mirror of
https://github.com/golang/go
synced 2024-11-18 08:44:43 -07:00
3e270ab80b
Now that we have ops that can return 2 results, have BSF return a result
and flags. We can then get rid of the redundant comparison and use CMOV
instead of CMOVconst ops.
Get rid of a bunch of the ops we don't use. Ctz{8,16}, plus all the Clzs,
and CMOVNEs. I don't think we'll ever use them, and they would be easy
to add back if needed.
Change-Id: I8858a1d017903474ea7e4002fc76a6a86e7bd487
Reviewed-on: https://go-review.googlesource.com/27630
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
95 lines
2.4 KiB
Go
95 lines
2.4 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"fmt"
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T "runtime/internal/sys"
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)
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var A = []uint64{0x0102030405060708, 0x1122334455667788}
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var B = []uint64{0x0807060504030201, 0x8877665544332211}
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var errors int
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func logf(f string, args ...interface{}) {
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errors++
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fmt.Printf(f, args...)
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if errors > 100 { // 100 is enough spewage
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panic("100 errors is plenty is enough")
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}
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}
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func test(i, x uint64) {
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t := T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
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if i != t {
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logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
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}
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x = -x
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t = T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
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if i != t {
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logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
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}
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if i <= 32 {
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x32 := uint32(x)
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t32 := T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
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if uint32(i) != t32 {
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logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
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}
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x32 = -x32
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t32 = T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
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if uint32(i) != t32 {
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logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
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}
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}
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}
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func main() {
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// Test Bswap first because the other test relies on it
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// working correctly (to implement bit reversal).
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for i := range A {
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x := A[i]
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y := B[i]
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X := T.Bswap64(x) // ERROR "intrinsic substitution for Bswap64"
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Y := T.Bswap64(y) // ERROR "intrinsic substitution for Bswap64"
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if y != X {
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logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", x, y, X)
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}
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if x != Y {
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logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", y, x, Y)
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}
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x32 := uint32(X)
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y32 := uint32(Y >> 32)
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X32 := T.Bswap32(x32) // ERROR "intrinsic substitution for Bswap32"
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Y32 := T.Bswap32(y32) // ERROR "intrinsic substitution for Bswap32"
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if y32 != X32 {
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logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", x32, y32, X32)
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}
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if x32 != Y32 {
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logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", y32, x32, Y32)
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}
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}
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// Zero is a special case, be sure it is done right.
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if T.Ctz32(0) != 32 { // ERROR "intrinsic substitution for Ctz32"
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logf("ctz32(0) != 32")
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}
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if T.Ctz64(0) != 64 { // ERROR "intrinsic substitution for Ctz64"
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logf("ctz64(0) != 64")
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}
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for i := uint64(0); i <= 64; i++ {
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for j := uint64(1); j <= 255; j += 2 {
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for k := uint64(1); k <= 65537; k += 128 {
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x := (j * k) << i
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test(i, x)
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}
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}
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}
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}
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