Does divide by zero trap?
No. The V extension defines the divide-by-zero result and the instruction itself does not raise a divide-by-zero exception.
VDIV.VX
RISC-V VDIV.VX Instruction Details
Instruction ManualR-typeDivide each signed vs2 element by x[rs1], quotient to vd; division by zero does not trap.
Instruction Syntax
vdiv.vx 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.
VVector OperationsInteger Arithmetic
Instruction Behavior
VDIV.VX performs RVV signed integer division and writes the quotient to vd. Division by zero does not trap and returns the specified quotient; signed overflow cases follow the specified result.
Quick Understanding & Search Notes
VDIV.VX is element-wise integer division. It follows the RISC-V integer-division style of not trapping on divide-by-zero, which makes it usable in vectorized quotient loops.
The quotient is written to vd; use VREM/VREMU for remainders.
Divide-by-zero does not raise a synchronous exception, so software must explicitly test divisors when it needs an error path.
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.
Common Usage Scenarios
Numerical Computing
Understand this scenario with real code like «vsetvli t0, a0, e32, m1, ta, ma vdiv.vx v1, v2, a1».
Scaling
Understand this scenario with real code like «vsetvli t0, a0, e32, m1, ta, ma vdiv.vx v1, v2, a1».
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
Divide-by-zero does not trap; software must explicitly test divisors when it needs an error path.