[Bug] Fixed VPTERNLOG[D|Q] RW info when the predicate doesn't influence DST

src/asmjit/x86/x86instapi.cpp

@@ -827,7 +827,7 @@ Error InstInternal::queryRWInfo(Arch arch, const BaseInst& inst, const Operand_*
   constexpr OpRWFlags RegPhys = OpRWFlags::kRegPhysId;
   constexpr OpRWFlags MibRead = OpRWFlags::kMemBaseRead | OpRWFlags::kMemIndexRead;
 
-  if (instRwInfo.category == InstDB::RWInfo::kCategoryGeneric) {
+  if (instRwInfo.category <= uint32_t(InstDB::RWInfo::kCategoryGenericEx)) {
     uint32_t i;
     uint32_t rmOpsMask = 0;
     uint32_t rmMaxSize = 0;
@@ -948,6 +948,25 @@ Error InstInternal::queryRWInfo(Arch arch, const BaseInst& inst, const Operand_*
       } while (it.hasNext());
     }
 
+    // Special cases per instruction.
+    if (instRwInfo.category == InstDB::RWInfo::kCategoryGenericEx) {
+      switch (inst.id()) {
+        case Inst::kIdVpternlogd:
+        case Inst::kIdVpternlogq: {
+          if (opCount == 4 && operands[3].isImm()) {
+            uint32_t predicate = operands[3].as<Imm>().valueAs<uint8_t>();
+            if ((predicate >> 4) == (predicate & 0xF)) {
+              out->_operands[0].clearOpFlags(OpRWFlags::kRead);
+            }
+          }
+          break;
+        }
+
+        default:
+          break;
+      }
+    }
+
     return rwHandleAVX512(inst, commonInfo, out);
   }
 

src/asmjit/x86/x86instdb.cpp

@@ -5434,14 +5434,14 @@ const uint8_t InstDB::rwInfoIndexB[Inst::_kIdCount] = {
   84, 84, 3, 3, 164, 164, 164, 164, 3, 0, 0, 0, 0, 164, 164, 164, 164, 164, 164,
   3, 3, 120, 120, 120, 3, 164, 164, 3, 3, 120, 120, 120, 3, 3, 103, 84, 84, 84,
   3, 3, 3, 165, 166, 165, 3, 3, 3, 167, 165, 168, 3, 3, 3, 167, 165, 166, 165,
-  3, 3, 3, 167, 3, 3, 3, 3, 3, 3, 3, 3, 120, 120, 0, 103, 103, 103, 103, 103, 103,
+  3, 3, 3, 167, 3, 3, 3, 3, 3, 3, 3, 3, 169, 169, 0, 103, 103, 103, 103, 103, 103,
   103, 103, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 139, 141, 0, 0, 139, 141,
   0, 0, 139, 141, 0, 0, 140, 141, 84, 84, 84, 139, 140, 141, 84, 84, 84, 139, 140,
   141, 84, 84, 139, 141, 0, 0, 139, 141, 0, 0, 139, 141, 0, 0, 140, 141, 3, 3,
   3, 99, 100, 101, 0, 0, 10, 10, 10, 10, 10, 10, 10, 10, 0, 0, 3, 3, 3, 3, 3,
   3, 0, 0, 0, 139, 140, 141, 92, 3, 3, 3, 99, 100, 101, 0, 0, 0, 0, 0, 3, 3, 3,
-  3, 3, 3, 0, 0, 0, 0, 56, 56, 169, 0, 0, 0, 0, 0, 0, 0, 0, 0, 80, 0, 0, 0, 0, 0,
+  3, 3, 3, 0, 0, 0, 0, 56, 56, 170, 0, 0, 0, 0, 0, 0, 0, 0, 0, 80, 0, 0, 0, 0, 0,
-  170, 170, 170, 170, 171, 171, 171, 171, 171, 171, 171, 171, 169, 0, 0
+  171, 171, 171, 171, 172, 172, 172, 172, 172, 172, 172, 172, 170, 0, 0
 };
 
 const InstDB::RWInfo InstDB::rwInfoA[] = {
@@ -5705,7 +5705,7 @@ const InstDB::RWInfo InstDB::rwInfoB[] = {
   { InstDB::RWInfo::kCategoryGeneric   , 52, { 10, 80, 0 , 0 , 0 , 0  } }, // #117 [ref=2x]
   { InstDB::RWInfo::kCategoryGeneric   , 52, { 10, 3 , 0 , 0 , 0 , 0  } }, // #118 [ref=4x]
   { InstDB::RWInfo::kCategoryGeneric   , 53, { 79, 43, 0 , 0 , 0 , 0  } }, // #119 [ref=4x]
-  { InstDB::RWInfo::kCategoryGeneric   , 6 , { 2 , 3 , 3 , 0 , 0 , 0  } }, // #120 [ref=82x]
+  { InstDB::RWInfo::kCategoryGeneric   , 6 , { 2 , 3 , 3 , 0 , 0 , 0  } }, // #120 [ref=80x]
   { InstDB::RWInfo::kCategoryGeneric   , 42, { 4 , 5 , 5 , 0 , 0 , 0  } }, // #121 [ref=4x]
   { InstDB::RWInfo::kCategoryGeneric   , 40, { 4 , 61, 7 , 0 , 0 , 0  } }, // #122 [ref=1x]
   { InstDB::RWInfo::kCategoryGeneric   , 42, { 4 , 81, 9 , 0 , 0 , 0  } }, // #123 [ref=1x]
@@ -5754,9 +5754,10 @@ const InstDB::RWInfo InstDB::rwInfoB[] = {
   { InstDB::RWInfo::kCategoryGeneric   , 68, { 11, 3 , 0 , 0 , 0 , 0  } }, // #166 [ref=2x]
   { InstDB::RWInfo::kCategoryGeneric   , 69, { 11, 3 , 5 , 0 , 0 , 0  } }, // #167 [ref=3x]
   { InstDB::RWInfo::kCategoryGeneric   , 22, { 11, 3 , 5 , 0 , 0 , 0  } }, // #168 [ref=1x]
-  { InstDB::RWInfo::kCategoryGeneric   , 0 , { 60, 17, 29, 0 , 0 , 0  } }, // #169 [ref=2x]
+  { InstDB::RWInfo::kCategoryGenericEx , 6 , { 2 , 3 , 3 , 0 , 0 , 0  } }, // #169 [ref=2x]
-  { InstDB::RWInfo::kCategoryGeneric   , 8 , { 3 , 60, 17, 0 , 0 , 0  } }, // #170 [ref=4x]
+  { InstDB::RWInfo::kCategoryGeneric   , 0 , { 60, 17, 29, 0 , 0 , 0  } }, // #170 [ref=2x]
-  { InstDB::RWInfo::kCategoryGeneric   , 8 , { 11, 60, 17, 0 , 0 , 0  } }  // #171 [ref=8x]
+  { InstDB::RWInfo::kCategoryGeneric   , 8 , { 3 , 60, 17, 0 , 0 , 0  } }, // #171 [ref=4x]
+  { InstDB::RWInfo::kCategoryGeneric   , 8 , { 11, 60, 17, 0 , 0 , 0  } }  // #172 [ref=8x]
 };
 
 const InstDB::RWInfoOp InstDB::rwInfoOp[] = {

src/asmjit/x86/x86instdb_p.h

@@ -213,7 +213,8 @@ struct InstNameIndex {
 
 struct RWInfo {
   enum Category : uint8_t {
-    kCategoryGeneric,
+    kCategoryGeneric = 0,
+    kCategoryGenericEx,
     kCategoryMov,
     kCategoryMovabs,
     kCategoryImul,

tools/tablegen-x86.js

@@ -2236,8 +2236,18 @@ class InstRWInfoTable extends core.Task {
           }
         }
       }
+
+      const name = dbInsts.length ? dbInsts[0].name : "";
+
+      switch (name) {
+        case "vpternlogd":
+        case "vpternlogq":
+          return { category: "GenericEx", rwOps };
+
+        default:
           return { category: "Generic", rwOps };
       }
+    }
 
     function queryRwByData(dbInsts, rwOpsArray) {
       for (var i = 0; i < dbInsts.length; i++) {