Kernel: Add `[[unlikely]]` attribute to VERIFY

This optimization has already been done in LibC's `assert.h`, which
Userland `VERIFY()` calls resolve to. We now use it in the kernel, but
with the nicer C++ *unlikely* attribute instead of `__builtin_expect`.

This tells the compiler to arrange the generated machine code so that
the error-free branches execute faster (e.g. fewer jumps, better cache
locality).

1 files changed, 6 insertions, 1 deletions

diff --git a/Kernel/Assertions.h b/Kernel/Assertions.h
index 932e497301..436f13a989 100644
--- a/Kernel/Assertions.h
+++ b/Kernel/Assertions.h
@@ -10,7 +10,12 @@
 #define __STRINGIFY(x) __STRINGIFY_HELPER(x)
 
 [[noreturn]] void __assertion_failed(const char* msg, const char* file, unsigned line, const char* func);
-#define VERIFY(expr) (static_cast<bool>(expr) ? void(0) : __assertion_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__))
+#define VERIFY(expr)                                                            \
+    do {                                                                        \
+        if (!static_cast<bool>(expr)) [[unlikely]]                              \
+            __assertion_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+    } while (0)
+
 #define VERIFY_NOT_REACHED() VERIFY(false)
 
 extern "C" {