Fix divw[.] and divwo[.] emulation.

Also adds a couple of tests for undocumented
CPU behaviour. Remove superfluous "sidiv".

cpu/ppc/ppcemu.h

@@ -137,7 +137,6 @@ extern uint64_t timebase_counter; //used for storing time base value
 
 //Additional steps to prevent overflow?
 extern int32_t add_result;
-extern int32_t sidiv_result;
 extern int32_t simult_result;
 extern uint32_t uiadd_result;
 extern uint32_t uidiv_result;

cpu/ppc/ppcopcodes.cpp

@@ -41,7 +41,6 @@ uint32_t ppc_result_b = 0;
 uint32_t ppc_result_c = 0;
 uint32_t ppc_result_d = 0;
 
-int32_t sidiv_result;
 uint32_t uidiv_result;
 uint64_t uiproduct;
 int64_t siproduct;
@@ -923,115 +922,65 @@ void ppc_mulli() {
 void ppc_divw() {
     ppc_grab_regsdab();
 
-    //handle division by zero cases
-    switch (ppc_result_b) {
-    case 0:
-        ppc_result_d = 0;
-        ppc_store_result_regd();
-        return;
-    case 0xFFFFFFFF:
-        if (ppc_result_a == 0x80000000) {
-            ppc_result_d = 0xFFFFFFFF;
-            ppc_store_result_regd();
-            ppc_state.ppc_cr &= 0x1FFFFFFF;
-            return;
-        }
-    default:
-        sidiv_result = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
-        ppc_result_d = sidiv_result;
-        ppc_store_result_regd();
+    if (!ppc_result_b) { /* handle the "anything / 0" case */
+        ppc_result_d = (ppc_result_a & 0x80000000) ? -1 : 0; /* UNDOCUMENTED! */
+    } else if (ppc_result_a == 0x80000000UL && ppc_result_b == 0xFFFFFFFFUL) {
+        ppc_result_d = 0xFFFFFFFF;
+    } else { /* normal signed devision */
+        ppc_result_d = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
     }
+
+    ppc_store_result_regd();
 }
 
 void ppc_divwdot() {
     ppc_grab_regsdab();
 
-    //handle division by zero cases
-    switch (ppc_result_b) {
-    case 0:
-        ppc_result_d = 0;
-        ppc_store_result_regd();
-        if ((ppc_result_a == 0) | (ppc_result_a == 0x7FFFFFFF))
-            ppc_state.ppc_cr |= 0x20000000;
-        return;
-    case 0xFFFFFFFF:
-        if (ppc_result_a == 0x80000000) {
-            ppc_result_d = 0xFFFFFFFF;
-            ppc_store_result_regd();
-            ppc_state.ppc_cr |= 0x80000000;
-            return;
-        }
-    default:
-        sidiv_result = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
-        ppc_result_d = sidiv_result;
-        ppc_changecrf0(ppc_result_d);
-        ppc_store_result_regd();
+    if (!ppc_result_b) { /* handle the "anything / 0" case */
+        ppc_result_d = (ppc_result_a & 0x80000000) ? -1 : 0; /* UNDOCUMENTED! */
+    } else if (ppc_result_a == 0x80000000UL && ppc_result_b == 0xFFFFFFFFUL) {
+        ppc_result_d = 0xFFFFFFFF;
+    } else { /* normal signed devision */
+        ppc_result_d = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
     }
+
+    ppc_changecrf0(ppc_result_d);
+    ppc_store_result_regd();
 }
 
 void ppc_divwo() {
     ppc_grab_regsdab();
 
-    //handle division by zero cases
-    switch (ppc_result_b) {
-    case 0:
-        ppc_result_d = 0;
-        ppc_store_result_regd();
-        if ((ppc_result_a == 0) | (ppc_result_a == 0x7FFFFFFF))
-            ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
-        return;
-    case 0xFFFFFFFF:
-        if (ppc_result_a == 0x80000000UL) {
-            ppc_result_d = 0xFFFFFFFF;
-            ppc_store_result_regd();
-            ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
-            return;
-        }
-        else if (ppc_result_a == 0x7FFFFFFFUL) {
-            ppc_result_d = 0x80000001;
-            ppc_store_result_regd();
-            return;
-        }
-    default:
-        sidiv_result = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
-        ppc_result_d = sidiv_result;
-        ppc_setsoov_divwo(ppc_result_a, ppc_result_d);
-        ppc_store_result_regd();
+    if (!ppc_result_b) { /* handle the "anything / 0" case */
+        ppc_result_d = (ppc_result_a & 0x80000000) ? -1 : 0; /* UNDOCUMENTED! */
+        ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
+    } else if (ppc_result_a == 0x80000000UL && ppc_result_b == 0xFFFFFFFFUL) {
+        ppc_result_d = 0xFFFFFFFF;
+        ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
+    } else { /* normal signed devision */
+        ppc_result_d = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
+        ppc_state.ppc_spr[SPR::XER] &= 0xBFFFFFFFUL;
     }
+
+    ppc_store_result_regd();
 }
 
 void ppc_divwodot() {
     ppc_grab_regsdab();
 
-    //handle division by zero cases
-    switch (ppc_result_b) {
-    case 0:
-        ppc_result_d = 0;
-        ppc_store_result_regd();
+    if (!ppc_result_b) { /* handle the "anything / 0" case */
+        ppc_result_d = (ppc_result_a & 0x80000000) ? -1 : 0; /* UNDOCUMENTED! */
         ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
-        ppc_state.ppc_cr |= 0x30000000;
-        return;
-    case 0xFFFFFFFF:
-        if (ppc_result_a == 0x80000000UL) {
-            ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
-            ppc_state.ppc_cr |= 0x90000000;
-            ppc_result_d = 0xFFFFFFFF;
-            ppc_store_result_regd();
-            return;
-        }
-        else if (ppc_result_a == 0x7FFFFFFFUL) {
-            ppc_result_d = 0x80000001;
-            ppc_state.ppc_cr |= 0x80000000;
-            ppc_store_result_regd();
-            return;
-        }
-    default:
-        sidiv_result = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
-        ppc_result_d = (uint32_t)sidiv_result;
-        ppc_setsoov_divwo(ppc_result_a, ppc_result_d);
-        ppc_changecrf0(ppc_result_d);
-        ppc_store_result_regd();
+    } else if (ppc_result_a == 0x80000000UL && ppc_result_b == 0xFFFFFFFFUL) {
+        ppc_result_d = 0xFFFFFFFF;
+        ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
+    } else { /* normal signed devision */
+        ppc_result_d = (int32_t)ppc_result_a / (int32_t)ppc_result_b;
+        ppc_state.ppc_spr[SPR::XER] &= 0xBFFFFFFFUL;
     }
+
+    ppc_changecrf0(ppc_result_d);
+    ppc_store_result_regd();
 }
 
 void ppc_divwu() {

cpu/ppc/test/ppcinttest.txt

@@ -286,7 +286,11 @@ cntlzw.  :: rD 0x00000001 | rA 0x40000000 | XER: 0x00000000 | CR: 0x40000000
 cntlzw.  :: rD 0x00000000 | rA 0x80000000 | XER: 0x00000000 | CR: 0x20000000
 divw     :: rD 0x00000000 | rA 0x00000000 | rB 0x00000000 | XER: 0x00000000 | CR: 0x00000000
 divw     :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x00000000 | XER: 0x00000000 | CR: 0x00000000
+divw     :: rD 0xFFFFFFFF | rA 0x8FFFFFFF | rB 0x00000000 | XER: 0x00000000 | CR: 0x00000000
+divw     :: rD 0x00000000 | rA 0x00000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
 divw     :: rD 0x80000001 | rA 0x7FFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
+divw     :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR: 0x00000000
+divw     :: rD 0xFFFFFFFF | rA 0x7FFFFFFF | rB 0x80000001 | XER: 0x00000000 | CR: 0x00000000
 divw     :: rD 0xFFFFFFFF | rA 0x80000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
 divw     :: rD 0x00000000 | rA 0x00000000 | rB 0x00000001 | XER: 0x00000000 | CR: 0x00000000
 divw     :: rD 0x00000001 | rA 0x00000001 | rB 0x00000001 | XER: 0x00000000 | CR: 0x00000000
@@ -297,7 +301,11 @@ divw     :: rD 0x00000000 | rA 0xFFFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR
 divw     :: rD 0x00000001 | rA 0xFFFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
 divw.    :: rD 0x00000000 | rA 0x00000000 | rB 0x00000000 | XER: 0x00000000 | CR: 0x20000000
 divw.    :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x00000000 | XER: 0x00000000 | CR: 0x20000000
+divw.    :: rD 0xFFFFFFFF | rA 0x8FFFFFFF | rB 0x00000000 | XER: 0x00000000 | CR: 0x80000000
+divw.    :: rD 0x00000000 | rA 0x00000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x20000000
 divw.    :: rD 0x80000001 | rA 0x7FFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x80000000
+divw.    :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR: 0x20000000
+divw.    :: rD 0xFFFFFFFF | rA 0x7FFFFFFF | rB 0x80000001 | XER: 0x00000000 | CR: 0x80000000
 divw.    :: rD 0xFFFFFFFF | rA 0x80000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x80000000
 divw.    :: rD 0x00000000 | rA 0x00000000 | rB 0x00000001 | XER: 0x00000000 | CR: 0x20000000
 divw.    :: rD 0x00000001 | rA 0x00000001 | rB 0x00000001 | XER: 0x00000000 | CR: 0x40000000
@@ -308,7 +316,11 @@ divw.    :: rD 0x00000000 | rA 0xFFFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR
 divw.    :: rD 0x00000001 | rA 0xFFFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x40000000
 divwo    :: rD 0x00000000 | rA 0x00000000 | rB 0x00000000 | XER: 0xC0000000 | CR: 0x00000000
 divwo    :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x00000000 | XER: 0xC0000000 | CR: 0x00000000
+divwo    :: rD 0xFFFFFFFF | rA 0x8FFFFFFF | rB 0x00000000 | XER: 0xC0000000 | CR: 0x00000000
+divwo    :: rD 0x00000000 | rA 0x00000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
 divwo    :: rD 0x80000001 | rA 0x7FFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
+divwo    :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR: 0x00000000
+divwo    :: rD 0xFFFFFFFF | rA 0x7FFFFFFF | rB 0x80000001 | XER: 0x00000000 | CR: 0x00000000
 divwo    :: rD 0xFFFFFFFF | rA 0x80000000 | rB 0xFFFFFFFF | XER: 0xC0000000 | CR: 0x00000000
 divwo    :: rD 0x00000000 | rA 0x00000000 | rB 0x00000001 | XER: 0x00000000 | CR: 0x00000000
 divwo    :: rD 0x00000001 | rA 0x00000001 | rB 0x00000001 | XER: 0x00000000 | CR: 0x00000000
@@ -319,7 +331,11 @@ divwo    :: rD 0x00000000 | rA 0xFFFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR
 divwo    :: rD 0x00000001 | rA 0xFFFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x00000000
 divwo.   :: rD 0x00000000 | rA 0x00000000 | rB 0x00000000 | XER: 0xC0000000 | CR: 0x30000000
 divwo.   :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x00000000 | XER: 0xC0000000 | CR: 0x30000000
+divwo.   :: rD 0xFFFFFFFF | rA 0x8FFFFFFF | rB 0x00000000 | XER: 0xC0000000 | CR: 0x90000000
+divwo.   :: rD 0x00000000 | rA 0x00000000 | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x20000000
 divwo.   :: rD 0x80000001 | rA 0x7FFFFFFF | rB 0xFFFFFFFF | XER: 0x00000000 | CR: 0x80000000
+divwo.   :: rD 0x00000000 | rA 0x7FFFFFFF | rB 0x80000000 | XER: 0x00000000 | CR: 0x20000000
+divwo.   :: rD 0xFFFFFFFF | rA 0x7FFFFFFF | rB 0x80000001 | XER: 0x00000000 | CR: 0x80000000
 divwo.   :: rD 0xFFFFFFFF | rA 0x80000000 | rB 0xFFFFFFFF | XER: 0xC0000000 | CR: 0x90000000
 divwo.   :: rD 0x00000000 | rA 0x00000000 | rB 0x00000001 | XER: 0x00000000 | CR: 0x20000000
 divwo.   :: rD 0x00000001 | rA 0x00000001 | rB 0x00000001 | XER: 0x00000000 | CR: 0x40000000

cpu/ppc/test/ppcinttests.csv

@@ -286,7 +286,11 @@ CNTLZW.,0x7C630035,rD=0x00000001,rA=0x40000000,XER=0x00000000,CR=0x40000000
 CNTLZW.,0x7C630035,rD=0x00000000,rA=0x80000000,XER=0x00000000,CR=0x20000000
 DIVW,0x7C6323D6,rD=0x00000000,rA=0x00000000,rB=0x00000000,XER=0x00000000,CR=0x00000000
 DIVW,0x7C6323D6,rD=0x00000000,rA=0x7FFFFFFF,rB=0x00000000,XER=0x00000000,CR=0x00000000
+DIVW,0x7C6323D6,rD=0xFFFFFFFF,rA=0x8FFFFFFF,rB=0x00000000,XER=0x00000000,CR=0x00000000
+DIVW,0x7C6323D6,rD=0x00000000,rA=0x00000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
 DIVW,0x7C6323D6,rD=0x80000001,rA=0x7FFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
+DIVW,0x7C6323D6,rD=0x00000000,rA=0x7FFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x00000000
+DIVW,0x7C6323D6,rD=0xFFFFFFFF,rA=0x7FFFFFFF,rB=0x80000001,XER=0x00000000,CR=0x00000000
 DIVW,0x7C6323D6,rD=0xFFFFFFFF,rA=0x80000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
 DIVW,0x7C6323D6,rD=0x00000000,rA=0x00000000,rB=0x00000001,XER=0x00000000,CR=0x00000000
 DIVW,0x7C6323D6,rD=0x00000001,rA=0x00000001,rB=0x00000001,XER=0x00000000,CR=0x00000000
@@ -297,7 +301,11 @@ DIVW,0x7C6323D6,rD=0x00000000,rA=0xFFFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x00
 DIVW,0x7C6323D6,rD=0x00000001,rA=0xFFFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
 DIVW.,0x7C6323D7,rD=0x00000000,rA=0x00000000,rB=0x00000000,XER=0x00000000,CR=0x20000000
 DIVW.,0x7C6323D7,rD=0x00000000,rA=0x7FFFFFFF,rB=0x00000000,XER=0x00000000,CR=0x20000000
+DIVW.,0x7C6323D7,rD=0xFFFFFFFF,rA=0x8FFFFFFF,rB=0x00000000,XER=0x00000000,CR=0x80000000
+DIVW.,0x7C6323D7,rD=0x00000000,rA=0x00000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x20000000
 DIVW.,0x7C6323D7,rD=0x80000001,rA=0x7FFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x80000000
+DIVW.,0x7C6323D7,rD=0x00000000,rA=0x7FFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x20000000
+DIVW.,0x7C6323D7,rD=0xFFFFFFFF,rA=0x7FFFFFFF,rB=0x80000001,XER=0x00000000,CR=0x80000000
 DIVW.,0x7C6323D7,rD=0xFFFFFFFF,rA=0x80000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x80000000
 DIVW.,0x7C6323D7,rD=0x00000000,rA=0x00000000,rB=0x00000001,XER=0x00000000,CR=0x20000000
 DIVW.,0x7C6323D7,rD=0x00000001,rA=0x00000001,rB=0x00000001,XER=0x00000000,CR=0x40000000
@@ -308,7 +316,11 @@ DIVW.,0x7C6323D7,rD=0x00000000,rA=0xFFFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x2
 DIVW.,0x7C6323D7,rD=0x00000001,rA=0xFFFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x40000000
 DIVWO,0x7C6327D6,rD=0x00000000,rA=0x00000000,rB=0x00000000,XER=0xC0000000,CR=0x00000000
 DIVWO,0x7C6327D6,rD=0x00000000,rA=0x7FFFFFFF,rB=0x00000000,XER=0xC0000000,CR=0x00000000
+DIVWO,0x7C6327D6,rD=0xFFFFFFFF,rA=0x8FFFFFFF,rB=0x00000000,XER=0xC0000000,CR=0x00000000
+DIVWO,0x7C6327D6,rD=0x00000000,rA=0x00000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
 DIVWO,0x7C6327D6,rD=0x80000001,rA=0x7FFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
+DIVWO,0x7C6327D6,rD=0x00000000,rA=0x7FFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x00000000
+DIVWO,0x7C6327D6,rD=0xFFFFFFFF,rA=0x7FFFFFFF,rB=0x80000001,XER=0x00000000,CR=0x00000000
 DIVWO,0x7C6327D6,rD=0xFFFFFFFF,rA=0x80000000,rB=0xFFFFFFFF,XER=0xC0000000,CR=0x00000000
 DIVWO,0x7C6327D6,rD=0x00000000,rA=0x00000000,rB=0x00000001,XER=0x00000000,CR=0x00000000
 DIVWO,0x7C6327D6,rD=0x00000001,rA=0x00000001,rB=0x00000001,XER=0x00000000,CR=0x00000000
@@ -319,7 +331,11 @@ DIVWO,0x7C6327D6,rD=0x00000000,rA=0xFFFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x0
 DIVWO,0x7C6327D6,rD=0x00000001,rA=0xFFFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x00000000
 DIVWO.,0x7C6327D7,rD=0x00000000,rA=0x00000000,rB=0x00000000,XER=0xC0000000,CR=0x30000000
 DIVWO.,0x7C6327D7,rD=0x00000000,rA=0x7FFFFFFF,rB=0x00000000,XER=0xC0000000,CR=0x30000000
+DIVWO.,0x7C6327D7,rD=0xFFFFFFFF,rA=0x8FFFFFFF,rB=0x00000000,XER=0xC0000000,CR=0x90000000
+DIVWO.,0x7C6327D7,rD=0x00000000,rA=0x00000000,rB=0xFFFFFFFF,XER=0x00000000,CR=0x20000000
 DIVWO.,0x7C6327D7,rD=0x80000001,rA=0x7FFFFFFF,rB=0xFFFFFFFF,XER=0x00000000,CR=0x80000000
+DIVWO.,0x7C6327D7,rD=0x00000000,rA=0x7FFFFFFF,rB=0x80000000,XER=0x00000000,CR=0x20000000
+DIVWO.,0x7C6327D7,rD=0xFFFFFFFF,rA=0x7FFFFFFF,rB=0x80000001,XER=0x00000000,CR=0x80000000
 DIVWO.,0x7C6327D7,rD=0xFFFFFFFF,rA=0x80000000,rB=0xFFFFFFFF,XER=0xC0000000,CR=0x90000000
 DIVWO.,0x7C6327D7,rD=0x00000000,rA=0x00000000,rB=0x00000001,XER=0x00000000,CR=0x20000000
 DIVWO.,0x7C6327D7,rD=0x00000001,rA=0x00000001,rB=0x00000001,XER=0x00000000,CR=0x40000000