Mesa (master): nv50/ir: do not perform global membar for shared memory

[Samuel Pitoiset]

Module: Mesa
Branch: master
Commit: 6dbb8d12a8b78769b9803884fad5f0d9923023bc
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=6dbb8d12a8b78769b9803884fad5f0d9923023bc

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Mon Oct 24 21:41:11 2016 +0200

nv50/ir: do not perform global membar for shared memory

Shared memory is local to CTA, thus we should only wait for
prior memory writes which are visible to other threads in
the same CTA, and not at global level. This should speedup
compute shaders which use shared memory.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>

---

 src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
index b47fc49..91cef81 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
@@ -3561,12 +3561,15 @@ Converter::handleInstruction(const struct tgsi_full_instruction *insn)
       geni->subOp = tgsi::opcodeToSubOp(tgsi.getOpcode());
       break;
    case TGSI_OPCODE_MEMBAR:
+   {
+      uint32_t level = tgsi.getSrc(0).getValueU32(0, info);
       geni = mkOp(OP_MEMBAR, TYPE_NONE, NULL);
       geni->fixed = 1;
-      if (tgsi.getSrc(0).getValueU32(0, info) & TGSI_MEMBAR_THREAD_GROUP)
+      if (!(level & ~(TGSI_MEMBAR_THREAD_GROUP | TGSI_MEMBAR_SHARED)))
          geni->subOp = NV50_IR_SUBOP_MEMBAR(M, CTA);
       else
          geni->subOp = NV50_IR_SUBOP_MEMBAR(M, GL);
+   }
       break;
    case TGSI_OPCODE_ATOMUADD:
    case TGSI_OPCODE_ATOMXCHG: