NASM 2.05 based x86 Instruction Reference[ch108]
A.5.88 FLD: Floating-Point Load FLD mem32 ; D9 /0 [8086,FPU] FLD mem64 ; DD /0 [8086,FPU] FLD mem80 ; DB /5 [8086,FPU] FLD fpureg ; D9 C0+r [8086,FPU] FLD loads a floating-point value out of the given register or memory location, and pushes it on the FPU register stack.