From: Rhys Perry <pendingchaos02@gmail.com>
Date: Thu, 11 Jun 2020 14:38:07 +0000 (+0100)
Subject: aco: don't create byte-aligned short loads
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=91d7e40176328d0a256d9b9cf0ff749604035c51;p=mesa.git

aco: don't create byte-aligned short loads

The ISA docs don't seem to say if this is allowed, so just assume short
loads require short alignment.

In practice, the only situation this should affect are byte-aligned u8vec2
loads.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5207>
---

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index b36c41d8474..0af920b5629 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -3111,7 +3111,9 @@ void emit_load(isel_context *ctx, Builder& bld, const LoadEmitInfo *info)
       int byte_align = align_mul % 4 == 0 ? align_offset % 4 : -1;
 
       if (byte_align) {
-         if ((bytes_needed > 2 || !supports_8bit_16bit_loads) && byte_align_loads) {
+         if ((bytes_needed > 2 ||
+              (bytes_needed == 2 && (align_mul % 2 || align_offset % 2)) ||
+              !supports_8bit_16bit_loads) && byte_align_loads) {
             if (info->component_stride) {
                assert(supports_8bit_16bit_loads && "unimplemented");
                bytes_needed = 2;