tests/spec/intel_shader_atomic_float_minmax/execution/ssbo-atomicCompSwap-float-NaN.shader_test

   1 [require]
   2 GL >= 3.3
   3 GLSL >= 3.30
   4 GL_ARB_shader_storage_buffer_object
   5 GL_INTEL_shader_atomic_float_minmax
   6
   7 [vertex shader passthrough]
   8
   9 [fragment shader]
  10 #extension GL_ARB_shader_storage_buffer_object: require
  11 #extension GL_INTEL_shader_atomic_float_minmax: require
  12
  13 layout(binding = 0) buffer bufblock {
  14         float value[8];
  15 };
  16
  17 #define POS_NAN(x) (0x7f800000u | (0x007fffffu & uint(x)))
  18 #define NEG_NAN(x) (0xff800000u | (0x007fffffu & uint(x)))
  19
  20 uniform uint comparitors[] = uint[](POS_NAN(0x00ffffff),
  21                                     NEG_NAN(0x00ffffff),
  22                                     POS_NAN(0x00555555),
  23                                     NEG_NAN(0x00555555),
  24                                     POS_NAN(0x00aaaaaa),
  25                                     NEG_NAN(0x00aaaaaa),
  26                                     floatBitsToUint(0.0),
  27                                     floatBitsToUint(1.0));
  28
  29 out vec4 color;
  30
  31 void main()
  32 {
  33         uint idx = uint(gl_FragCoord.x + gl_FragCoord.y) % uint(value.length());
  34
  35         /* This compare-and-swap should never succeed because NaN is never
  36          * equal to anything.  Either the value in the SSBO or the value being
  37          * compared is NaN.  If the compare-and-swap succeeds, the SSBO
  38          * element will forever be set to float(idx).
  39          */
  40         atomicCompSwap(value[idx],
  41                        uintBitsToFloat(comparitors[idx]),
  42                        42.0);
  43
  44         color = value[idx] == 42.0
  45                 ? vec4(1.0, 0.0, 0.0, 1.0)
  46                 : vec4(0.0, 1.0, 0.0, 1.0);
  47 }
  48
  49 [test]
  50 ssbo 0 32
  51 ssbo 0 subdata int  0 0x7fffffff
  52 ssbo 0 subdata int  4 0xffffffff
  53 ssbo 0 subdata int  8 0x7fd55555
  54 ssbo 0 subdata int 12 0xffd55555
  55 ssbo 0 subdata float 16 0.0
  56 ssbo 0 subdata float 20 1.0
  57 ssbo 0 subdata int 24 0x7faaaaaa
  58 ssbo 0 subdata int 28 0xffaaaaaa
  59
  60 clear color 0.5 0.5 0.5 0.5
  61 clear
  62
  63 draw rect -1 -1 2 2
  64 probe all rgba 0.0 1.0 0.0 1.0