Arm64 vector ABI (#23675)

* Support for Arm64 Vector ABI

Extend HFA support to support vectors as well as floating point types.
This requires that the JIT recognize vector types even during crossgen,
so that the ABI is supported consistently.

Also, fix and re-enable the disabled Arm64 Simd tests.

Fix #16022

1 files changed, 8 insertions, 6 deletions

diff --git a/src/vm/argdestination.h b/src/vm/argdestination.h
index 386ba57c82..8ddd7b2104 100644
--- a/src/vm/argdestination.h
+++ b/src/vm/argdestination.h
@@ -60,22 +60,24 @@ public:
     //  fieldBytes - size of the structure
     void CopyHFAStructToRegister(void *src, int fieldBytes)
     {
-        // We are either copying either a float or double HFA and need to
+        // We are copying a float, double or vector HFA/HVA and need to
         // enregister each field.
 
         int floatRegCount = m_argLocDescForStructInRegs->m_cFloatReg;
-        bool typeFloat = m_argLocDescForStructInRegs->m_isSinglePrecision;
+        int hfaFieldSize = m_argLocDescForStructInRegs->m_hfaFieldSize;
         UINT64* dest = (UINT64*) this->GetDestinationAddress();
 
         for (int i = 0; i < floatRegCount; ++i) 
         {
             // Copy 4 or 8 bytes from src.
-            UINT64 val = typeFloat ? *((UINT32*)src + i) : *((UINT64*)src + i);
+            UINT64 val = (hfaFieldSize == 4) ? *((UINT32*)src) : *((UINT64*)src);
             // Always store 8 bytes
             *(dest++) = val;
-            // For now, always zero the next 8 bytes.
-            // (When HVAs are supported we will get the next 8 bytes from src.)
-            *(dest++) = 0;
+            // Either zero the next 8 bytes or get the next 8 bytes from src for 16-byte vector.
+            *(dest++) = (hfaFieldSize == 16) ? *((UINT64*)src + 1) : 0;
+
+            // Increment src by the appropriate amount.
+            src = (void*)((char*)src + hfaFieldSize);
         }
     }