diff --git a/src/dsp/dec_msa.c b/src/dsp/dec_msa.c
index 8d9c98c3..cc1e2850 100644
--- a/src/dsp/dec_msa.c
+++ b/src/dsp/dec_msa.c
@@ -222,6 +222,7 @@ static void TransformAC3(const int16_t* in, uint8_t* dst) {
   const v16i8 cnst4b = __msa_ldi_b(4);                        \
   const v16i8 cnst3b = __msa_ldi_b(3);                        \
   const v8i16 cnst9h = __msa_ldi_h(9);                        \
+  const v8i16 cnst63h = __msa_ldi_h(63);                      \
                                                               \
   FLIP_SIGN4(p1, p0, q0, q1, p1_m, p0_m, q0_m, q1_m);         \
   filt = __msa_subs_s_b(p1_m, q1_m);                          \
@@ -241,9 +242,9 @@ static void TransformAC3(const int16_t* in, uint8_t* dst) {
   ILVRL_B2_SH(filt_sign, filt, filt_r, filt_l);               \
   /* update q2/p2 */                                          \
   temp0 = filt_r * cnst9h;                                    \
-  temp1 = ADDVI_H(temp0, 63);                                 \
+  temp1 = temp0 + cnst63h;                                    \
   temp2 = filt_l * cnst9h;                                    \
-  temp3 = ADDVI_H(temp2, 63);                                 \
+  temp3 = temp2 + cnst63h;                                    \
   FILT2(q2_m, p2_m, q2, p2);                                  \
   /* update q1/p1 */                                          \
   temp1 = temp1 + temp0;                                      \
@@ -708,7 +709,7 @@ static void VE4(uint8_t* dst) {    // vertical
   const uint32_t val0 = LW(ptop + 0);
   const uint32_t val1 = LW(ptop + 4);
   uint32_t out;
-  v16u8 A, B, C, AC, B2, R;
+  v16u8 A = { 0 }, B, C, AC, B2, R;
 
   INSERT_W2_UB(val0, val1, A);
   B = SLDI_UB(A, A, 1);
@@ -725,7 +726,7 @@ static void RD4(uint8_t* dst) {   // Down-right
   uint32_t val0 = LW(ptop + 0);
   uint32_t val1 = LW(ptop + 4);
   uint32_t val2, val3;
-  v16u8 A, B, C, AC, B2, R, A1;
+  v16u8 A, B, C, AC, B2, R, A1 = { 0 };
 
   INSERT_W2_UB(val0, val1, A1);
   A = SLDI_UB(A1, A1, 12);
@@ -753,7 +754,7 @@ static void LD4(uint8_t* dst) {   // Down-Left
   uint32_t val0 = LW(ptop + 0);
   uint32_t val1 = LW(ptop + 4);
   uint32_t val2, val3;
-  v16u8 A, B, C, AC, B2, R;
+  v16u8 A = { 0 }, B, C, AC, B2, R;
 
   INSERT_W2_UB(val0, val1, A);
   B = SLDI_UB(A, A, 1);
diff --git a/src/dsp/enc_msa.c b/src/dsp/enc_msa.c
index 909b46d5..d1c8bdf2 100644
--- a/src/dsp/enc_msa.c
+++ b/src/dsp/enc_msa.c
@@ -82,7 +82,7 @@ static void FTransform(const uint8_t* src, const uint8_t* ref, int16_t* out) {
   uint32_t in0, in1, in2, in3;
   v4i32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
   v8i16 t0, t1, t2, t3;
-  v16u8 srcl0, srcl1, src0, src1;
+  v16u8 srcl0, srcl1, src0 = { 0 }, src1 = { 0 };
   const v8i16 mask0 = { 0, 4, 8, 12, 1, 5, 9, 13 };
   const v8i16 mask1 = { 3, 7, 11, 15, 2, 6, 10, 14 };
   const v8i16 mask2 = { 4, 0, 5, 1, 6, 2, 7, 3 };
@@ -170,7 +170,7 @@ static void FTransformWHT(const int16_t* in, int16_t* out) {
 static int TTransform(const uint8_t* in, const uint16_t* w) {
   int sum;
   uint32_t in0_m, in1_m, in2_m, in3_m;
-  v16i8 src0;
+  v16i8 src0 = { 0 };
   v8i16 in0, in1, tmp0, tmp1, tmp2, tmp3;
   v4i32 dst0, dst1;
   const v16i8 zero = { 0 };
@@ -259,8 +259,9 @@ static void CollectHistogram(const uint8_t* ref, const uint8_t* pred,
 #define AVG2(a, b) (((a) + (b) + 1) >> 1)
 
 static WEBP_INLINE void VE4(uint8_t* dst, const uint8_t* top) {    // vertical
+  const v16u8 A1 = { 0 };
   const uint64_t val_m = LD(top - 1);
-  const v16u8 A = (v16u8)__msa_insert_d((v2i64)A, 0, val_m);
+  const v16u8 A = (v16u8)__msa_insert_d((v2i64)A1, 0, val_m);
   const v16u8 B = SLDI_UB(A, A, 1);
   const v16u8 C = SLDI_UB(A, A, 2);
   const v16u8 AC = __msa_ave_u_b(A, C);
@@ -292,8 +293,9 @@ static WEBP_INLINE void DC4(uint8_t* dst, const uint8_t* top) {
 }
 
 static WEBP_INLINE void RD4(uint8_t* dst, const uint8_t* top) {
+  const v16u8 A2 = { 0 };
   const uint64_t val_m = LD(top - 5);
-  const v16u8 A1 = (v16u8)__msa_insert_d((v2i64)A1, 0, val_m);
+  const v16u8 A1 = (v16u8)__msa_insert_d((v2i64)A2, 0, val_m);
   const v16u8 A = (v16u8)__msa_insert_b((v16i8)A1, 8, top[3]);
   const v16u8 B = SLDI_UB(A, A, 1);
   const v16u8 C = SLDI_UB(A, A, 2);
@@ -311,8 +313,9 @@ static WEBP_INLINE void RD4(uint8_t* dst, const uint8_t* top) {
 }
 
 static WEBP_INLINE void LD4(uint8_t* dst, const uint8_t* top) {
+  const v16u8 A1 = { 0 };
   const uint64_t val_m = LD(top);
-  const v16u8 A = (v16u8)__msa_insert_d((v2i64)A, 0, val_m);
+  const v16u8 A = (v16u8)__msa_insert_d((v2i64)A1, 0, val_m);
   const v16u8 B = SLDI_UB(A, A, 1);
   const v16u8 C1 = SLDI_UB(A, A, 2);
   const v16u8 C = (v16u8)__msa_insert_b((v16i8)C1, 6, top[7]);
@@ -645,7 +648,7 @@ static WEBP_INLINE void TrueMotion8x8(uint8_t* dst, const uint8_t* left,
 static WEBP_INLINE void DCMode8x8(uint8_t* dst, const uint8_t* left,
                                   const uint8_t* top) {
   uint64_t out;
-  v16u8 src;
+  v16u8 src = { 0 };
   if (top != NULL && left != NULL) {
     const uint64_t left_m = LD(left);
     const uint64_t top_m = LD(top);
@@ -777,7 +780,7 @@ static int SSE8x8(const uint8_t* a, const uint8_t* b) {
 static int SSE4x4(const uint8_t* a, const uint8_t* b) {
   uint32_t sum = 0;
   uint32_t src0, src1, src2, src3, ref0, ref1, ref2, ref3;
-  v16u8 src, ref, tmp0, tmp1;
+  v16u8 src = { 0 }, ref = { 0 }, tmp0, tmp1;
   v8i16 diff0, diff1;
   v4i32 out0, out1;
 
@@ -828,7 +831,7 @@ static int QuantizeBlock(int16_t in[16], int16_t out[16],
   tmp1 = (tmp3 > maxlevel);
   tmp2 = (v8i16)__msa_bmnz_v((v16u8)tmp2, (v16u8)maxlevel, (v16u8)tmp0);
   tmp3 = (v8i16)__msa_bmnz_v((v16u8)tmp3, (v16u8)maxlevel, (v16u8)tmp1);
-  SUB2(0, tmp2, 0, tmp3, tmp0, tmp1);
+  SUB2(zero, tmp2, zero, tmp3, tmp0, tmp1);
   tmp2 = (v8i16)__msa_bmnz_v((v16u8)tmp2, (v16u8)tmp0, (v16u8)sign0);
   tmp3 = (v8i16)__msa_bmnz_v((v16u8)tmp3, (v16u8)tmp1, (v16u8)sign1);
   LD_SW4(&mtx->zthresh_[0], 4, t0, t1, t2, t3);   // zthresh
diff --git a/src/dsp/lossless_msa.c b/src/dsp/lossless_msa.c
index f6dd5649..2529c7e3 100644
--- a/src/dsp/lossless_msa.c
+++ b/src/dsp/lossless_msa.c
@@ -43,7 +43,7 @@
 
 #define CONVERT8_BGRA_XXX(psrc, pdst, m0, m1) do {         \
   uint64_t pix_d;                                          \
-  v16u8 src0, src1, src2, dst0, dst1;                      \
+  v16u8 src0, src1, src2 = { 0 }, dst0, dst1;              \
   LD_UB2(psrc, 16, src0, src1);                            \
   VSHF_B2_UB(src0, src1, src1, src2, m0, m1, dst0, dst1);  \
   ST_UB(dst0, pdst);                                       \
diff --git a/src/dsp/msa_macro.h b/src/dsp/msa_macro.h
index d0e5f45e..dfacda6c 100644
--- a/src/dsp/msa_macro.h
+++ b/src/dsp/msa_macro.h
@@ -22,6 +22,7 @@
 #endif
 
 #ifdef CLANG_BUILD
+  #define ALPHAVAL  (-1)
   #define ADDVI_H(a, b)  __msa_addvi_h((v8i16)a, b)
   #define ADDVI_W(a, b)  __msa_addvi_w((v4i32)a, b)
   #define SRAI_B(a, b)  __msa_srai_b((v16i8)a, b)
@@ -32,6 +33,7 @@
   #define ANDI_B(a, b)  __msa_andi_b((v16u8)a, b)
   #define ORI_B(a, b)   __msa_ori_b((v16u8)a, b)
 #else
+  #define ALPHAVAL  (0xff)
   #define ADDVI_H(a, b)  (a + b)
   #define ADDVI_W(a, b)  (a + b)
   #define SRAI_B(a, b)  (a >> b)
diff --git a/src/dsp/upsampling_msa.c b/src/dsp/upsampling_msa.c
index f24926fa..561e4525 100644
--- a/src/dsp/upsampling_msa.c
+++ b/src/dsp/upsampling_msa.c
@@ -374,7 +374,7 @@ static void YuvToBgrLine(const uint8_t* y, const uint8_t* u,
 static void YuvToRgbaLine(const uint8_t* y, const uint8_t* u,
                           const uint8_t* v, uint8_t* dst, int length) {
   v16u8 R, G, B;
-  const v16u8 A = (v16u8)__msa_ldi_b(0xff);
+  const v16u8 A = (v16u8)__msa_ldi_b(ALPHAVAL);
   while (length >= 16) {
     CALC_RGB16(y, u, v, R, G, B);
     STORE16_4(R, G, B, A, dst);
@@ -402,7 +402,7 @@ static void YuvToRgbaLine(const uint8_t* y, const uint8_t* u,
 static void YuvToBgraLine(const uint8_t* y, const uint8_t* u,
                           const uint8_t* v, uint8_t* dst, int length) {
   v16u8 R, G, B;
-  const v16u8 A = (v16u8)__msa_ldi_b(0xff);
+  const v16u8 A = (v16u8)__msa_ldi_b(ALPHAVAL);
   while (length >= 16) {
     CALC_RGB16(y, u, v, R, G, B);
     STORE16_4(B, G, R, A, dst);
@@ -430,7 +430,7 @@ static void YuvToBgraLine(const uint8_t* y, const uint8_t* u,
 static void YuvToArgbLine(const uint8_t* y, const uint8_t* u,
                           const uint8_t* v, uint8_t* dst, int length) {
   v16u8 R, G, B;
-  const v16u8 A = (v16u8)__msa_ldi_b(0xff);
+  const v16u8 A = (v16u8)__msa_ldi_b(ALPHAVAL);
   while (length >= 16) {
     CALC_RGB16(y, u, v, R, G, B);
     STORE16_4(A, R, G, B, dst);