diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
index f975da0..805247d 100644
--- a/target-mips/dsp_helper.c
+++ b/target-mips/dsp_helper.c
@@ -682,49 +682,31 @@
 
 static inline uint8_t mipsdsp_lshift8(uint8_t a, uint8_t s, CPUMIPSState *env)
 {
-    uint8_t sign;
     uint8_t discard;
 
-    if (s == 0) {
-        return a;
-    } else {
-        sign = (a >> 7) & 0x01;
-        if (sign != 0) {
-            discard = (((0x01 << (8 - s)) - 1) << s) |
-                      ((a >> (6 - (s - 1))) & ((0x01 << s) - 1));
-        } else {
-            discard = a >> (6 - (s - 1));
-        }
+    if (s != 0) {
+        discard = a >> (8 - s);
 
         if (discard != 0x00) {
             set_DSPControl_overflow_flag(1, 22, env);
         }
-        return a << s;
     }
+    return a << s;
 }
 
 static inline uint16_t mipsdsp_lshift16(uint16_t a, uint8_t s,
                                         CPUMIPSState *env)
 {
-    uint8_t  sign;
     uint16_t discard;
 
-    if (s == 0) {
-        return a;
-    } else {
-        sign = (a >> 15) & 0x01;
-        if (sign != 0) {
-            discard = (((0x01 << (16 - s)) - 1) << s) |
-                      ((a >> (14 - (s - 1))) & ((0x01 << s) - 1));
-        } else {
-            discard = a >> (14 - (s - 1));
-        }
+    if (s != 0) {
+        discard = (int16_t)a >> (15 - s);
 
         if ((discard != 0x0000) && (discard != 0xFFFF)) {
             set_DSPControl_overflow_flag(1, 22, env);
         }
-        return a << s;
     }
+    return a << s;
 }
 
 
diff --git a/tests/tcg/mips/mips32-dsp/shll_ph.c b/tests/tcg/mips/mips32-dsp/shll_ph.c
index b8f1ff5..5fa58cc 100644
--- a/tests/tcg/mips/mips32-dsp/shll_ph.c
+++ b/tests/tcg/mips/mips32-dsp/shll_ph.c
@@ -11,7 +11,38 @@
     resultdsp = 1;
 
     __asm
-        ("shll.ph %0, %2, 0x0B\n\t"
+        ("wrdsp $0\n\t"
+         "shll.ph %0, %2, 0x0B\n\t"
+         "rddsp %1\n\t"
+         : "=r"(rd), "=r"(dsp)
+         : "r"(rt)
+        );
+    dsp = (dsp >> 22) & 0x01;
+    assert(dsp == resultdsp);
+    assert(rd  == result);
+
+    rt        = 0x7fff8000;
+    result    = 0xfffe0000;
+    resultdsp = 1;
+
+    __asm
+        ("wrdsp $0\n\t"
+         "shll.ph %0, %2, 0x01\n\t"
+         "rddsp %1\n\t"
+         : "=r"(rd), "=r"(dsp)
+         : "r"(rt)
+        );
+    dsp = (dsp >> 22) & 0x01;
+    assert(dsp == resultdsp);
+    assert(rd  == result);
+
+    rt        = 0x00000001;
+    result    = 0x00008000;
+    resultdsp = 1;
+
+    __asm
+        ("wrdsp $0\n\t"
+         "shll.ph %0, %2, 0x0F\n\t"
          "rddsp %1\n\t"
          : "=r"(rd), "=r"(dsp)
          : "r"(rt)
diff --git a/tests/tcg/mips/mips32-dsp/shll_qb.c b/tests/tcg/mips/mips32-dsp/shll_qb.c
index 8c1b91c..729716d 100644
--- a/tests/tcg/mips/mips32-dsp/shll_qb.c
+++ b/tests/tcg/mips/mips32-dsp/shll_qb.c
@@ -11,12 +11,14 @@
     resultdsp = 0x00;
 
     __asm
-        ("shll.qb %0, %2, 0x00\n\t"
+        ("wrdsp $0\n\t"
+         "shll.qb %0, %2, 0x00\n\t"
          "rddsp   %1\n\t"
          : "=r"(rd), "=r"(dsp)
          : "r"(rt)
         );
     dsp = (dsp >> 22) & 0x01;
+    assert(dsp == resultdsp);
     assert(rd == result);
 
     rt     = 0x87654321;
@@ -24,12 +26,29 @@
     resultdsp = 0x01;
 
     __asm
-        ("shll.qb %0, %2, 0x03\n\t"
+        ("wrdsp $0\n\t"
+         "shll.qb %0, %2, 0x03\n\t"
          "rddsp   %1\n\t"
          : "=r"(rd), "=r"(dsp)
          : "r"(rt)
         );
     dsp = (dsp >> 22) & 0x01;
+    assert(dsp == resultdsp);
+    assert(rd == result);
+
+    rt     = 0x00000001;
+    result = 0x00000080;
+    resultdsp = 0x00;
+
+    __asm
+        ("wrdsp $0\n\t"
+         "shll.qb %0, %2, 0x07\n\t"
+         "rddsp   %1\n\t"
+         : "=r"(rd), "=r"(dsp)
+         : "r"(rt)
+        );
+    dsp = (dsp >> 22) & 0x01;
+    assert(dsp == resultdsp);
     assert(rd == result);
 
     return 0;