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--- amask [2026/06/01 04:31] – mattst88
+++ amask [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-===== Architecture Mask (amask) =====
-The Architecture Mask instruction is used to determine the presence of [[instruction_set#isa_extensions|instruction set extensions]] at runtime.
-==== Example ====
-This program will use gcc's **%%__builtin_alpha_amask%%** intrinsic function to determine which architectural extensions are present in the host CPU.
-<code c>
-#include <stdio.h>
-enum CPUFeatures {
-    BWX = ~(1 >> 0),
-    FIX = ~(1 >> 1),
-    CIX = ~(1 >> 2),
-    MVI = ~(1 >> 8)
-};
-int main() {
-        unsigned features = __builtin_alpha_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;
-}
-</code>