From 68137939abb99541f85b0e8e730a8aa227004c54 Mon Sep 17 00:00:00 2001 From: TimothyLottes Date: Wed, 9 Nov 2016 19:26:49 -0500 Subject: [PATCH] Add files via upload --- 20160706.html | 30 ++++++++++++++++++++++++++++++ index.html | 1 + 2 files changed, 31 insertions(+) create mode 100644 20160706.html diff --git a/20160706.html b/20160706.html new file mode 100644 index 0000000..66c1857 --- /dev/null +++ b/20160706.html @@ -0,0 +1,30 @@ +
+

20160706 - Low Cost Branching to Factoring Out Loop Exit Check

+
+ + + +Threading to hide pipeline depth combined with an ISA which makes branching cheep is one goal. +Specifically absolute branching with immediate destination in the opcode word +(single word branch/call, no adder), and instructions which include a return flag (make returns free). +Enables easy computed branches, both for jump tables, and loops. +Can factor out loop check into hierarchical call tree, +
+
+Do4: Unroll work four times; Return;
+Do16: Call Do4; Call Do4; Call Do4; Jump Do4;
+Do64: Call Do16; Call Do16; Call Do16; Jump Do16;
+... etc ... +
+
+Can use a computed branch to jump into the tree for other loop counts. + + + + + + +
+ + + diff --git a/index.html b/index.html index c340c89..2435f39 100644 --- a/index.html +++ b/index.html @@ -71,6 +71,7 @@ Below this is active random migration (456 prior posts still to filter through) 20160721 - Why Motion Blur Trivially Breaks Tone-Mapping - Part 1
20160720 - Re Twitter: Thoughts on Vulkan Command Buffers
20160715 - LED Displays
+20160706 - Low Cost Branching to Factoring Out Loop Exit Check
20160127 - Temporal AA Neighborhood Clamp

2015