diff --git a/std/crc32/common_crc32.wuffs b/std/crc32/common_crc32.wuffs
index ee3470e..aaec989 100644
--- a/std/crc32/common_crc32.wuffs
+++ b/std/crc32/common_crc32.wuffs
@@ -69,29 +69,6 @@
 	this.state = 0xFFFF_FFFF ^ s
 }
 
-pri func ieee_hasher.up_arm_crc32!(x: slice base.u8),
-	choose cpu_arch >= arm_crc32,
-{
-	var s : base.arm_crc32_u32
-	var p : slice base.u8
-
-	s = s.create(a: 0xFFFF_FFFF ^ this.state)
-
-	// Align to a 16-byte boundary.
-	while (args.x.length() > 0) and ((15 & args.x.uintptr_low_12_bits()) <> 0) {
-		s = s._crc32b(b: args.x[0])
-		args.x = args.x[1 ..]
-	} endwhile
-
-	iterate (p = args.x)(length: 8, advance: 8, unroll: 16) {
-		s = s._crc32d(b: p.peek_u64le())
-	} else (length: 1, advance: 1, unroll: 1) {
-		s = s._crc32b(b: p[0])
-	}
-
-	this.state = 0xFFFF_FFFF ^ s.value()
-}
-
 // The table below was created by script/print-crc32-magic-numbers.go.
 
 pri const IEEE_TABLE : array[16] array[256] base.u32 = [[
diff --git a/std/crc32/common_up_arm_crc32.wuffs b/std/crc32/common_up_arm_crc32.wuffs
new file mode 100644
index 0000000..fcd5d36
--- /dev/null
+++ b/std/crc32/common_up_arm_crc32.wuffs
@@ -0,0 +1,36 @@
+// Copyright 2021 The Wuffs Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+pri func ieee_hasher.up_arm_crc32!(x: slice base.u8),
+	choose cpu_arch >= arm_crc32,
+{
+	var s : base.arm_crc32_u32
+	var p : slice base.u8
+
+	s = s.create(a: 0xFFFF_FFFF ^ this.state)
+
+	// Align to a 16-byte boundary.
+	while (args.x.length() > 0) and ((15 & args.x.uintptr_low_12_bits()) <> 0) {
+		s = s._crc32b(b: args.x[0])
+		args.x = args.x[1 ..]
+	} endwhile
+
+	iterate (p = args.x)(length: 8, advance: 8, unroll: 16) {
+		s = s._crc32d(b: p.peek_u64le())
+	} else (length: 1, advance: 1, unroll: 1) {
+		s = s._crc32b(b: p[0])
+	}
+
+	this.state = 0xFFFF_FFFF ^ s.value()
+}