SAM source code in Mac IDE

Does anyone know where the library source code is on a Mac install of the IDE for the ATSAM3X8E? I see that it SHOULD be in hardware/arduino/sam but only avr is present there.
I need to modify the DAC output functions.
I am able to build a project and run on the ATSAM3X8E no problem.

Thanks.

It is not supposed to be in hardware/arduino/sam, not in recent versions of the IDE. The avr stuff is there for reasons (though note that if you've upgraded the AVR board package using board manager, it's not even looking at /hardware/arduino/avr anymore!)

It's buried in the arduino15 folder - everything installed through board manager goes there. /Users/(username)/Library/Arduino15

You ROCK! Thanks!