From 3cde36d4290510062bd9e5f6ccbfd814be75e254 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Thu, 28 Jul 2022 04:30:40 +0100 Subject: [PATCH] add sentence about SVE2 not being available in hardware --- openpower/sv/comparison_table.mdwn | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/openpower/sv/comparison_table.mdwn b/openpower/sv/comparison_table.mdwn index 8808fac06..1c5e0203b 100644 --- a/openpower/sv/comparison_table.mdwn +++ b/openpower/sv/comparison_table.mdwn @@ -26,7 +26,8 @@ Critically depends on ARM Scalar instructions * (14): difficult to exactly ascertain, see ARM Architecture Reference Manual Supplement, DDI 0584. Critically depends on ARM Scalar instructions. * (15): ARM states that the Scalability is a [Silicon-partner choice](https://developer.arm.com/-/media/Arm%20Developer%20Community/PDF/102340_0001_00_en_introduction-to-sve2.pdf?revision=aae96dd2-5334-4ad3-9a47-393086a20fea). - Scalability in the ISA is **not available to the programmer**: there is no `setvl` instruction in SVE2, which is already causing assembler programmer difficulties. Effectively this makes SVE2 Predicated SIMD where the SIMD width is chosen by the "Silicon partner" + Scalability in the ISA is **not available to the programmer**: there is no `setvl` instruction in SVE2, which is already causing assembler programmer difficulties. Effectively this makes SVE2 Predicated SIMD where the SIMD width is chosen by the "Silicon partner". + **Note that there does not exist publicly-available SVE2 Hardware. Assessing the non-portability of binaries, acknowledge PRIVATELY by ARM Engineers, requires in-depth knowledge of SVE2. This has NOT yet reached public awareness due to world-wide total lack of SVE2 Hardware** * (16): [AVX512 Wikipedia](https://en.wikipedia.org/wiki/AVX-512), [Lifecycle of an instruction set](https://media.handmade-seattle.com/tom-forsyth/) including full slides * (17): difficult to exactly ascertain, contains subsets. Critically depends on ISA support from earlier x86 ISA subsets (several more thousand instructions). See [SIMD ISA listing](https://www.officedaytime.com/simd512e/) * (18): [RVV Spec](https://github.com/riscv/riscv-v-spec/blob/master/v-spec.adoc) -- 2.30.2