Added new conversion instructions instead of changing the behaviour of the existing ones.

Author: GarveyJoe

sycl/doc/extensions/SPIRV/SPV_INTEL_usm_storage_classes.asciidoc

@@ -39,7 +39,9 @@ This extension requires SPIR-V 1.0.
 
 == Overview
 
-This extension introduces two new storage classes that are sub classes of the CrossWorkgroup storage class.  Using these more specific storage classes provides additional information that can enable optimization. 
+This extension introduces two new storage classes that are sub classes of the CrossWorkgroup storage class.  
+Using these more specific storage classes provides additional information that can enable optimization. 
+The extension also introduces two new conversion instructions to enable converting pointers from and to these storage classes.  
 
 == Extension Name
 To use this extension within a SPIR-V module, the following *OpExtension* must be present in the module:
@@ -61,9 +63,11 @@ USMStorageClassesINTEL
 [cols="70%,30%"]
 [grid="rows"]
 |====
+| OpPtrCastToCrossWorkgroupINTEL | 5934
 | USMStorageClassesINTEL  | 5935
 | DeviceOnlyINTEL | 5936
 | HostOnlyINTEL | 5937
+| OpCrossWorkgroupCastToPtrINTEL | 5938
 |====
 
 == Modifications to the SPIR-V Specification, Version 1.5 Revision 3
@@ -96,30 +100,38 @@ Modify Section 3.31, Capability, adding a row to the Capability table:
 
 === Instructions
 
-Modify Section 3.36.11, Conversion Instructions, replacing the descriptions of *OpPtrCastToGeneric* and *OpGenericCastToPtr* with the following.  Their required capabilities and operands remain unchanged.  
+Modify Section 3.36.11, Conversion Instructions, adding two new instructions as follows:
 
 |===
-*OpPtrCastToGeneric*
+3+^| *OpPtrCastToCrossWorkgroupINTEL*
 
-Converts a pointer's Storage Class to a more generic class.
+Converts a pointer's Storage Class from a more specific class to *CrossWorkgroup*.
 
-_Result Type_ must be an OpTypePointer.  Its Storage Class must be *Generic* or *CrossWorkgroup*.  
+_Result Type_ must be an OpTypePointer.  Its Storage Class must be *CrossWorkgroup*.  
 
-If _Result Type_'s Storage Class is *Generic*, _Pointer_ must point to the *Workgroup*, *CrossWorkgroup*, *Function*, *DeviceOnlyINTEL*, or *HostOnlyINTEL* Storage Class.  If _Result Type_'s Storage Class is *CrossWorkgroup*, _Pointer_ must point to the *DeviceOnlyINTEL* or *HostOnlyINTEL* Storage Class.  
+_Pointer_ must point to the *DeviceOnlyINTEL* or *HostOnlyINTEL* Storage Class.  
 
-_Result Type_ and _Pointer_ must point to the same type.
+_Result Type_ and _Pointer_ must point to the same type. 2+^| Capability: +
+*USMStorageClassesINTEL*
+| 4 | 5934 | <id> +
+Result Type | Result <id> | <id> +
+Pointer
 |===
 
 |===
-*OpGenericCastToPtr*
+3+^| *OpCrossWorkgroupCastToPtrINTEL*
 
-Convert a pointer's Storage Class to a more specific class.
+Convert a pointer's Storage Class from *CrossWorkgroup* to a more specific class.
 
-_Result Type_ must be an OpTypePointer.  If _Pointer_ points to the *Generic* Storage Class, _Result Type_'s Storage Class must be *Workgroup*, *CrossWorkgroup*, *Function*, *DeviceOnlyINTEL*, or *HostOnlyINTEL*. If _Pointer_ points to the *CrossWorkgroup* storage class, _Result Type_'s Storage Class must be *DeviceOnlyINTEL* or *HostOnlyINTEL*.
+_Result Type_ must be an OpTypePointer.  _Result Type_'s Storage Class must be *DeviceOnlyINTEL* or *HostOnlyINTEL*.
 
-_Pointer_ must point to the *Generic* or *CrossWorkgroup* Storage Class.
+_Pointer_ must point to the *CrossWorkgroup* Storage Class.
 
-_Result Type_ and _Pointer_ must point to the same type.  
+_Result Type_ and _Pointer_ must point to the same type.  2+^| Capability: +
+*USMStorageClassesINTEL*
+| 4 | 5938 | <id> +
+Result Type | Result <id> | <id> +
+Pointer
 |===
 
 === Validation Rules
@@ -144,4 +156,5 @@ None.
 |========================================
 |Rev|Date|Author|Changes
 |A|2020-06-08|Joe Garvey|*First public draft*
+|B|2020-06-18|Joe Garvey|*Added new conversion instructions*
 |========================================