diff --git a/src/cmd/5g/ggen.c b/src/cmd/5g/ggen.c
index 840d55a95c..40ef0bd7bc 100644
--- a/src/cmd/5g/ggen.c
+++ b/src/cmd/5g/ggen.c
@@ -543,6 +543,7 @@ cgen_shift(int op, int bounded, Node *nl, Node *nr, Node *res)
 	Type *tr;
 	uvlong sc;
 
+	USED(bounded);
 	if(nl->type->width > 4)
 		fatal("cgen_shift %T", nl->type);
 
diff --git a/src/cmd/5g/reg.c b/src/cmd/5g/reg.c
index 14cda51488..5f7ed2e88d 100644
--- a/src/cmd/5g/reg.c
+++ b/src/cmd/5g/reg.c
@@ -207,7 +207,6 @@ regopt(Prog *firstp)
 		return;
 	}
 
-	r1 = R;
 	firstr = R;
 	lastr = R;
 
diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index f62c927e24..1937d899ab 100644
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -913,6 +913,7 @@ asmb(void)
 			}
 			phsh(pnote, sh);
 		}
+		USED(resoff);
 
 		elfphload(&segtext);
 		elfphload(&segdata);
diff --git a/src/cmd/ld/pe.c b/src/cmd/ld/pe.c
index d263562aec..f2903ba0f9 100644
--- a/src/cmd/ld/pe.c
+++ b/src/cmd/ld/pe.c
@@ -536,6 +536,7 @@ addexcept(IMAGE_SECTION_HEADER *text)
 	uvlong n;
 	Sym *sym;
 
+	USED(text);
 	if(thechar != '6')
 		return;