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PTX

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Revision as of 07:42, 18 July 2010 by Dank (talk | contribs)

The ISA to which CUDA's nvcc compiles source code. This is JIT'd into architecture-specific machine language by the hardware driver after the CUDA runtime is used to load a PTX module. It can then be scheduled for execution on CUDA devices. From Version 2.1 of the PTX ISA Reference:

PTX defines a virtual machine and ISA for general purpose parallel thread execution. PTX programs are translated at install time to the target hardware instruction set. The PTX-to-GPU translator and driver enable NVIDIA GPUs to be used as programmable parallel computers.

Versions

PTX Version CUDA Toolkit Version Changes
2.1 3.1
  • Stack-based API, indirect branches and function pointers for sm_2x targets
  • .branchtargets, .calltargets, and .callprototype directives
  • 32 driver-specific execution environment registers %envreg0..%envreg31
  • New instruction rcp.approx.ftz.f64 for fast approximate reciprocal
2.0 3.0

Tools

  • Marcin Wilhelm Kościelnicki's nv50dis, a disassembler