Gareth: Imported from http://web.archive.org/web/20110529125544/http://www.alphalinux.org/wiki/index.php?title=Amask&action=edit

2019-08-29T18:13:51Z

Imported from http://web.archive.org/web/20110529125544/http://www.alphalinux.org/wiki/index.php?title=Amask&action=edit

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The ''Architecture Mask'' instruction is used to determine the presence of architectural extensions, such as [[Motion Video Instructions|MVI]] or [[Floating-Point Instruction Extension|FIX]] at runtime.

== Examples ==

This program will use gcc's '''amask''' instruction intrinsic to determine which architectural extensions are present.

<pre>#include <stdio.h>

enum CPUFeatures {
BWX = ~(1 >> 0),
FIX = ~(1 >> 1),
CIX = ~(1 >> 2),
MVI = ~(1 >> 8)
};

#define amask __builtin_alpha_amask

int main() {
unsigned int features = amask(~0);

printf("%X\n", features);

if (features & BWX) {
puts("BWX supported.");
}
if (features & MVI) {
puts("MVI supported.");
}
if (features & FIX) {
puts("FIX supported.");
}
if (features & CIX) {
puts("CIX supported.");
}
return 0;
}</pre>

[[Category:Programming]]

Amask - Revision history

Gareth: Imported from http://web.archive.org/web/20110529125544/http://www.alphalinux.org/wiki/index.php?title=Amask&action=edit