target-mips: Fix incorrect reads and writes to DSPControl register

Upper 4 bits of ccond (bits 31..28 ) of DSPControl register are not used in
the MIPS32 architecture. They are used in the MIPS64 architecture. For MIPS32
these bits must be written as zero, and return zero on read.

The change fixes writes (WRDSP) and reads (RDDSP) to the register. It also fixes
the tests that use these instructions, and makes them smaller and simpler.

Signed-off-by: Petar Jovanovic <petarj@mips.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

3 files changed, 32 insertions, 40 deletions

diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
index 14daf91950..acf7ceb1d1 100644
--- a/target-mips/dsp_helper.c
+++ b/target-mips/dsp_helper.c
@@ -3948,7 +3948,11 @@ void helper_wrdsp(target_ulong rs, target_ulong mask_num, CPUMIPSState *env)
     if (mask[4] == 1) {
         overwrite &= 0x00FFFFFF;
         newbits   &= 0x00FFFFFF;
+#if defined(TARGET_MIPS64)
         newbits   |= 0xFF000000 & rs;
+#else
+        newbits   |= 0x0F000000 & rs;
+#endif
     }
 
     if (mask[5] == 1) {
@@ -3999,7 +4003,11 @@ target_ulong helper_rddsp(target_ulong masknum, CPUMIPSState *env)
     }
 
     if (mask[4] == 1) {
+#if defined(TARGET_MIPS64)
         temp |= dsp & 0xFF000000;
+#else
+        temp |= dsp & 0x0F000000;
+#endif
     }
 
     if (mask[5] == 1) {
diff --git a/tests/tcg/mips/mips32-dsp/rddsp.c b/tests/tcg/mips/mips32-dsp/rddsp.c
index e8948ec1d9..2f30285033 100644
--- a/tests/tcg/mips/mips32-dsp/rddsp.c
+++ b/tests/tcg/mips/mips32-dsp/rddsp.c
@@ -6,14 +6,13 @@ int main()
     int dsp_i, dsp_o;
     int ccond_i, outflag_i, efi_i, c_i, scount_i, pos_i;
     int ccond_o, outflag_o, efi_o, c_o, scount_o, pos_o;
-    int ccond_r, outflag_r, efi_r, c_r, scount_r, pos_r;
 
-    ccond_i   = 0x000000BC;/* 4 */
-    outflag_i = 0x0000001B;/* 3 */
-    efi_i     = 0x00000001;/* 5 */
-    c_i       = 0x00000001;/* 2 */
-    scount_i  = 0x0000000F;/* 1 */
-    pos_i     = 0x0000000C;/* 0 */
+    ccond_i   = 0x0000000C;  /* 4 */
+    outflag_i = 0x0000001B;  /* 3 */
+    efi_i     = 0x00000001;  /* 5 */
+    c_i       = 0x00000001;  /* 2 */
+    scount_i  = 0x0000000F;  /* 1 */
+    pos_i     = 0x0000000C;  /* 0 */
 
     dsp_i = (ccond_i   << 24) | \
             (outflag_i << 16) | \
@@ -22,13 +21,6 @@ int main()
             (scount_i  <<  7) | \
             pos_i;
 
-    ccond_r   = ccond_i;
-    outflag_r = outflag_i;
-    efi_r     = efi_i;
-    c_r       = c_i;
-    scount_r  = scount_i;
-    pos_r     = pos_i;
-
     __asm
         ("wrdsp %1, 0x3F\n\t"
          "rddsp %0, 0x3F\n\t"
@@ -43,12 +35,12 @@ int main()
     scount_o  = (dsp_o >>  7) & 0x3F;
     pos_o     =  dsp_o & 0x1F;
 
-    assert(ccond_o   == ccond_r);
-    assert(outflag_o == outflag_r);
-    assert(efi_o     == efi_r);
-    assert(c_o       == c_r);
-    assert(scount_o  == scount_r);
-    assert(pos_o     == pos_r);
+    assert(ccond_o   == ccond_i);
+    assert(outflag_o == outflag_i);
+    assert(efi_o     == efi_i);
+    assert(c_o       == c_i);
+    assert(scount_o  == scount_i);
+    assert(pos_o     == pos_i);
 
     return 0;
 }
diff --git a/tests/tcg/mips/mips32-dsp/wrdsp.c b/tests/tcg/mips/mips32-dsp/wrdsp.c
index e8948ec1d9..dc54943a99 100644
--- a/tests/tcg/mips/mips32-dsp/wrdsp.c
+++ b/tests/tcg/mips/mips32-dsp/wrdsp.c
@@ -6,14 +6,13 @@ int main()
     int dsp_i, dsp_o;
     int ccond_i, outflag_i, efi_i, c_i, scount_i, pos_i;
     int ccond_o, outflag_o, efi_o, c_o, scount_o, pos_o;
-    int ccond_r, outflag_r, efi_r, c_r, scount_r, pos_r;
 
-    ccond_i   = 0x000000BC;/* 4 */
-    outflag_i = 0x0000001B;/* 3 */
-    efi_i     = 0x00000001;/* 5 */
-    c_i       = 0x00000001;/* 2 */
-    scount_i  = 0x0000000F;/* 1 */
-    pos_i     = 0x0000000C;/* 0 */
+    ccond_i   = 0x000000BC;  /* 4 */
+    outflag_i = 0x0000001B;  /* 3 */
+    efi_i     = 0x00000001;  /* 5 */
+    c_i       = 0x00000001;  /* 2 */
+    scount_i  = 0x0000000F;  /* 1 */
+    pos_i     = 0x0000000C;  /* 0 */
 
     dsp_i = (ccond_i   << 24) | \
             (outflag_i << 16) | \
@@ -22,13 +21,6 @@ int main()
             (scount_i  <<  7) | \
             pos_i;
 
-    ccond_r   = ccond_i;
-    outflag_r = outflag_i;
-    efi_r     = efi_i;
-    c_r       = c_i;
-    scount_r  = scount_i;
-    pos_r     = pos_i;
-
     __asm
         ("wrdsp %1, 0x3F\n\t"
          "rddsp %0, 0x3F\n\t"
@@ -43,12 +35,12 @@ int main()
     scount_o  = (dsp_o >>  7) & 0x3F;
     pos_o     =  dsp_o & 0x1F;
 
-    assert(ccond_o   == ccond_r);
-    assert(outflag_o == outflag_r);
-    assert(efi_o     == efi_r);
-    assert(c_o       == c_r);
-    assert(scount_o  == scount_r);
-    assert(pos_o     == pos_r);
+    assert(ccond_o   == (ccond_i & 0x0F));
+    assert(outflag_o == outflag_i);
+    assert(efi_o     == efi_i);
+    assert(c_o       == c_i);
+    assert(scount_o  == scount_i);
+    assert(pos_o     == pos_i);
 
     return 0;
 }