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go/test/intrinsic.dir/main.go
David Chase 8eec2bbfbc cmd/compile: added some intrinsics to SSA back end
One intrinsic was needed to help get the very best
performance out of a future GC; as long as that one was
being added, I also added Bswap since that is sometimes
a handy thing to have.  I had intended to fill out the
bit-scan intrinsic family, but the mismatch between the
"scan forward" instruction and "count leading zeroes"
was large enough to cause me to leave it out -- it poses
a dilemma that I'd rather dodge right now.

These intrinsics are not exposed for general use.
That's a separate issue requiring an API proposal change
( https://github.com/golang/proposal )

All intrinsics are tested, both that they are substituted
on the appropriate architecture, and that they produce the
expected result.

Change-Id: I5848037cfd97de4f75bdc33bdd89bba00af4a8ee
Reviewed-on: https://go-review.googlesource.com/20564
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-28 16:29:59 +00:00

110 lines
2.8 KiB
Go

// 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.
package main
import (
"fmt"
T "runtime/internal/sys"
)
var A = []uint64{0x0102030405060708, 0x1122334455667788}
var B = []uint64{0x0807060504030201, 0x8877665544332211}
var errors int
func logf(f string, args ...interface{}) {
errors++
fmt.Printf(f, args...)
if errors > 100 { // 100 is enough spewage
panic("100 errors is plenty is enough")
}
}
func test(i, x uint64) {
t := T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
if i != t {
logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
}
x = -x
t = T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
if i != t {
logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
}
if i <= 32 {
x32 := uint32(x)
t32 := T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
if uint32(i) != t32 {
logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
}
x32 = -x32
t32 = T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
if uint32(i) != t32 {
logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
}
}
if i <= 16 {
x16 := uint16(x)
t16 := T.Ctz16(x16) // ERROR "intrinsic substitution for Ctz16"
if uint16(i) != t16 {
logf("Ctz16(0x%x) expected %d but got %d\n", x16, i, t16)
}
x16 = -x16
t16 = T.Ctz16(x16) // ERROR "intrinsic substitution for Ctz16"
if uint16(i) != t16 {
logf("Ctz16(0x%x) expected %d but got %d\n", x16, i, t16)
}
}
}
func main() {
// Test Bswap first because the other test relies on it
// working correctly (to implement bit reversal).
for i := range A {
x := A[i]
y := B[i]
X := T.Bswap64(x) // ERROR "intrinsic substitution for Bswap64"
Y := T.Bswap64(y) // ERROR "intrinsic substitution for Bswap64"
if y != X {
logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", x, y, X)
}
if x != Y {
logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", y, x, Y)
}
x32 := uint32(X)
y32 := uint32(Y >> 32)
X32 := T.Bswap32(x32) // ERROR "intrinsic substitution for Bswap32"
Y32 := T.Bswap32(y32) // ERROR "intrinsic substitution for Bswap32"
if y32 != X32 {
logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", x32, y32, X32)
}
if x32 != Y32 {
logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", y32, x32, Y32)
}
}
// Zero is a special case, be sure it is done right.
if T.Ctz16(0) != 16 { // ERROR "intrinsic substitution for Ctz16"
logf("ctz16(0) != 16")
}
if T.Ctz32(0) != 32 { // ERROR "intrinsic substitution for Ctz32"
logf("ctz32(0) != 32")
}
if T.Ctz64(0) != 64 { // ERROR "intrinsic substitution for Ctz64"
logf("ctz64(0) != 64")
}
for i := uint64(0); i <= 64; i++ {
for j := uint64(1); j <= 255; j += 2 {
for k := uint64(1); k <= 65537; k += 128 {
x := (j * k) << i
test(i, x)
}
}
}
}