL.

Change-Id: I1bd38f618058e3cd74fac181f003610ea13f2294
Reviewed-on: https://go-review.googlesource.com/56252
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-09-03 14:29:38 +00:00

118 lines
3.2 KiB
Go

// runoutput
// Copyright 2017 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 main
import "fmt"
// Check that expressions like (c*n + d*(n+k)) get correctly merged by
// the compiler into (c+d)*n + d*k (with c+d and d*k computed at
// compile time).
//
// The merging is performed by a combination of the multiplication
// merge rules
// (c*n + d*n) -> (c+d)*n
// and the distributive multiplication rules
// c * (d+x) -> c*d + c*x
// Generate a MergeTest that looks like this:
//
// a8, b8 = m1*n8 + m2*(n8+k), (m1+m2)*n8 + m2*k
// if a8 != b8 {
// // print error msg and panic
// }
func makeMergeAddTest(m1, m2, k int, size string) string {
model := " a" + size + ", b" + size
model += fmt.Sprintf(" = %%d*n%s + %%d*(n%s+%%d), (%%d+%%d)*n%s + (%%d*%%d)", size, size, size)
test := fmt.Sprintf(model, m1, m2, k, m1, m2, m2, k)
test += fmt.Sprintf(`
if a%s != b%s {
fmt.Printf("MergeAddTest(%d, %d, %d, %s) failed\n")
fmt.Printf("%%d != %%d\n", a%s, b%s)
panic("FAIL")
}
`, size, size, m1, m2, k, size, size, size)
return test + "\n"
}
// Check that expressions like (c*n - d*(n+k)) get correctly merged by
// the compiler into (c-d)*n - d*k (with c-d and d*k computed at
// compile time).
//
// The merging is performed by a combination of the multiplication
// merge rules
// (c*n - d*n) -> (c-d)*n
// and the distributive multiplication rules
// c * (d-x) -> c*d - c*x
// Generate a MergeTest that looks like this:
//
// a8, b8 = m1*n8 - m2*(n8+k), (m1-m2)*n8 - m2*k
// if a8 != b8 {
// // print error msg and panic
// }
func makeMergeSubTest(m1, m2, k int, size string) string {
model := " a" + size + ", b" + size
model += fmt.Sprintf(" = %%d*n%s - %%d*(n%s+%%d), (%%d-%%d)*n%s - (%%d*%%d)", size, size, size)
test := fmt.Sprintf(model, m1, m2, k, m1, m2, m2, k)
test += fmt.Sprintf(`
if a%s != b%s {
fmt.Printf("MergeSubTest(%d, %d, %d, %s) failed\n")
fmt.Printf("%%d != %%d\n", a%s, b%s)
panic("FAIL")
}
`, size, size, m1, m2, k, size, size, size)
return test + "\n"
}
func makeAllSizes(m1, m2, k int) string {
var tests string
tests += makeMergeAddTest(m1, m2, k, "8")
tests += makeMergeAddTest(m1, m2, k, "16")
tests += makeMergeAddTest(m1, m2, k, "32")
tests += makeMergeAddTest(m1, m2, k, "64")
tests += makeMergeSubTest(m1, m2, k, "8")
tests += makeMergeSubTest(m1, m2, k, "16")
tests += makeMergeSubTest(m1, m2, k, "32")
tests += makeMergeSubTest(m1, m2, k, "64")
tests += "\n"
return tests
}
func main() {
fmt.Println(`package main
import "fmt"
var n8 int8 = 42
var n16 int16 = 42
var n32 int32 = 42
var n64 int64 = 42
func main() {
var a8, b8 int8
var a16, b16 int16
var a32, b32 int32
var a64, b64 int64
`)
fmt.Println(makeAllSizes(03, 05, 0)) // 3*n + 5*n
fmt.Println(makeAllSizes(17, 33, 0))
fmt.Println(makeAllSizes(80, 45, 0))
fmt.Println(makeAllSizes(32, 64, 0))
fmt.Println(makeAllSizes(7, 11, +1)) // 7*n + 11*(n+1)
fmt.Println(makeAllSizes(9, 13, +2))
fmt.Println(makeAllSizes(11, 16, -1))
fmt.Println(makeAllSizes(17, 9, -2))
fmt.Println("}")
}