#Pragma Roll

What this C++ compiler-directive question tests

This is a straightforward easy question on C++ language knowledge that appears in technical interviews at firms like Nvidia, where candidates work directly with compiler optimizations and performance-critical code. It tests whether you understand how to communicate intent to the compiler and what practical effect such directives have on generated machine code.

Candidates are expected to explain what the directive does, when you might use it, and how it influences the compiler's code generation. The answer requires familiarity with loop optimization techniques and the tradeoffs between code size, execution speed, and compilation time. This is particularly relevant in GPU programming and high-performance C++ where manual tuning of compiler behaviour is common.

• Loop unrolling and its performance implications
• Compiler pragmas and their scope
• Code-size versus latency tradeoffs