Merge pull request #14018 from sdmaclea/PR-ARM-Remove-extra-cast

[Arm/Arm64] LowerCast remove small int widen cast

src/jit/codegenarm.cpp

@@ -1555,7 +1555,7 @@ void CodeGen::genIntToFloatCast(GenTreePtr treeNode)
     assert(genIsValidIntReg(op1->gtRegNum)); // Must be a valid int reg.
 
     var_types dstType = treeNode->CastToType();
-    var_types srcType = op1->TypeGet();
+    var_types srcType = genActualType(op1->TypeGet());
     assert(!varTypeIsFloating(srcType) && varTypeIsFloating(dstType));
 
     // force the srcType to unsigned if GT_UNSIGNED flag is set
@@ -1565,9 +1565,6 @@ void CodeGen::genIntToFloatCast(GenTreePtr treeNode)
     }
 
     // We only expect a srcType whose size is EA_4BYTE.
-    // For conversions from small types (byte/sbyte/int16/uint16) to float/double,
-    // we expect the front-end or lowering phase to have generated two levels of cast.
-    //
     emitAttr srcSize = EA_ATTR(genTypeSize(srcType));
     noway_assert(srcSize == EA_4BYTE);
 

src/jit/codegenarm64.cpp

@@ -3232,7 +3232,7 @@ void CodeGen::genIntToFloatCast(GenTreePtr treeNode)
     assert(genIsValidIntReg(op1->gtRegNum)); // Must be a valid int reg.
 
     var_types dstType = treeNode->CastToType();
-    var_types srcType = op1->TypeGet();
+    var_types srcType = genActualType(op1->TypeGet());
     assert(!varTypeIsFloating(srcType) && varTypeIsFloating(dstType));
 
     // force the srcType to unsigned if GT_UNSIGNED flag is set
@@ -3242,9 +3242,6 @@ void CodeGen::genIntToFloatCast(GenTreePtr treeNode)
     }
 
     // We should never see a srcType whose size is neither EA_4BYTE or EA_8BYTE
-    // For conversions from small types (byte/sbyte/int16/uint16) to float/double,
-    // we expect the front-end or lowering phase to have generated two levels of cast.
-    //
     emitAttr srcSize = EA_ATTR(genTypeSize(srcType));
     noway_assert((srcSize == EA_4BYTE) || (srcSize == EA_8BYTE));
 

src/jit/lowerarmarch.cpp

@@ -393,13 +393,7 @@ void Lowering::LowerBlockStore(GenTreeBlk* blkNode)
 //    None.
 //
 // Notes:
-//    Casts from small int type to float/double are transformed as follows:
-//    GT_CAST(byte, float/double)     =   GT_CAST(GT_CAST(byte, int32), float/double)
-//    GT_CAST(sbyte, float/double)    =   GT_CAST(GT_CAST(sbyte, int32), float/double)
-//    GT_CAST(int16, float/double)    =   GT_CAST(GT_CAST(int16, int32), float/double)
-//    GT_CAST(uint16, float/double)   =   GT_CAST(GT_CAST(uint16, int32), float/double)
-//
-//    Similarly casts from float/double to a smaller int type are transformed as follows:
+//    Casts from float/double to a smaller int type are transformed as follows:
 //    GT_CAST(float/double, byte)     =   GT_CAST(GT_CAST(float/double, int32), byte)
 //    GT_CAST(float/double, sbyte)    =   GT_CAST(GT_CAST(float/double, int32), sbyte)
 //    GT_CAST(float/double, int16)    =   GT_CAST(GT_CAST(double/double, int32), int16)
@@ -419,23 +413,18 @@ void Lowering::LowerCast(GenTree* tree)
 
     GenTreePtr op1     = tree->gtOp.gtOp1;
     var_types  dstType = tree->CastToType();
-    var_types  srcType = op1->TypeGet();
+    var_types  srcType = genActualType(op1->TypeGet());
     var_types  tmpType = TYP_UNDEF;
 
     if (varTypeIsFloating(srcType))
     {
         noway_assert(!tree->gtOverflow());
     }
 
-    // Case of src is a small type and dst is a floating point type.
-    if (varTypeIsSmall(srcType) && varTypeIsFloating(dstType))
-    {
-        // These conversions can never be overflow detecting ones.
-        noway_assert(!tree->gtOverflow());
-        tmpType = TYP_INT;
-    }
+    assert(!varTypeIsSmall(srcType));
+
     // case of src is a floating point type and dst is a small type.
-    else if (varTypeIsFloating(srcType) && varTypeIsSmall(dstType))
+    if (varTypeIsFloating(srcType) && varTypeIsSmall(dstType))
     {
         NYI_ARM("Lowering for cast from float to small type"); // Not tested yet.
         tmpType = TYP_INT;

src/jit/lsraarm64.cpp

@@ -302,17 +302,7 @@ void LinearScan::TreeNodeInfoInit(GenTree* tree)
             {
                 castOpType = genUnsignedType(castOpType);
             }
-#ifdef DEBUG
-            if (!tree->gtOverflow() && (varTypeIsFloating(castToType) || varTypeIsFloating(castOpType)))
-            {
-                // If converting to float/double, the operand must be 4 or 8 byte in size.
-                if (varTypeIsFloating(castToType))
-                {
-                    unsigned opSize = genTypeSize(castOpType);
-                    assert(opSize == 4 || opSize == 8);
-                }
-            }
-#endif // DEBUG
+
             // Some overflow checks need a temp reg
 
             Lowering::CastInfo castInfo;