bug2.go

     1  // compile
     2  
     3  //go:build amd64 && goexperiment.simd
     4  
     5  // Copyright 2025 The Go Authors. All rights reserved.
     6  // Use of this source code is governed by a BSD-style
     7  // license that can be found in the LICENSE file.
     8  
     9  // Test case for rematerialization ignoring the register constraint
    10  // during regalloc's shuffle phase.
    11  
    12  package p
    13  
    14  import (
    15  	"simd"
    16  )
    17  
    18  func PackComplex(b bool) {
    19  	for {
    20  		if b {
    21  			var indices [4]uint32
    22  			simd.Uint32x4{}.ShiftAllRight(20).Store(&indices)
    23  			_ = indices[indices[0]]
    24  		}
    25  	}
    26  }
    27  
    28  func PackComplex2(x0 uint16, src [][4]float32, b, b2 bool) {
    29  	var out [][4]byte
    30  	if b2 {
    31  		for y := range x0 {
    32  			row := out[:x0]
    33  			for x := range row {
    34  				px := &src[y]
    35  				if b {
    36  					var indices [4]uint32
    37  					fu := simd.LoadFloat32x4(px).AsUint32x4()
    38  					fu.ShiftAllRight(0).Store(nil)
    39  					entry := simd.LoadUint32x4(&[4]uint32{
    40  						toSrgbTable[indices[0]],
    41  					})
    42  					var res [4]uint32
    43  					entry.ShiftAllRight(19).Store(nil)
    44  					row[x] = [4]uint8{
    45  						uint8(res[0]),
    46  						uint8(res[1]),
    47  						uint8(res[2]),
    48  					}
    49  				} else {
    50  					row[x] = [4]uint8{
    51  						float32ToSrgb8(0),
    52  						float32ToSrgb8(1),
    53  						float32ToSrgb8(2),
    54  					}
    55  				}
    56  			}
    57  			out = out[len(out):]
    58  		}
    59  	}
    60  }
    61  
    62  var toSrgbTable = [4]uint32{}
    63  
    64  func float32ToSrgb8(f float32) uint8 {
    65  	f = min(0, f)
    66  	fu := uint32(f)
    67  	entry := toSrgbTable[fu]
    68  	return uint8(entry * fu)
    69  }
    70
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