This is a z80n-targeted repackaged snapshot of a Win64 build of SDCC - free open source, retargettable, optimizing ISO C compiler ( https://sdcc.sourceforge.net/ )
"Free open source, retargettable, optimizing ISO C compiler suite that targets a growing list of processors including the Intel MCS-51 based (8031, 8032, 8051, 8052, etc.), Maxim (formerly Dallas) DS80C390 variants, Freescale (formerly Motorola) HC08 based (hc08, s08), Zilog Z80 based MCUs (Z80, Z80N, Z180, SM83 (e.g. Game Boy), Rabbit 2000, Rabbit 2000A/3000, Rabbit 3000A, TLCS-90, R800), STMicroelectronics STM8, Padauk PDK14 and PDK15 and MOS 6502."
This repack is suitable only for the compilation for z80n target.
The exact build number can be seen by typing
sdcc --version
It also includes the sources from the 'device' directory from the SDCC's sources snapshot with the same build number and a Win64 build of ihx2bin by Jari Komppa (github.com/jarikomppa)