Add with Carry-Out Arithmetic

Add two operands and record the carry-out of the addition for use by a subsequent extended-precision add.

Vendor-Neutral Definition

d = a + b (mod 2^width); carry_out_flag = 1 if the true sum overflowed width bits, else 0.
⚠️ Cross-vendor mappings describe semantic relationships and are not guaranteed one-to-one compiler translations.
equivalent with restrictions Both add two operands and record whether the result overflowed, for use in a following extended-precision add.
Property NVIDIA PTX AMDGPU
Instruction add.cc v_add_co_u32, s_add_u32
ISA Layer Virtual Native
Data Types - u32
Version / Target Introduced PTX ISA 1.2 gfx1100, gfx942/gfx1100

Important Differences

  • PTX writes carry-out to a dedicated condition-code (CC) register read implicitly by the next .cc-suffixed instruction; AMDGPU's carry-out is read from VCC (vector form) or SCC (scalar form), general-purpose condition registers also affected by many other instructions - the two mechanisms are not drop-in equivalent register conventions.

Source Evidence

Verification method: documentation