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+## Using afl++ without inlined instrumentation
+
+  This file describes how you can disable inlining of instrumentation.
+
+
+By default, the GCC plugin will duplicate the effects of calling
+`__afl_trace` (see `afl-gcc-rt.o.c`) in instrumented code, instead of
+issuing function calls.
+
+The calls are presumed to be slower, more so because the rt file
+itself is not optimized by the compiler.
+
+Setting `AFL_GCC_OUT_OF_LINE=1` in the environment while compiling code
+with the plugin will disable this inlining, issuing calls to the
+unoptimized runtime instead.
+
+You probably don't want to do this, but it might be useful in certain
+AFL debugging scenarios, and it might work as a fallback in case
+something goes wrong with the inlined instrumentation.