ISLESSGREATER(3clc)

✨ ISLESSGREATER — the OpenCL manual page, bestie edition ✨

okay so this is islessgreater from the OpenCL Manual, section 3clc, and it's literally just "is x less than y OR is x greater than y" and honestly? iconic. it's the "are these two NOT equal" girlie of the relational function family. 💅

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🌸 NAME 🌸

islessgreater — Compare of (x < y) || (x > y).

the whole fam, in all their flavors:

int islessgreater(float x, float y);

intn islessgreater(floatn x, floatn y);

int islessgreater(double x, double y);

longn islessgreater(doublen x, doublen y);

int islessgreater (half x, half y)   //
if half extension enabled
shortn islessgreater (halfn x, halfn y)
// if half extension enabled

no cap, that half situation only shows up if the half extension is enabled. don't come for me, that's just what it says. 🫶

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💖 DESCRIPTION 💖

Returns the component-wise compare of (x < y) || (x > y).

like, for every component, it's asking "is this one less than that one, OR is it greater than that one?" and it answers per-component. so basically "are they different" but make it relational. 🔥

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🦋 NOTES 🦋

okay bestie, listen up, this part is important:

If an implementation extends this specification to support IEEE-754 flags or exceptions, then all built-in relational functions shall proceed without raising the invalid floating-point exception when one or more of the operands are NaNs. so NaNs walk in and nobody's throwing an invalid floating-point exception. periodt. 💀

The built-in relational functions are extended with cl_khr_fp16(3clc) to include appropriate versions of functions that take half, and half{2|3|4|8|16} as arguments and return values. so yeah, the half girls get their own versions. 🌸

The function returns a 0 if the specified relation is false and a 1 if the specified relation is true for scalar argument types. These functions shall return a 0 if the specified relation is false and a - 1 (i.e. all bits set) if the specified relation is true for vector argument types. so scalars get 0/1 and vectors get 0/-1, and that -1 is literally all bits set. know the difference, it matters. ✨

The relational functions isequal, isgreater, isgreaterequal, isless, islessequal, and islessgreater always return 0 if either argument is not a number (NaN). isnotequal returns 1 if one or both arguments are not a number (NaN) and the argument type is a scalar, and returns -1 if one or both arguments are not a number (NaN) and the argument type is a vector. so NaN behavior is different across the family, don't get it twisted. 🙈

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👑 SPECIFICATION 👑

OpenCL Specification[1]

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🌈 SEE ALSO 🌈

• relationalFunctions(3clc)

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💜 AUTHORS 💜

The Khronos Group

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🎀 COPYRIGHT 🎀

Copyright © 2007-2011 The Khronos Group Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.

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📚 NOTES (the footnote one, not the other one, iykyk) 📚

1. OpenCL Specification page 264, section 6.12.6 - Relational Functions

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and that's the whole page, bestie. 🫶 this one's from The Khronos Group, dated 01/14/2021, and it lives in the OpenCL Manual. go forth and compare responsibly. 💅✨