target-mips: fix EXTPDP and setting up pos field in the DSPControl reg

This change makes sure that modifications of pos field in the DSPControl
register do not trash other bits in the register. This bug can be triggered
with the additional test case in mips32-dsp/extpdp.c in this commit.

In addition to this, this change corrects incorrect calculation of the mask
for EXTPDP.

Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
index a55f866581d25d88949d6c69adc4bda632af0c87..655dc8a9447307780319e925048cefd8212789a7 100644 (file)
--- a/target-mips/dsp_helper.c
+++ b/target-mips/dsp_helper.c
@@ -19,6 +19,7 @@
 
 #include "cpu.h"
 #include "helper.h"
+#include "qemu/bitops.h"
 
 /* As the byte ordering doesn't matter, i.e. all columns are treated
    identically, these unions can be used directly.  */
@@ -90,10 +91,10 @@ static inline void set_DSPControl_pos(uint32_t pos, CPUMIPSState *env)
     dspc = env->active_tc.DSPControl;
 #ifndef TARGET_MIPS64
     dspc = dspc & 0xFFFFFFC0;
-    dspc |= pos;
+    dspc |= (pos & 0x3F);
 #else
     dspc = dspc & 0xFFFFFF80;
-    dspc |= pos;
+    dspc |= (pos & 0x7F);
 #endif
     env->active_tc.DSPControl = dspc;
 }
@@ -3439,10 +3440,9 @@ target_ulong helper_extpdp(target_ulong ac, target_ulong size,
     if (sub >= -1) {
         acc  = ((uint64_t)env->active_tc.HI[ac] << 32) |
                ((uint64_t)env->active_tc.LO[ac] & MIPSDSP_LLO);
-        temp = (acc >> (start_pos - size)) &
-               (((uint32_t)0x01 << (size + 1)) - 1);
+        temp = extract64(acc, start_pos - size, size + 1);
 
-        set_DSPControl_pos(start_pos - (size + 1), env);
+        set_DSPControl_pos(sub, env);
         set_DSPControl_efi(0, env);
     } else {
         set_DSPControl_efi(1, env);

diff --git a/tests/tcg/mips/mips32-dsp/extpdp.c b/tests/tcg/mips/mips32-dsp/extpdp.c
index 15ba0828fb6fe5a5a48c9c90015be70a14d7321b..79ee16e8b87c662a75703152211a68c96820047b 100644 (file)
--- a/tests/tcg/mips/mips32-dsp/extpdp.c
+++ b/tests/tcg/mips/mips32-dsp/extpdp.c
@@ -42,5 +42,23 @@ int main()
     efi = (dsp >> 14) & 0x01;
     assert(efi == 1);
 
+
+    ach = 0;
+    acl = 0;
+    dsp = 0;
+    result = 0;
+
+    __asm
+        ("wrdsp %1\n\t"
+         "mthi %2, $ac1\n\t"
+         "mtlo %3, $ac1\n\t"
+         "extpdp %0, $ac1, 0x00\n\t"
+         "rddsp %1\n\t"
+         : "=r"(rt), "+r"(dsp)
+         : "r"(ach), "r"(acl)
+        );
+    assert(dsp == 0x3F);
+    assert(result == rt);
+
     return 0;
 }