They have a reason for doing things that way, which they state in the specification (in the PDF at https://www.cs.tufts.edu/~nr/c--/extern/man2.pdf https://www.

They have a reason for doing things that way, which they state in the specification (in the PDF at https://www.cs.tufts.edu/~nr/c--/extern/man2.pdf https://www.cs.tufts.edu/~nr/c--/extern/man2.pdf it's in figure 2 on page 10). I'm not knowledgeable enough in compilers and computer architecture to decide if it's a good reason. As far as I understand it, their reasoning is that implementations can easily enough figure out how the data is used to decide in which registers to put the data; distinguishing between integers and floats in the type system would be too restrictive, since they want to support architectures with more types of registers than the classic two.