Hi VYoung,
Many FPGA devices supporting phase-shifting clocks, such as Agilex 7, Stratix 10, Arria 10, Cyclone 10, MAX 10 and so on. The phase shift is basically implemented by PLL and most of Intel FPGAs contains PLL.
For example, you can find out in Intel® Arria® 10 Core Fabric and General Purpose I/Os Handbook Chapter 4.2. Intel® Arria® 10 PLLs to know how we can implement the phase shift in Arria 10 device.
"The VCO frequency of the PLL determines the precision of the phase shift. The minimum phase shift increment is 1/8 (for I/O PLL) or 1/4 (for fPLL) of the VCO period. For example, if an I/O PLL operates with a VCO frequency of 1000 MHz, phase shift steps of 125 ps are possible."
https://www.intel.com/content/www/us/en/docs/programmable/683461/current/plls.html
Not sure if this answers your question?
Thanks & Regards,
Xiaoyan