From f98c3f3e44abb0c8cb158c589418def111d72052 Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Fri, 8 May 2015 16:13:52 +0100 Subject: [PATCH] i965/fs: Improve a comment about stripping trailing zeroes Originally I wrote that removing the first parameter doesn't work but I didn't know why. I now found a mention of this in the PRM so it's probably worthing adding it to the comment. --- src/mesa/drivers/dri/i965/brw_fs.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 8dd680e1ae3..b2701b89689 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -2600,9 +2600,12 @@ fs_visitor::opt_zero_samples() load_payload->opcode != SHADER_OPCODE_LOAD_PAYLOAD) continue; - /* We don't want to remove the message header. Removing all of the - * parameters is avoided because it seems to cause a GPU hang but I - * can't find any documentation indicating that this is expected. + /* We don't want to remove the message header or the first parameter. + * Removing the first parameter is not allowed, see the Haswell PRM + * volume 7, page 149: + * + * "Parameter 0 is required except for the sampleinfo message, which + * has no parameter 0" */ while (inst->mlen > inst->header_size + dispatch_width / 8 && load_payload->src[(inst->mlen - inst->header_size) / -- 2.30.2