From 6041e3b07a891fe89c3b2081ce212022f0d40d33 Mon Sep 17 00:00:00 2001 From: Lionel Landwerlin Date: Wed, 17 Mar 2021 21:30:52 +0200 Subject: [PATCH] intel/fs/vec4: add missing dependency in write-on-write fixed GRFs If we load constant data using pull constant SENDS, and we later load that register with some other data, we can end up in a situation where we don't track the initial fixed register write and therefore end up using uninitialized registers. This tracks write-on-write of fixed GRFs like we do for normal virtual GRFs. v2: Fix post_alloc_reg case (Jason) Signed-off-by: Lionel Landwerlin Cc: Reviewed-by: Francisco Jerez Reviewed-by: Jason Ekstrand Part-of: (cherry picked from commit 8b6d22109f452b05ab1ce2028f7e18e50edcf325) --- .pick_status.json | 2 +- src/intel/compiler/brw_schedule_instructions.cpp | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/.pick_status.json b/.pick_status.json index 7755dcad87e..88623d93c96 100644 --- a/.pick_status.json +++ b/.pick_status.json @@ -985,7 +985,7 @@ "description": "intel/fs/vec4: add missing dependency in write-on-write fixed GRFs", "nominated": true, "nomination_type": 0, - "resolution": 0, + "resolution": 1, "master_sha": null, "because_sha": null }, diff --git a/src/intel/compiler/brw_schedule_instructions.cpp b/src/intel/compiler/brw_schedule_instructions.cpp index d9f6f9d852f..d7c2230e8e1 100644 --- a/src/intel/compiler/brw_schedule_instructions.cpp +++ b/src/intel/compiler/brw_schedule_instructions.cpp @@ -1188,9 +1188,12 @@ fs_instruction_scheduler::calculate_deps() } } else if (inst->dst.file == FIXED_GRF) { if (post_reg_alloc) { - for (unsigned r = 0; r < regs_written(inst); r++) + for (unsigned r = 0; r < regs_written(inst); r++) { + add_dep(last_grf_write[inst->dst.nr + r], n); last_grf_write[inst->dst.nr + r] = n; + } } else { + add_dep(last_fixed_grf_write, n); last_fixed_grf_write = n; } } else if (inst->dst.is_accumulator()) { @@ -1418,6 +1421,7 @@ vec4_instruction_scheduler::calculate_deps() add_dep(last_mrf_write[inst->dst.nr], n); last_mrf_write[inst->dst.nr] = n; } else if (inst->dst.file == FIXED_GRF) { + add_dep(last_fixed_grf_write, n); last_fixed_grf_write = n; } else if (inst->dst.is_accumulator()) { add_dep(last_accumulator_write, n);