FADD.S
RISC-V FADD.S Instruction Details
Instruction ManualR-typePerforms single-precision floating-point addition: rd = rs1+rs2.
Instruction Syntax
fadd.s rd, rs1, rs2, rm
Operand Breakdown
rd: destination floating-point register receiving the formatted result.
rs1/rs2: source floating-point registers; arithmetic/rounding forms with rm use rm or dynamic frm for rounding mode.
FFloating-Point Arithmetic
Instruction Behavior
FADD.S adds single-precision values in rs1 and rs2; result to rd. R-type using OP-FP opcode. Rounding by rm (static or dynamic from frm). IEEE 754 subnormal arithmetic supported.
Common Usage Scenarios
Floating Point Basic
Understand this scenario with real code like «fadd.s f0, f1, f2 # f0 = f1+f2 (RNE)».
Pre-Use Checklist
Syntax Check
- Confirm the current instruction format is R-type.
- Confirm the operand order matches the example.
Semantic Check
- Ensure the destination register usage is compatible with the calling convention.
- Confirm this is not the lower-level form of a pseudo-instruction expansion.
Pitfalls / Common Confusions
floating-point addition is not associative