As far as I know, there is no instruction in SSE/AVX for loading an immediate. One workaround is loading a value to a normal register and movd, but compilers seem to think this is more costly than loading from memory even for a single scalar value.
This makes memory access necessary every time doing an operation with common constants such as 1, 0x80000000, 0x7fffffff, 0x3f800000, 0x3f000000, etc. Well, having these values encoded in the machine code will occupy 4 bytes each, but so does a 32-bit absolute or rip-relative address, and I believe an immediate load is cheaper than any sort of memory load.
I always thought something like movss xmm, imm32 or broadcastss xmm, imm32 would be nice to have, but there must be a reason for not making such instructions. Why was it designed this way?