Fixed some rounding issues with x87 interpretor (thx @pale)

ptitSeb · Sep 19, 2020 · b08960d · b08960d
1 parent 2c6e916
commit b08960d
Show file tree

Hide file tree

Showing 4 changed files with 8 additions and 65 deletions.
diff --git a/src/emu/rund9.h b/src/emu/rund9.h
@@ -132,7 +132,7 @@
                 emu->sw.f.F87_C3 = (ll&2)?1:0;
                 emu->sw.f.F87_C0 = (ll&4)?1:0;
             } else {
-                ll = (int64_t)(floor((ST0.d/ST1.d))/exp2(tmp32s - 32));
+                ll = (int64_t)(trunc((ST0.d/ST1.d))/exp2(tmp32s - 32));
                 ST0.d = ST0.d - ST1.d*ll*exp2(tmp32s - 32);
                 emu->sw.f.F87_C2 = 1;
             }

diff --git a/src/emu/rundb.h b/src/emu/rundb.h
@@ -113,21 +113,7 @@
                 if(isgreater(ST0.d, (double)(int32_t)0x7fffffff) || isless(ST0.d, -(double)(int32_t)0x7fffffff))
                     ED->sdword[0] = 0x80000000;
                 else {
-                    volatile int32_t tmp;    // tmp to avoid BUS ERROR
-                    switch(emu->round) {
-                        case ROUND_Nearest:
-                            ED->sdword[0] = floor(ST0.d+0.5);
-                            break;
-                        case ROUND_Down:
-                            ED->sdword[0] = floor(ST0.d);
-                            break;
-                        case ROUND_Up:
-                            ED->sdword[0] = ceil(ST0.d);
-                            break;
-                        case ROUND_Chop:
-                            ED->sdword[0] = ST0.d;
-                            break;
-                    }
+                    volatile int32_t tmp = fpu_round(emu, ST0.d);    // tmp to avoid BUS ERROR
                     ED->sdword[0] = tmp;
                 }
                 break;
@@ -136,21 +122,7 @@
                 if(isgreater(ST0.d, (double)(int32_t)0x7fffffff) || isless(ST0.d, -(double)(int32_t)0x7fffffff))
                     ED->sdword[0] = 0x80000000;
                 else {
-                    volatile int32_t tmp;    // tmp to avoid BUS ERROR
-                    switch(emu->round) {
-                        case ROUND_Nearest:
-                            tmp = floor(ST0.d+0.5);
-                            break;
-                        case ROUND_Down:
-                            tmp = floor(ST0.d);
-                            break;
-                        case ROUND_Up:
-                            tmp = ceil(ST0.d);
-                            break;
-                        case ROUND_Chop:
-                            tmp = ST0.d;
-                            break;
-                    }
+                    volatile int32_t tmp = fpu_round(emu, ST0.d);    // tmp to avoid BUS ERROR
                     ED->sdword[0] = tmp;
                 }
                 fpu_do_pop(emu);

diff --git a/src/emu/rundf.h b/src/emu/rundf.h
@@ -117,22 +117,8 @@
             GET_EW;
             if(isgreater(ST0.d, (double)(int32_t)0x7fff) || isless(ST0.d, -(double)(int32_t)0x7fff))
                 EW->sword[0] = 0x8000;
-            else {
-                switch(emu->round) {
-                    case ROUND_Nearest:
-                        EW->sword[0] = floor(ST0.d+0.5);
-                        break;
-                    case ROUND_Down:
-                        EW->sword[0] = floor(ST0.d);
-                        break;
-                    case ROUND_Up:
-                        EW->sword[0] = ceil(ST0.d);
-                        break;
-                    case ROUND_Chop:
-                        EW->sword[0] = ST0.d;
-                        break;
-                }
-            }
+            else
+                EW->sword[0] = fpu_round(emu, ST0.d);
             fpu_do_pop(emu);
             break;
         case 4: /* FBLD ST0, tbytes */
@@ -161,22 +147,7 @@
                 if(isgreater(ST0.d, (double)(int64_t)0x7fffffffffffffffLL) || isless(ST0.d, -(double)(int64_t)0x7fffffffffffffffLL))
                     *(int64_t*)ED = 0x8000000000000000LL;
                 else {
-                    int64_t i64;
-                    switch(emu->round) {
-                        case ROUND_Nearest:
-                            i64 = floor(ST0.d+0.5);
-                            break;
-                        case ROUND_Down:
-                            i64 = floor(ST0.d);
-                            break;
-                        case ROUND_Up:
-                            i64 = ceil(ST0.d);
-                            break;
-                        case ROUND_Chop:
-                        default:
-                            i64 = ST0.d;
-                            break;
-                    }
+                    int64_t i64 = fpu_round(emu, ST0.d);
                     *(int64_t*)ED = i64;
                 }
             }

diff --git a/src/emu/x87emu_private.h b/src/emu/x87emu_private.h
@@ -121,14 +121,14 @@ static inline double fpu_round(x86emu_t* emu, double d) {
         return d;
     switch(emu->round) {
         case ROUND_Nearest:
-            return floor(d+0.5);
+            return nearbyint(d);
         case ROUND_Down:
             return floor(d);
         case ROUND_Up:
             return ceil(d);
         case ROUND_Chop:
         default:
-            return round(d);
+            return trunc(d);
     }
 }