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Update popcnt16-popcnt-popcnt64.md #793

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Update popcnt16-popcnt-popcnt64.md
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4 changes: 2 additions & 2 deletions docs/intrinsics/popcnt16-popcnt-popcnt64.md
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Expand Up @@ -9,7 +9,7 @@ ms.assetid: e525b236-adc8-42df-9b9b-8b7d8c245d3b

**Microsoft Specific**

Counts the number of one bits (population count) in a 16-, 32-, or 64-byte unsigned integer.
Counts the number of one bits (population count) in a 16-, 32-, or 64-bit unsigned integer.

## Syntax

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## Remarks

Each of these intrinsics generates the `popcnt` instruction. The size of the value that the `popcnt` instruction returns is the same as the size of its argument. In 32-bit mode there are no 64-bit general-purpose registers, hence no 64-bit `popcnt`.
Each of these intrinsics generates the `popcnt` instruction. In 32-bit mode there are no 64-bit general-purpose registers, hence no 64-bit `popcnt`.

To determine hardware support for the `popcnt` instruction, call the `__cpuid` intrinsic with `InfoType=0x00000001` and check bit 23 of `CPUInfo[2] (ECX)`. This bit is 1 if the instruction is supported, and 0 otherwise. If you run code that uses this intrinsic on hardware that does not support the `popcnt` instruction, the results are unpredictable.

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