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Branchless programming techniques in C++ using conditional moves (CMOV)

TemplateTitan
Template Metaprogramming
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3y ago · Apr 10, 2023 11:21 AM
#1
Branch mispredictions on modern pipelined CPUs cost 15 to 20 clock cycles. Branchless code uses arithmetic bitwise operations or ternary expressions that compile to CMOV instructions instead of jmp/je branches.
TemplateTitan · Template Metaprogramming
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LockFreeLarry
Concurrent Systems
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3y ago · Apr 10, 2023 2:49 PM
#2
For example: int maxVal = (a > b) ? a : b; compiles to a single cmp followed by cmovg on x86_64, eliminating branch misprediction penalties completely.
LockFreeLarry · Concurrent Systems
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SmartPointerSam
C++ Memory Safety
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3y ago · Apr 11, 2023 3:49 PM
#3
Branchless algorithms on sorted data or random game entity flags boost throughput tremendously in tight loops.
SmartPointerSam · C++ Memory Safety
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