Flag vector counts

src/jit/compiler.h

@@ -4938,6 +4938,7 @@ class Compiler
 #define LPFLG_VAR_LIMIT 0x0100    // iterator is compared with a local var (var # found in lpVarLimit)
 #define LPFLG_CONST_LIMIT 0x0200  // iterator is compared with a constant (found in lpConstLimit)
 #define LPFLG_ARRLEN_LIMIT 0x0400 // iterator is compared with a.len or a[i].len (found in lpArrLenLimit)
+#define LPFLG_SIMD_LIMIT 0x0080   // iterator is compared with Vector<T>.Count (found in lpConstLimit)
 
 #define LPFLG_HAS_PREHEAD 0x0800 // lpHead is known to be a preHead for this loop
 #define LPFLG_REMOVED 0x1000     // has been removed from the loop table (unrolled or optimized away)

src/jit/gentree.cpp

@@ -10716,6 +10716,13 @@ void Compiler::gtDispConst(GenTree* tree)
                     printf(" field offset");
                 }
 
+#ifdef FEATURE_SIMD
+                if ((tree->gtFlags & GTF_ICON_SIMD_COUNT) != 0)
+                {
+                    printf(" Vector<T>.Count");
+                }
+#endif
+
                 if ((tree->IsReuseRegVal()) != 0)
                 {
                     printf(" reuse reg val");

src/jit/gentree.h

@@ -933,6 +933,8 @@ struct GenTree
 
 #define GTF_ICON_FIELD_OFF 0x08000000 // GT_CNS_INT -- constant is a field offset
 
+#define GTF_ICON_SIMD_COUNT 0x04000000 // GT_CNS_INT -- constant is Vector<T>.Count
+
 #define GTF_BLK_VOLATILE 0x40000000  // GT_ASG, GT_STORE_BLK, GT_STORE_OBJ, GT_STORE_DYNBLK
                                      // -- is a volatile block operation
 #define GTF_BLK_UNALIGNED 0x02000000 // GT_ASG, GT_STORE_BLK, GT_STORE_OBJ, GT_STORE_DYNBLK

src/jit/optimizer.cpp

@@ -822,6 +822,10 @@ bool Compiler::optCheckIterInLoopTest(
     if (limitOp->gtOper == GT_CNS_INT)
     {
         optLoopTable[loopInd].lpFlags |= LPFLG_CONST_LIMIT;
+        if ((limitOp->gtFlags & GTF_ICON_SIMD_COUNT) != 0)
+        {
+            optLoopTable[loopInd].lpFlags |= LPFLG_SIMD_LIMIT;
+        }
     }
     else if (limitOp->gtOper == GT_LCL_VAR && !optIsVarAssigned(from, to, nullptr, limitOp->gtLclVarCommon.gtLclNum))
     {

src/jit/simd.cpp

@@ -1812,6 +1812,8 @@ GenTreePtr Compiler::impSIMDIntrinsic(OPCODE                opcode,
             int            length       = getSIMDVectorLength(clsHnd);
             GenTreeIntCon* intConstTree = new (this, GT_CNS_INT) GenTreeIntCon(TYP_INT, length);
             retVal                      = intConstTree;
+
+            intConstTree->gtFlags |= GTF_ICON_SIMD_COUNT;
         }
         break;