Xcode 3.1.4 Release was released on 9 Jul 2009 and requires macOS 10.5.7+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/xcode_3.1.4_developer_tools/xcode314_2809_developerdvd.dmg.
Release notes are located at https://download.developer.apple.com/Developer_Tools/xcode_3.1.4_developer_tools/about_xcode_tools_3.1.4.pdf.
The compilers it contains are:
- LLVM-GCC (Build 2064.3)
- GCC 4.0 (Build 5493)
- GCC 4.2 (Build 5577)