Do these floating-point instructions use vxrm?
No. Ordinary RVV floating-point operations and FP conversions use floating-point frm or an instruction-specified fixed rounding mode; vxrm is for fixed-point rounding instructions.
VFDIV.VF
RISC-V VFDIV.VF Instruction Details
Instruction ManualR-typeDivide each float element of vs2 by f[rs1]: vd[i]=vs2[i]/f[rs1].
Instruction Syntax
vfdiv.vf vd, vs2, rs1, vm
Operand Breakdown
Destination rd: register receiving the operation result.
Source rs1: register holding the first operand.
Source rs2: register holding the second operand.
VZvfhVector OperationsFloating-Point
Related Search Terms
Instruction Behavior
VFDIV.VF performs floating-point division. The operation follows RVV floating-point rules, including NaN, rounding, and exception-flag behavior; estimate instructions provide an approximation with the precision defined by the spec. Vector FP32/FP64 operation requires the corresponding scalar F/D support; FP16 is controlled by the relevant vector half-precision extensions; do not assume the base V extension includes half-precision arithmetic.
Quick Understanding & Search Notes
VFDIV.VF is an RVV floating-point datapath instruction; reason about its result through FP semantics rather than integer bit patterns.
Exception flags and rounding behavior come from the floating-point environment.
The operation applies only to active elements within vl; inactive and tail elements follow the current vma/vta policy.
Except for dedicated mask forms, vm=0 uses v0 as the execution mask and vm=1 is unmasked.
Floating-point operations follow the vector FP rules: normal FP operations use frm rounding and set FP exception flags; fixed-point vxrm does not control them.
Common Usage Scenarios
Scientific Computing
Understand this scenario with real code like «vsetvli t0, a0, e32, m1, ta, ma vfdiv.vf v1, v2, ft0».
Normalization
Understand this scenario with real code like «vsetvli t0, a0, e32, m1, ta, ma vfdiv.vf v1, v2, ft0».
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
Do not summarize FP divide-by-zero as always producing infinity; 0/0, NaN operands, and signs follow IEEE/RISC-V FP rules.
FP exception flags follow floating-point rules; this is not integer division with an all-ones quotient.
Vector FP32/FP64 operation requires the corresponding scalar F/D support; FP16 is controlled by the relevant vector half-precision extensions, and the base V extension does not automatically include half-precision arithmetic.