[-Wall -W -Wextra -pipe -Wno-long-long -Wvla -Wno-overlength-strings -Wunsafe-loop-optimizations -Wundef -Wformat=2 -Wlogical-op -Wsign-compare -Wformat-security -Wmissing-include-dirs -Wformat-nonliteral -Wold-style-definition -Wpointer-arith -Winit-self -Wdeclaration-after-statement -Wfloat-equal -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wmissing-declarations -Wmissing-noreturn -Wshadow -Wendif-labels -Wcast-align -Wstrict-aliasing -Wwrite-strings -Wno-unused-parameter -ffast-math -Wp,-D_FORTIFY_SOURCE=2 -fno-common -fdiagnostics-show-option],
[], [-pedantic -Werror])
+# Only enable fastpath asserts when doing a debug build, e.g. from bootstrap.sh.
+AS_CASE([" $CFLAGS "], [*" -O0 "*], [], [AX_APPEND_FLAG(["-DFASTPATH"], [CPPFLAGS])])
+
#### Linker flags ####