diff --git a/src/backend/utils/adt/encode.c b/src/backend/utils/adt/encode.c
index 7ba92c2c481..eb932d4bd8a 100644
--- a/src/backend/utils/adt/encode.c
+++ b/src/backend/utils/adt/encode.c
@@ -317,6 +317,9 @@ static inline bool
 hex_decode_simd_helper(const Vector8 src, Vector8 *dst)
 {
 	Vector8		sub;
+	// TODO: set one and use bitwise NOT for the other
+	Vector8		maskupper = vector8_set(0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0);
+	Vector8		masklower = vector8_set(0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff, 0, 0xff);
 	Vector8		msk;
 	bool		ret;
 
@@ -334,9 +337,9 @@ hex_decode_simd_helper(const Vector8 src, Vector8 *dst)
 	*dst = vector8_issub(src, sub);
 	ret = !vector8_has_ge(*dst, 0x10);
 
-	msk = vector8_and(*dst, vector8_broadcast_u32(0xff00ff00));
+	msk = vector8_and(*dst, masklower);
 	msk = vector8_shift_right_byte(msk);
-	*dst = vector8_and(*dst, vector8_broadcast_u32(0x00ff00ff));
+	*dst = vector8_and(*dst, maskupper);
 	*dst = vector8_shift_left_nibble(*dst);
 	*dst = vector8_or(*dst, msk);
 	return ret;
diff --git a/src/include/port/simd.h b/src/include/port/simd.h
index 531d8b8b6d1..56e810ce081 100644
--- a/src/include/port/simd.h
+++ b/src/include/port/simd.h
@@ -101,6 +101,33 @@ static inline Vector8 vector8_min(const Vector8 v1, const Vector8 v2);
 static inline Vector32 vector32_eq(const Vector32 v1, const Vector32 v2);
 #endif
 
+/*
+ * Populate a vector element-wise with the arguments.
+ */
+#ifndef USE_NO_SIMD
+#if defined(USE_NEON)
+// from a patch by Thomas Munro
+static inline Vector8
+vector8_set(uint8 v0, uint8 v1, uint8 v2, uint8 v3,
+	 uint8 v4, uint8 v5, uint8 v6, uint8 v7,
+	 uint8 v8, uint8 v9, uint8 v10, uint8 v11,
+	 uint8 v12, uint8 v13, uint8 v14, uint8 v15)
+{
+	uint8 pg_attribute_aligned(16) values[16] = {
+		v0, v1, v2, v3,
+		v4, v5, v6, v7,
+		v8, v9, v10, v11,
+		v12, v13, v14, v15
+	};
+	return vld1q_u8(values);
+}
+#elif defined(USE_SSE2)
+#ifndef vector8_set
+#define vector8_set(...)		_mm_setr_epi8(__VA_ARGS__)
+#endif
+#endif
+#endif							/* ! USE_NO_SIMD */
+
 /*
  * Load a chunk of memory into the given vector.
  */
@@ -368,6 +395,7 @@ vector8_highbit_mask(const Vector8 v)
 	 * returns a uint64, making it inconvenient to combine mask values from
 	 * multiple vectors.
 	 */
+	// TODO: use vector8_set
 	static const uint8 mask[16] = {
 		1 << 0, 1 << 1, 1 << 2, 1 << 3,
 		1 << 4, 1 << 5, 1 << 6, 1 << 7,