From 8fde30925d9c13df9003ab34bd8fafe404ff2284 Mon Sep 17 00:00:00 2001 From: Alyssa Rosenzweig Date: Mon, 1 Mar 2021 19:55:07 +0000 Subject: [PATCH] pan/bi: Document register conventions Should motiviate RA decisions. Signed-off-by: Alyssa Rosenzweig Part-of: --- src/panfrost/bifrost/README.md | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 src/panfrost/bifrost/README.md diff --git a/src/panfrost/bifrost/README.md b/src/panfrost/bifrost/README.md new file mode 100644 index 00000000000..2838d41846f --- /dev/null +++ b/src/panfrost/bifrost/README.md @@ -0,0 +1,25 @@ +# Bifrost compiler + +## Register file + +Defined partially in software, partially in hardware. + +## Blend shaders + +R0 - R3: input (color #0) +R4 - R7: input (color #1) +R8 - R15: general purpose +R48: return address + +## Fragment + +Anything live during BLEND must respect blend shader registers. + +R0 - R3: preloaded (message #0) +R4 - R7: preloaded (message #1) +R57 - R63: preloaded (various) + +R0 - R15: general purpose (full threads) +R48 - R63: general purpose (full threads) + +R32 - R47: general purpose (half threads, or v6)