Float16(Float(_builtinFloatLiteral: value))

float80->32->16.sil

sil_stage canonical

import Builtin
import Swift
import SwiftShims

func x()

// main
sil @main : $@convention(c) (Int32, UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>) -> Int32 {
bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>):
  %2 = integer_literal $Builtin.Int32, 0          // user: %3
  %3 = struct $Int32 (%2 : $Builtin.Int32)        // user: %4
  return %3 : $Int32                              // id: %4
} // end sil function 'main'

// x()
sil hidden @$s4main1xyyF : $@convention(thin) () -> () {
bb0:
  %0 = alloc_stack $Float16, var, name "x"        // users: %3, %4
  %1 = float_literal $Builtin.FPIEEE16, 0x3C00 // 1 // user: %2
  %2 = struct $Float16 (%1 : $Builtin.FPIEEE16)   // user: %3
  store %2 to %0 : $*Float16                      // id: %3
  dealloc_stack %0 : $*Float16                    // id: %4
  %5 = tuple ()                                   // user: %6
  return %5 : $()                                 // id: %6
} // end sil function '$s4main1xyyF'

// Float16.init(_builtinFloatLiteral:)
sil public_external [transparent] [serialized] @$ss7Float16V20_builtinFloatLiteralABBf80__tcfC : $@convention(method) (Builtin.FPIEEE80, @thin Float16.Type) -> Float16 {
// %0                                             // user: %2
bb0(%0 : $Builtin.FPIEEE80, %1 : $@thin Float16.Type):
  %2 = builtin "fptrunc_FPIEEE80_FPIEEE32"(%0 : $Builtin.FPIEEE80) : $Builtin.FPIEEE32 // user: %3
  %3 = builtin "fptrunc_FPIEEE32_FPIEEE16"(%2 : $Builtin.FPIEEE32) : $Builtin.FPIEEE16 // user: %4
  %4 = struct $Float16 (%3 : $Builtin.FPIEEE16)   // user: %5
  return %4 : $Float16                            // id: %5
} // end sil function '$ss7Float16V20_builtinFloatLiteralABBf80__tcfC'