I'm sorry I'm new to this.
Did the first compiler writer, for example the C compiler, knew all of intel x86 machine instructions. I'm asking because, some compilers compile source code to the processor's machine instructions right? So the compiler has to know all the machine instructions for that processor right?
But intel machine instructions are secret right? So did intel give out an assembler for their CPUs or something? I'm so confused, I have been searching the internet for two days. Please help.