24-Bit Multiply Arithmetic

Multiply two 24-bit integer values held in 32-bit registers, returning the low or high part of the product.

Vendor-Neutral Definition

d = (a[23:0] * b[23:0]), truncated to the requested low or high 32-bit part.
⚠️ Cross-vendor mappings describe semantic relationships and are not guaranteed one-to-one compiler translations.
equivalent with restrictions Both compute an exact 24x24-bit integer product in a single instruction.
Property NVIDIA PTX AMDGPU
Instruction mul24 v_mul_i32_i24, v_mul_u32_u24
ISA Layer Virtual Native
Data Types - i32, u32
Version / Target Introduced PTX ISA 1.0 gfx1100, gfx1100

Important Differences

  • Selecting the signed vs. unsigned AMDGPU instruction must match PTX's signedness modifier on mul24; PTX's .hi form (returning the upper bits of the product) has no direct AMDGPU counterpart in this dataset since a 24x24-bit product already fits entirely in 48 bits without needing a separate high-part instruction.

Source Evidence

Verification method: documentation