From 2e60fba4497ac91609e22e3567e25f57d20bc590 Mon Sep 17 00:00:00 2001 From: lkcl Date: Sun, 23 Jun 2019 16:31:05 +0100 Subject: [PATCH] --- simple_v_extension/sv_prefix_proposal.rst | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/simple_v_extension/sv_prefix_proposal.rst b/simple_v_extension/sv_prefix_proposal.rst index b6ac3affc..7a8d0950a 100644 --- a/simple_v_extension/sv_prefix_proposal.rst +++ b/simple_v_extension/sv_prefix_proposal.rst @@ -15,13 +15,19 @@ Conventions =========== Conventions used in this document: -- Bits are numbered starting from 0 at the LSB, so bit 3 is 1 in the integer 8. -- Bit ranges are inclusive on both ends, so 5:3 means bits 5, 4, and 3. -Operations work on variable-length vectors of sub-vectors, where each sub-vector -has a length *svlen*, and an element type *etype*. When the vectors are stored +* Bits are numbered starting from 0 at the LSB, so bit 3 is 1 in the integer 8. +* Bit ranges are inclusive on both ends, so 5:3 means bits 5, 4, and 3. +* Operations work on variable-length vectors of sub-vectors up to *VL* in length, +where each sub-vector +has a length *svlen*, and *svlen* elements of type *etype*. +* The actual total number of elements is therefore *svlen* times *VL*. +* When the vectors are stored in registers, all elements are packed so that there is no padding in-between -elements of the same vector. The number of bytes in a sub-vector, *svsz*, is the +elements of the same vector. +* The register file itself is thus best viewed as a byte-level +SRAM that is typecast to an array of *etype*s +* The number of bytes in a sub-vector, *svsz*, is the product of *svlen* and the element size in bytes. Options -- 2.30.2