Quieten gcc for tatuological comparisons.

src/libre/dialect/Makefile

@@ -41,6 +41,14 @@ DFLAGS.${src} += -I src # XXX: for internal.h
 ACT.${parser} = src/libre/parser.act
 .endfor
 
+# Our inlined actions use m < n for counts, but are also called with
+# m for both values, and gcc complains about m < m never being true.
+.if ${CC:T:Mgcc}
+.for src in ${SRC:Msrc/libre/dialect/${dialect}/parser.c}
+CFLAGS.${src} += -Wno-tautological-compare
+.endfor
+.endif
+
 # SID persistent variables are unused in some productions
 .if ${CC:T:Mgcc} || ${CC:T:Mclang}
 .for src in ${SRC:Msrc/libre/dialect/${dialect}/parser.c}