diff options
| author | Ben Widawsky <[email protected]> | 2014-12-02 17:30:49 -0800 |
|---|---|---|
| committer | Ben Widawsky <[email protected]> | 2015-02-06 17:54:17 -0800 |
| commit | 8030e269e911c4f90a44d9a77eb342dd2657d229 (patch) | |
| tree | 0948855b74b40f502bb0cb4a1baa80bfd90a0d78 | |
| parent | e660f0dd807d028c8088c5c9bedf64a8bebc361b (diff) | |
i965/vec4: Correct MUL destination hazard
As it turns out, we were over-thinking the cause of the hang on
Cherryview. It's simply errata for Cherryview.
commit 88fea85f09e2252035bec66ab26c375b45b000f5
Author: Ben Widawsky <[email protected]>
Date: Fri Nov 21 10:47:41 2014 -0800
i965/vec4/gen8: Handle the MUL dest hazard exception
This is an explanation to why we never saw the hang on BDW.
NOTE: The problem the original patch was trying to fix does still exist. It will
have to be fixed at some point.
v2: Modify commit message, s/CHV/BDW
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84212
Signed-off-by: Ben Widawsky <[email protected]>
Reviewed-by: Matt Turner <[email protected]>
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_vec4.cpp | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp index 89881967dfd..98fad6c8f87 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp @@ -822,11 +822,11 @@ vec4_visitor::is_dep_ctrl_unsafe(const vec4_instruction *inst) (reg.type == BRW_REGISTER_TYPE_UD || \ reg.type == BRW_REGISTER_TYPE_D) - /* From the destination hazard section of the spec: - * > Instructions other than send, may use this control as long as operations - * > that have different pipeline latencies are not mixed. + /* "When source or destination datatype is 64b or operation is integer DWord + * multiply, DepCtrl must not be used." + * May apply to future SoCs as well. */ - if (brw->gen >= 8) { + if (brw->is_cherryview) { if (inst->opcode == BRW_OPCODE_MUL && IS_DWORD(inst->src[0]) && IS_DWORD(inst->src[1])) |