ARm64/Sve: Fix the SVE_ComputeAddress* (#104039)

* Fix the SVE_ComputeAddress*

* review comments

* fix the typo

Author: kunalspathak

src/coreclr/jit/hwintrinsic.h

@@ -555,8 +555,10 @@ struct HWIntrinsicInfo
         return static_cast<CORINFO_InstructionSet>(result);
     }
 
-#ifdef TARGET_XARCH
+#if defined(TARGET_XARCH)
     static int lookupIval(Compiler* comp, NamedIntrinsic id, var_types simdBaseType);
+#elif defined(TARGET_ARM64)
+    static int lookupIval(NamedIntrinsic id);
 #endif
 
     static bool tryLookupSimdSize(NamedIntrinsic id, unsigned* pSimdSize)

src/coreclr/jit/hwintrinsicarm64.cpp

@@ -152,6 +152,31 @@ CORINFO_InstructionSet HWIntrinsicInfo::lookupIsa(const char* className, const c
     return InstructionSet_ILLEGAL;
 }
 
+//------------------------------------------------------------------------
+// lookupIval: Gets a the implicit immediate value for the given intrinsic
+//
+// Arguments:
+//    id           - The intrinsic for which to get the ival
+//
+// Return Value:
+//    The immediate value for the given intrinsic or -1 if none exists
+int HWIntrinsicInfo::lookupIval(NamedIntrinsic id)
+{
+    switch (id)
+    {
+        case NI_Sve_Compute16BitAddresses:
+            return 1;
+        case NI_Sve_Compute32BitAddresses:
+            return 2;
+        case NI_Sve_Compute64BitAddresses:
+            return 3;
+        case NI_Sve_Compute8BitAddresses:
+            return 0;
+        default:
+            unreached();
+    }
+    return -1;
+}
 //------------------------------------------------------------------------
 // isFullyImplementedIsa: Gets a value that indicates whether the InstructionSet is fully implemented
 //

src/coreclr/jit/hwintrinsiccodegenarm64.cpp

@@ -2118,12 +2118,8 @@ void CodeGen::genHWIntrinsic(GenTreeHWIntrinsic* node)
             case NI_Sve_Compute32BitAddresses:
             case NI_Sve_Compute64BitAddresses:
             {
-                static_assert_no_msg(AreContiguous(NI_Sve_Compute16BitAddresses, NI_Sve_Compute32BitAddresses,
-                                                   NI_Sve_Compute64BitAddresses, NI_Sve_Compute8BitAddresses));
-
                 GetEmitter()->emitInsSve_R_R_R_I(ins, EA_SCALABLE, targetReg, op1Reg, op2Reg,
-                                                 (intrin.id - NI_Sve_Compute16BitAddresses), opt,
-                                                 INS_SCALABLE_OPTS_LSL_N);
+                                                 HWIntrinsicInfo::lookupIval(intrin.id), opt, INS_SCALABLE_OPTS_LSL_N);
                 break;
             }