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Branchless Programming: Difference between revisions
→Multiplications
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==Multiplications== | ==Multiplications== | ||
Multiplications by booleans can be used instead of switch statements. | |||
Rather than doing | Rather than doing | ||
< | <syntaxhighlight lang="python"> | ||
if age > 10: | if age > 10: | ||
x = x + 10 | x = x + 10 | ||
else: | else: | ||
x = x - 10 | x = x - 10 | ||
</ | </syntaxhighlight> | ||
you can do | you can do | ||
< | <syntaxhighlight> | ||
y = 2 * (age > 10) - 1 | y = 2 * (age > 10) - 1 | ||
x = x + 10 * y | x = x + 10 * y | ||
| Line 58: | Line 60: | ||
y = age > 10 | y = age > 10 | ||
x = x + 10 * y - 10 * (1-y) | x = x + 10 * y - 10 * (1-y) | ||
</ | </syntaxhighlight> | ||
These are micro optimizations but they are sometimes useful for speeding up GPU shaders. | These are micro optimizations but they are sometimes useful for speeding up GPU shaders. | ||