From: Michael LeBeane <Michael.Lebeane@amd.com>
Date: Mon, 20 May 2019 20:39:40 +0000 (-0400)
Subject: arch-gcn3: Fix stride bug in buffer OOB detection logic
X-Git-Tag: v20.1.0.0~426
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f509fa735ca7a2969c99fd9606157ba72a4abe9c;p=gem5.git

arch-gcn3: Fix stride bug in buffer OOB detection logic

The out-of-range logic for buffer accesses is missing the top 4 bits of
const_stride when dealing with scratch buffers.  This can cause
perfectly valid scratch acceses to be suppressed when const_stride is
large.

Change-Id: I8f94d44c242fda26cf6dfb75db04fa3aca934b3e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29968
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---

diff --git a/src/arch/gcn3/insts/op_encodings.hh b/src/arch/gcn3/insts/op_encodings.hh
index 202dd1d82..b35fb3d68 100644
--- a/src/arch/gcn3/insts/op_encodings.hh
+++ b/src/arch/gcn3/insts/op_encodings.hh
@@ -651,7 +651,7 @@ namespace Gcn3ISA
                      * non-formatted accesses, this is done on a per-lane
                      * basis.
                      */
-                    if (rsrc_desc.stride == 0 || !rsrc_desc.swizzleEn) {
+                    if (stride == 0 || !rsrc_desc.swizzleEn) {
                         if (buf_off + stride * buf_idx >=
                             rsrc_desc.numRecords - s_offset.rawData()) {
                             DPRINTF(GCN3, "mubuf out-of-bounds condition 1: "
@@ -659,13 +659,13 @@ namespace Gcn3ISA
                                     "const_stride = %llx, "
                                     "const_num_records = %llx\n",
                                     lane, buf_off + stride * buf_idx,
-                                    rsrc_desc.stride, rsrc_desc.numRecords);
+                                    stride, rsrc_desc.numRecords);
                             oobMask.set(lane);
                             continue;
                         }
                     }
 
-                    if (rsrc_desc.stride != 0 && rsrc_desc.swizzleEn) {
+                    if (stride != 0 && rsrc_desc.swizzleEn) {
                         if (buf_idx >= rsrc_desc.numRecords ||
                             buf_off >= stride) {
                             DPRINTF(GCN3, "mubuf out-of-bounds condition 2: "