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go/test/inline_endian.go

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cmd/compile: make encoding/binary loads/stores cheaper to inline The encoding/binary little- and big-endian load and store routines are frequently used in performance sensitive code. They look fairly complex to the inliner. Though the routines themselves can be inlined, code using them typically cannot be. Yet they typically compile down to an instruction or two on architectures that support merging such loads. This change teaches the inliner to treat calls to these methods as cheap, so that code using them will be more inlineable. It'd be better to teach the inliner that this pattern of code is cheap, rather than these particular methods. However, that is difficult to do robustly when working with the IR representation. And the broader project of which that would be a part, namely to model the rest of the compiler in the inliner, is probably a non-starter. By way of contrast, imperfect though it is, this change is an easy, cheap, and useful heuristic. If/when we base inlining decisions on more accurate information obtained later in the compilation process, or on PGO/FGO, we can remove this and other such heuristics. Newly inlineable functions in the standard library: crypto/cipher.gcmInc32 crypto/sha512.appendUint64 crypto/md5.appendUint64 crypto/sha1.appendUint64 crypto/sha256.appendUint64 vendor/golang.org/x/crypto/poly1305.initialize encoding/gob.(*encoderState).encodeUint vendor/golang.org/x/text/unicode/norm.buildRecompMap net/http.(*http2SettingsFrame).Setting net/http.http2parseGoAwayFrame net/http.http2parseWindowUpdateFrame Benchmark impact for encoding/gob (the only package I measured): name old time/op new time/op delta EndToEndPipe-8 2.25µs ± 1% 2.21µs ± 3% -1.79% (p=0.000 n=28+27) EndToEndByteBuffer-8 93.3ns ± 5% 94.2ns ± 5% ~ (p=0.174 n=30+30) EndToEndSliceByteBuffer-8 10.5µs ± 1% 10.6µs ± 1% +0.87% (p=0.000 n=30+30) EncodeComplex128Slice-8 1.81µs ± 0% 1.75µs ± 1% -3.23% (p=0.000 n=28+30) EncodeFloat64Slice-8 900ns ± 1% 847ns ± 0% -5.91% (p=0.000 n=29+28) EncodeInt32Slice-8 1.02µs ± 0% 0.90µs ± 0% -11.82% (p=0.000 n=28+26) EncodeStringSlice-8 1.16µs ± 1% 1.04µs ± 1% -10.20% (p=0.000 n=29+26) EncodeInterfaceSlice-8 28.7µs ± 3% 29.2µs ± 6% ~ (p=0.067 n=29+30) DecodeComplex128Slice-8 7.98µs ± 1% 7.96µs ± 1% -0.27% (p=0.017 n=30+30) DecodeFloat64Slice-8 4.33µs ± 1% 4.34µs ± 1% +0.24% (p=0.022 n=30+29) DecodeInt32Slice-8 4.18µs ± 1% 4.18µs ± 0% ~ (p=0.074 n=30+28) DecodeStringSlice-8 13.2µs ± 1% 13.1µs ± 1% -0.64% (p=0.000 n=28+28) DecodeStringsSlice-8 31.9µs ± 1% 31.8µs ± 1% -0.34% (p=0.001 n=30+30) DecodeBytesSlice-8 8.88µs ± 1% 8.84µs ± 1% -0.48% (p=0.000 n=30+30) DecodeInterfaceSlice-8 64.1µs ± 1% 64.2µs ± 1% ~ (p=0.173 n=30+28) DecodeMap-8 74.3µs ± 0% 74.2µs ± 0% ~ (p=0.131 n=29+30) Fixes #42958 Change-Id: Ie048b8976fb403d8bcc72ac6bde4b33e133e2a47 Reviewed-on: https://go-review.googlesource.com/c/go/+/349931 Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2021-09-13 16:28:55 -06:00
// errorcheckwithauto -0 -m -d=inlfuncswithclosures=1
//go:build (386 || amd64 || arm64 || ppc64le || s390x) && !gcflags_noopt
cmd/compile: make encoding/binary loads/stores cheaper to inline The encoding/binary little- and big-endian load and store routines are frequently used in performance sensitive code. They look fairly complex to the inliner. Though the routines themselves can be inlined, code using them typically cannot be. Yet they typically compile down to an instruction or two on architectures that support merging such loads. This change teaches the inliner to treat calls to these methods as cheap, so that code using them will be more inlineable. It'd be better to teach the inliner that this pattern of code is cheap, rather than these particular methods. However, that is difficult to do robustly when working with the IR representation. And the broader project of which that would be a part, namely to model the rest of the compiler in the inliner, is probably a non-starter. By way of contrast, imperfect though it is, this change is an easy, cheap, and useful heuristic. If/when we base inlining decisions on more accurate information obtained later in the compilation process, or on PGO/FGO, we can remove this and other such heuristics. Newly inlineable functions in the standard library: crypto/cipher.gcmInc32 crypto/sha512.appendUint64 crypto/md5.appendUint64 crypto/sha1.appendUint64 crypto/sha256.appendUint64 vendor/golang.org/x/crypto/poly1305.initialize encoding/gob.(*encoderState).encodeUint vendor/golang.org/x/text/unicode/norm.buildRecompMap net/http.(*http2SettingsFrame).Setting net/http.http2parseGoAwayFrame net/http.http2parseWindowUpdateFrame Benchmark impact for encoding/gob (the only package I measured): name old time/op new time/op delta EndToEndPipe-8 2.25µs ± 1% 2.21µs ± 3% -1.79% (p=0.000 n=28+27) EndToEndByteBuffer-8 93.3ns ± 5% 94.2ns ± 5% ~ (p=0.174 n=30+30) EndToEndSliceByteBuffer-8 10.5µs ± 1% 10.6µs ± 1% +0.87% (p=0.000 n=30+30) EncodeComplex128Slice-8 1.81µs ± 0% 1.75µs ± 1% -3.23% (p=0.000 n=28+30) EncodeFloat64Slice-8 900ns ± 1% 847ns ± 0% -5.91% (p=0.000 n=29+28) EncodeInt32Slice-8 1.02µs ± 0% 0.90µs ± 0% -11.82% (p=0.000 n=28+26) EncodeStringSlice-8 1.16µs ± 1% 1.04µs ± 1% -10.20% (p=0.000 n=29+26) EncodeInterfaceSlice-8 28.7µs ± 3% 29.2µs ± 6% ~ (p=0.067 n=29+30) DecodeComplex128Slice-8 7.98µs ± 1% 7.96µs ± 1% -0.27% (p=0.017 n=30+30) DecodeFloat64Slice-8 4.33µs ± 1% 4.34µs ± 1% +0.24% (p=0.022 n=30+29) DecodeInt32Slice-8 4.18µs ± 1% 4.18µs ± 0% ~ (p=0.074 n=30+28) DecodeStringSlice-8 13.2µs ± 1% 13.1µs ± 1% -0.64% (p=0.000 n=28+28) DecodeStringsSlice-8 31.9µs ± 1% 31.8µs ± 1% -0.34% (p=0.001 n=30+30) DecodeBytesSlice-8 8.88µs ± 1% 8.84µs ± 1% -0.48% (p=0.000 n=30+30) DecodeInterfaceSlice-8 64.1µs ± 1% 64.2µs ± 1% ~ (p=0.173 n=30+28) DecodeMap-8 74.3µs ± 0% 74.2µs ± 0% ~ (p=0.131 n=29+30) Fixes #42958 Change-Id: Ie048b8976fb403d8bcc72ac6bde4b33e133e2a47 Reviewed-on: https://go-review.googlesource.com/c/go/+/349931 Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2021-09-13 16:28:55 -06:00
// Copyright 2021 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.
// Similar to inline.go, but only for architectures that can merge loads.
package foo
import (
"encoding/binary"
)
// Ensure that simple encoding/binary functions are cheap enough
// that functions using them can also be inlined (issue 42958).
func endian(b []byte) uint64 { // ERROR "can inline endian" "b does not escape"
return binary.LittleEndian.Uint64(b) + binary.BigEndian.Uint64(b) // ERROR "inlining call to binary.littleEndian.Uint64" "inlining call to binary.bigEndian.Uint64"
}
func appendLittleEndian(b []byte) []byte { // ERROR "can inline appendLittleEndian" "leaking param: b to result ~r0 level=0"
b = binary.LittleEndian.AppendUint64(b, 64) // ERROR "inlining call to binary.littleEndian.AppendUint64"
b = binary.LittleEndian.AppendUint32(b, 32) // ERROR "inlining call to binary.littleEndian.AppendUint32"
b = binary.LittleEndian.AppendUint16(b, 16) // ERROR "inlining call to binary.littleEndian.AppendUint16"
return b
}
func appendBigEndian(b []byte) []byte { // ERROR "can inline appendBigEndian" "leaking param: b to result ~r0 level=0"
b = binary.BigEndian.AppendUint64(b, 64) // ERROR "inlining call to binary.bigEndian.AppendUint64"
b = binary.BigEndian.AppendUint32(b, 32) // ERROR "inlining call to binary.bigEndian.AppendUint32"
b = binary.BigEndian.AppendUint16(b, 16) // ERROR "inlining call to binary.bigEndian.AppendUint16"
return b
}