[LoongArch64] JIT/EE interface for getting ABI-info

docs/design/coreclr/botr/clr-abi.md

@@ -26,6 +26,8 @@ Arm corporation ABI documentation (for ARM32 and ARM64) is [here](https://develo
 
 The Linux System V x86_64 ABI is documented in [System V Application Binary Interface / AMD64 Architecture Processor Supplement](https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-1.0.pdf), with document source material [here](https://gitlab.com/x86-psABIs/x86-64-ABI).
 
+The LoongArch64 ABI documentation is [here](https://github.com/loongson/LoongArch-Documentation/blob/main/docs/LoongArch-ELF-ABI-EN.adoc)
+
 # General Unwind/Frame Layout
 
 For all non-x86 platforms, all methods must have unwind information so the garbage collector (GC) can unwind them (unlike native code in which a leaf method may be omitted).

src/coreclr/inc/corinfo.h

@@ -316,6 +316,45 @@ struct SYSTEMV_AMD64_CORINFO_STRUCT_REG_PASSING_DESCRIPTOR
     }
 };
 
+// StructFloadFieldInfoFlags: used on LoongArch64 architecture by `getLoongArch64PassStructInRegisterFlags` API
+// to convey struct argument passing information.
+//
+// `STRUCT_NO_FLOAT_FIELD` means structs are not passed using the float register(s).
+//
+// Otherwise, and only for structs with no more than two fields and a total struct size no larger
+// than two pointers:
+//
+// The lowest four bits denote the floating-point info:
+//   bit 0: `1` means there is only one float or double field within the struct.
+//   bit 1: `1` means only the first field is floating-point type.
+//   bit 2: `1` means only the second field is floating-point type.
+//   bit 3: `1` means the two fields are both floating-point type.
+// The bits[5:4] denoting whether the field size is 8-bytes:
+//   bit 4: `1` means the first field's size is 8.
+//   bit 5: `1` means the second field's size is 8.
+//
+// Note that bit 0 and 3 cannot both be set.
+enum StructFloatFieldInfoFlags
+{
+    STRUCT_NO_FLOAT_FIELD         = 0x0,
+    STRUCT_FLOAT_FIELD_ONLY_ONE   = 0x1,
+    STRUCT_FLOAT_FIELD_ONLY_TWO   = 0x8,
+    STRUCT_FLOAT_FIELD_FIRST      = 0x2,
+    STRUCT_FLOAT_FIELD_SECOND     = 0x4,
+    STRUCT_FIRST_FIELD_SIZE_IS8   = 0x10,
+    STRUCT_SECOND_FIELD_SIZE_IS8  = 0x20,
+
+    STRUCT_FIRST_FIELD_DOUBLE     = (STRUCT_FLOAT_FIELD_FIRST | STRUCT_FIRST_FIELD_SIZE_IS8),
+    STRUCT_SECOND_FIELD_DOUBLE    = (STRUCT_FLOAT_FIELD_SECOND | STRUCT_SECOND_FIELD_SIZE_IS8),
+    STRUCT_FIELD_TWO_DOUBLES      = (STRUCT_FIRST_FIELD_SIZE_IS8 | STRUCT_SECOND_FIELD_SIZE_IS8 | STRUCT_FLOAT_FIELD_ONLY_TWO),
+
+    STRUCT_MERGE_FIRST_SECOND     = (STRUCT_FLOAT_FIELD_FIRST | STRUCT_FLOAT_FIELD_ONLY_TWO),
+    STRUCT_MERGE_FIRST_SECOND_8   = (STRUCT_FLOAT_FIELD_FIRST | STRUCT_FLOAT_FIELD_ONLY_TWO | STRUCT_SECOND_FIELD_SIZE_IS8),
+
+    STRUCT_HAS_FLOAT_FIELDS_MASK  = (STRUCT_FLOAT_FIELD_FIRST | STRUCT_FLOAT_FIELD_SECOND | STRUCT_FLOAT_FIELD_ONLY_TWO | STRUCT_FLOAT_FIELD_ONLY_ONE),
+    STRUCT_HAS_8BYTES_FIELDS_MASK = (STRUCT_FIRST_FIELD_SIZE_IS8 | STRUCT_SECOND_FIELD_SIZE_IS8),
+};
+
 #include "corinfoinstructionset.h"
 
 // CorInfoHelpFunc defines the set of helpers (accessed via the ICorDynamicInfo::getHelperFtn())
@@ -2843,6 +2882,7 @@ class ICorStaticInfo
         /* OUT */   SYSTEMV_AMD64_CORINFO_STRUCT_REG_PASSING_DESCRIPTOR* structPassInRegDescPtr
         ) = 0;
 
+    virtual uint32_t getLoongArch64PassStructInRegisterFlags(CORINFO_CLASS_HANDLE cls) = 0;
 };
 
 /*****************************************************************************

src/coreclr/inc/icorjitinfoimpl_generated.h

@@ -480,6 +480,9 @@ bool getSystemVAmd64PassStructInRegisterDescriptor(
           CORINFO_CLASS_HANDLE structHnd,
           SYSTEMV_AMD64_CORINFO_STRUCT_REG_PASSING_DESCRIPTOR* structPassInRegDescPtr) override;
 
+uint32_t getLoongArch64PassStructInRegisterFlags(
+          CORINFO_CLASS_HANDLE structHnd) override;
+
 uint32_t getThreadTLSIndex(
           void** ppIndirection) override;
 

src/coreclr/inc/jiteeversionguid.h

@@ -43,12 +43,12 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* e6a73797-0cbe-4cf8-b4ad-724a25466211 */
-    0xe6a73797,
-    0x0cbe,
-    0x4cf8,
-    {0xb4, 0xad, 0x72, 0x4a, 0x25, 0x46, 0x62, 0x11}
-};
+constexpr GUID JITEEVersionIdentifier = { /* 80a6aaf7-7fb3-44b2-8fe5-95fd47308798 */
+    0x80a6aaf7,
+    0x7fb3,
+    0x44b2,
+    {0x8f, 0xe5, 0x95, 0xfd, 0x47, 0x30, 0x87, 0x98}
+  };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////
 //

src/coreclr/jit/ICorJitInfo_API_names.h

@@ -122,6 +122,7 @@ DEF_CLR_API(getMethodNameFromMetadata)
 DEF_CLR_API(getMethodHash)
 DEF_CLR_API(findNameOfToken)
 DEF_CLR_API(getSystemVAmd64PassStructInRegisterDescriptor)
+DEF_CLR_API(getLoongArch64PassStructInRegisterFlags)
 DEF_CLR_API(getThreadTLSIndex)
 DEF_CLR_API(getInlinedCallFrameVptr)
 DEF_CLR_API(getAddrOfCaptureThreadGlobal)

src/coreclr/jit/ICorJitInfo_API_wrapper.hpp

@@ -1154,6 +1154,15 @@ bool WrapICorJitInfo::getSystemVAmd64PassStructInRegisterDescriptor(
     return temp;
 }
 
+uint32_t WrapICorJitInfo::getLoongArch64PassStructInRegisterFlags(
+          CORINFO_CLASS_HANDLE structHnd)
+{
+    API_ENTER(getLoongArch64PassStructInRegisterFlags);
+    uint32_t temp = wrapHnd->getLoongArch64PassStructInRegisterFlags(structHnd);
+    API_LEAVE(getLoongArch64PassStructInRegisterFlags);
+    return temp;
+}
+
 uint32_t WrapICorJitInfo::getThreadTLSIndex(
           void** ppIndirection)
 {