[WebAssembly] Fix return type of __builtin_return_address under wasm64

llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp

enum RuntimeLibcallSignature {
   i64_i64_func_f64,
   i16_i16_func_i16_i16,
   i32_i32_func_i32_i32,
   i64_i64_func_i64_i64,
   i64_i64_func_i64_i64_i64_i64,
   i64_i64_func_i64_i64_i64_i64_iPTR,
   i64_i64_i64_i64_func_i64_i64_i64_i64,
   i64_i64_func_i64_i64_i32,
+  iPTR_func_i32,
   iPTR_func_iPTR_i32_iPTR,
   iPTR_func_iPTR_iPTR_iPTR,
   f32_func_f32_f32_f32,
   f64_func_f64_f64_f64,
   func_i64_i64_iPTR_iPTR,
   func_iPTR_f32,
   func_iPTR_f64,
   func_iPTR_i32,
RuntimeLibcallSignatureTable() : Table(RTLIB::UNKNOWN_LIBCALL, unsupported) {
     Table[RTLIB::MEMCPY] = iPTR_func_iPTR_iPTR_iPTR;
     Table[RTLIB::MEMSET] = iPTR_func_iPTR_i32_iPTR;
     Table[RTLIB::MEMMOVE] = iPTR_func_iPTR_iPTR_iPTR;
 
     // __stack_chk_fail
     Table[RTLIB::STACKPROTECTOR_CHECK_FAIL] = func;
 
     // Return address handling
-    Table[RTLIB::RETURN_ADDRESS] = i32_func_i32;
+    Table[RTLIB::RETURN_ADDRESS] = iPTR_func_i32;
 
     // Element-wise Atomic memory
     // TODO: Fix these when we implement atomic support
     Table[RTLIB::MEMCPY_ELEMENT_UNORDERED_ATOMIC_1] = unsupported;
     Table[RTLIB::MEMCPY_ELEMENT_UNORDERED_ATOMIC_2] = unsupported;
     Table[RTLIB::MEMCPY_ELEMENT_UNORDERED_ATOMIC_4] = unsupported;
     Table[RTLIB::MEMCPY_ELEMENT_UNORDERED_ATOMIC_8] = unsupported;
     Table[RTLIB::MEMCPY_ELEMENT_UNORDERED_ATOMIC_16] = unsupported;
#if 0 // TODO: Enable this when wasm gets multiple-return-value support.
     Rets.push_back(wasm::ValType::I64);
 #else
     Params.push_back(PtrTy);
 #endif
     Params.push_back(wasm::ValType::I64);
     Params.push_back(wasm::ValType::I64);
     Params.push_back(wasm::ValType::I32);
     break;
+  case iPTR_func_i32:
+    Rets.push_back(PtrTy);
+    Params.push_back(wasm::ValType::I32);
+    break;
   case iPTR_func_iPTR_i32_iPTR:
     Rets.push_back(PtrTy);
     Params.push_back(PtrTy);
     Params.push_back(wasm::ValType::I32);
     Params.push_back(PtrTy);
     break;
   case iPTR_func_iPTR_iPTR_iPTR:
     Rets.push_back(PtrTy);

llvm/test/CodeGen/WebAssembly/return-address-emscripten.ll

-; RUN: llc < %s -asm-verbose=false | FileCheck %s
-
-target triple = "wasm32-unknown-emscripten"
+; RUN: llc -mtriple=wasm32-unknown-emscripten < %s -asm-verbose=false | FileCheck -DPTR=32 %s
+; RUN: llc -mtriple=wasm64-unknown-emscripten < %s -asm-verbose=false | FileCheck -DPTR=64 %s
 
 ; This tests the implementation of __builtin_return_address on emscripten
 
 ; CHECK-LABEL: test_returnaddress:
-; CHECK-NEXT: .functype test_returnaddress () -> (i32){{$}}
+; CHECK-NEXT: .functype test_returnaddress () -> (i[[PTR]]){{$}}
 ; CHECK-NEXT: {{^}} i32.const 0{{$}}
 ; CHECK-NEXT: {{^}} call emscripten_return_address{{$}}
 ; CHECK-NEXT: {{^}} end_function{{$}}
 define i8* @test_returnaddress() {
   %r = call i8* @llvm.returnaddress(i32 0)
   ret i8* %r
 }
 
 ; LLVM represents __builtin_return_address as call to this function in IR.
 declare i8* @llvm.returnaddress(i32 immarg)