anaemic and out-of-date compared to ARM and x86. Approximately
100 additional Scalar Instructions are up for proposal**
+# Other Scalable Vector ISAs
+
+* Original Cray ISA
+ <http://www.bitsavers.org/pdf/cray/CRAY_Y-MP/HR-04001-0C_Cray_Y-MP_Computer_Systems_Functional_Description_Jun90.pdf>
+* NEC SX Aurora (still in production, inspired by Cray)
+ <https://www.hpc.nec/documents/guide/pdfs/Aurora_ISA_guide.pdf>
+* RISC-V RVV (inspired by Cray)
+ <https://github.com/riscv/riscv-v-spec>
+* MRISC32 ISA Manual (under active development)
+ <https://github.com/mrisc32/mrisc32/tree/master/isa-manual>
+* Mitch Alsup's MyISA 66000 Vector Processor ISA Manual is available from
+ Mitch on request.
+
+A comprehensive list of 3D GPU, Packed SIMD, Predicated-SIMD and true Scalable
+Vector ISAs may be found at the [[sv/vector_isa_comparison]] page.
+Note: AVX-512 and SVE2 are *not strict Vector ISAs*, they are Predicated-SIMD.
in AVX-512.
* ARM NEON - accurately described as a Packed SIMD ISA in
all literature.
-* ARM SVE / SVE2 - accurately described as a Scalable Vector
+* ARM SVE / SVE2 - partially accurately described as a Scalable Vector
ISA, but the "Scaling" is, rather unfortunately, a parameter
that is chosen by the *Hardware Architect*, rather than
- the programmer. This has resulted in programmers writing
- multiple variants of hand-coded assembler in order
+ the programmer. The actual "Scalar" part as far as the programmer
+ is concerned is supposed to be the Predicate Masks. However in
+ practice, ARM NEON programmers have found it too hard to adapt and
+ have instead attempted to fit the NEON SIMD paradigm on top of SVE.
+ This has resulted in programmers writing
+ **multiple variants** of near-identical hand-coded assembler in order
to target different machines with different hardware widths,
going directly against the advice given on ARM's developer
documentation.