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.VV
RISC-V VFDIV.VV Instruction Details
Instruction ManualR-typeDivide each float element of vs2 by vs1: vd[i]=vs2[i]/vs1[i].
Instruction Syntax
vfdiv.vv vd, vs2, vs1, 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.VV 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.VV 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.vv v1, v2, v3».
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.