From 5c00f170f1c1163e0a73ce4219117cbf16462863 Mon Sep 17 00:00:00 2001 From: lkcl Date: Sat, 16 Jan 2021 12:47:10 +0000 Subject: [PATCH] --- 3d_gpu/architecture/dynamic_simd/logicops.mdwn | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/3d_gpu/architecture/dynamic_simd/logicops.mdwn b/3d_gpu/architecture/dynamic_simd/logicops.mdwn index 9fa4ca8e6..73719431f 100644 --- a/3d_gpu/architecture/dynamic_simd/logicops.mdwn +++ b/3d_gpu/architecture/dynamic_simd/logicops.mdwn @@ -70,9 +70,9 @@ the second observation then is that, actually, just like the other partitioned o Exactly the same as for eq, instead the "xor" operator for example is the amalgamation of 4 partial results, x0 to x3. - partition: P P P (3 bits) - a : .... .... .... .... (32 bits) - xor-a : x0 P x1 P x2 P x3 (4+3 bits, P=1 if no partition) + partition: P P P (3 partition bits) + a : .... .... .... .... (32 input bits) + xor-a : x0 P x1 P x2 P x3 (4+3 bits, P=0 "breaks") x0 = input[0:7].xor() x1 = input[8:15].xor() @@ -98,6 +98,11 @@ Example: when p2p1p0 == 101 this indicates -* that the output is to contain an XOR of the top 8 bits, the middle 16 bits, and the low 8 bits. this in a 4 bit result (o3o2o1o0) divided into `o3`, `o2o1` and `o0` -* the top bit of the 4-bit answer contains x3, the middle 2 bits contain the XOR or x1 and x2, the first bit contains x0. -* therefore, the final result: the top bit contains the XOR of the input bits 24 to 31, the middle 2 bits contains the XOR of bits 8 to 15, the lowest bit contains the XOR of bits 0 to 7. +* that the output is to contain an XOR of the top 8 bits, the middle 16 bits, and the low 8 bits. this in a 4 bit result (`o3o2o1o0`) divided into `o3`, `o2o1` and `o0` + - the top bit of the 4-bit answer contains x3 + - the middle 2 bits contain the XOR of x1 and x2 + - the first bit contains x0. +* therefore, the final result: + - the top bit contains the XOR of the input bits 24 to 31 + - the middle 2 bits contains the XOR of bits 8 to 15 + - the lowest bit contains the XOR of bits 0 to 7. -- 2.30.2