variants.go

     1  // Copyright 2026 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package variants
     6  
     7  // DO NOT EDIT WITHOUT READING THIS FIRST.
     8  
     9  // This file is shared by the simd bridge generator
    10  // and the compiler's midway tree rewriter.  The sharing
    11  // is facilitated by an automatic copy from the file
    12  // embedded in the simd bridge generator, which itself
    13  // copies it from its "variants" subdirectory.  To
    14  // change this file, edit the copy in
    15  // src/simd/archsimd/_gen/midway/variants/variants.go,
    16  // and then rerun ("go run") the simd bridge generator
    17  // and it will create a bridge consistent with the contents
    18  // of this file, for use with a compiler built to use this
    19  // file.  Minor version skews will only affect code
    20  // (e.g., rebuilding the compiler) that uses "simd"
    21  // (not "archsimd") and that runs on hardware lacking
    22  // the expected feature set.  In the worst case,
    23  // GODEBUG=simd=0 will avoid the problem, unless it
    24  // involves missing emulation methods (which you are
    25  // expected to write anyway if you are tinkering with
    26  // this code).
    27  
    28  type Key struct {
    29  	Arch string
    30  	Size int
    31  }
    32  
    33  type Variant struct {
    34  	Suffix          string          // the name (suffix) for this variant.
    35  	Emulated        map[string]bool // Methods that are emulated for this variant.
    36  	DefaultRequires string          // default requires this function return true, false means variant.
    37  }
    38  
    39  // Name returns the variant name of type t.
    40  // If receiver v is nil, returns t.
    41  func (v *Variant) Name(t string) string {
    42  	if v == nil {
    43  		return t
    44  	}
    45  	return t + v.Suffix
    46  }
    47  
    48  var Variants map[Key]*Variant
    49  
    50  func init() {
    51  	Variants = make(map[Key]*Variant)
    52  	Variants[Key{"arm64", 128}] = &Variant{
    53  		Suffix: "nclm",
    54  		Emulated: map[string]bool{
    55  			"CarrylessMultiplyEven": true,
    56  			"CarrylessMultiplyOdd":  true,
    57  		},
    58  		DefaultRequires: "HasHardwareCarrylessMultiply",
    59  	}
    60  
    61  }
    62
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