it to hold the address of an sret return value, for x86-64 ABI purposes.
Also, fix the test that was originally intended to test this to actually
test it, using FileCheck.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83853 91177308-0d34-0410-b5e6-96231b3b80d8
argument. The x86-64 ABI requires the incoming value of %rdi to
be copied to %rax on exit from a function that is returning a
large C struct.
Also, add a README-X86-64 entry detailing the missed optimization
opportunity and proposing an alternative approach.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50075 91177308-0d34-0410-b5e6-96231b3b80d8
