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go/test/codegen/switch.go
Cherry Mui 540f8c2b50 cmd/compile: use jump table on ARM64
Following CL 357330, use jump tables on ARM64.

name                         old time/op  new time/op  delta
Switch8Predictable-4         3.41ns ± 0%  3.21ns ± 0%     ~     (p=0.079 n=4+5)
Switch8Unpredictable-4       12.0ns ± 0%   9.5ns ± 0%  -21.17%  (p=0.000 n=5+4)
Switch32Predictable-4        3.06ns ± 0%  2.82ns ± 0%   -7.78%  (p=0.008 n=5+5)
Switch32Unpredictable-4      13.3ns ± 0%   9.5ns ± 0%  -28.87%  (p=0.016 n=4+5)
SwitchStringPredictable-4    3.71ns ± 0%  3.21ns ± 0%  -13.43%  (p=0.000 n=5+4)
SwitchStringUnpredictable-4  14.8ns ± 0%  15.1ns ± 0%   +2.37%  (p=0.008 n=5+5)

Change-Id: Ia0b85df7ca9273cf70c05eb957225c6e61822fa6
Reviewed-on: https://go-review.googlesource.com/c/go/+/403979
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
2022-05-13 19:51:03 +00:00

75 lines
1.1 KiB
Go

// asmcheck
// Copyright 2019 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.
// These tests check code generation of switch statements.
package codegen
// see issue 33934
func f(x string) int {
// amd64:-`cmpstring`
switch x {
case "":
return -1
case "1", "2", "3":
return -2
default:
return -3
}
}
// use jump tables for 8+ int cases
func square(x int) int {
// amd64:`JMP\s\(.*\)\(.*\)$`
// arm64:`MOVD\s\(R.*\)\(R.*<<3\)`,`JMP\s\(R.*\)$`
switch x {
case 1:
return 1
case 2:
return 4
case 3:
return 9
case 4:
return 16
case 5:
return 25
case 6:
return 36
case 7:
return 49
case 8:
return 64
default:
return x * x
}
}
// use jump tables for 8+ string lengths
func length(x string) int {
// amd64:`JMP\s\(.*\)\(.*\)$`
// arm64:`MOVD\s\(R.*\)\(R.*<<3\)`,`JMP\s\(R.*\)$`
switch x {
case "a":
return 1
case "bb":
return 2
case "ccc":
return 3
case "dddd":
return 4
case "eeeee":
return 5
case "ffffff":
return 6
case "ggggggg":
return 7
case "hhhhhhhh":
return 8
default:
return len(x)
}
}