Mesa (master): nvc0/ir: fix robustness guarantees for constbuf loads on kepler+ compute

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: 1acdd62847cf0da8a8e9c7915d698208d73a5be8
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1acdd62847cf0da8a8e9c7915d698208d73a5be8

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Wed Jan 25 23:48:23 2017 -0500

nvc0/ir: fix robustness guarantees for constbuf loads on kepler+ compute

Kepler and up unfortunately only support up to 8 constbufs. We work
around this by loading from constbufs as if they were storage buffers.
However we were not consistently applying limits to loads from these
buffers. Make sure to do the same thing we do for storage buffers.

Fixes GL45-CTS.robust_buffer_access_behavior.uniform_buffer

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Cc: mesa-stable at lists.freedesktop.org

---

 .../nouveau/codegen/nv50_ir_lowering_nvc0.cpp      | 47 ++++++++++------------
 1 file changed, 22 insertions(+), 25 deletions(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
index 755895d..c71fd69 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -2400,6 +2400,9 @@ NVC0LoweringPass::handleLDST(Instruction *i)
          int8_t fileIndex = i->getSrc(0)->reg.fileIndex - 1;
          Value *ind = i->getIndirect(0, 1);
 
+         if (!ind && fileIndex == -1)
+            return;
+
          if (ind) {
             // Clamp the UBO index when an indirect access is used to avoid
             // loading information from the wrong place in the driver cb.
@@ -2409,32 +2412,26 @@ NVC0LoweringPass::handleLDST(Instruction *i)
                              bld.loadImm(NULL, 12));
          }
 
-         if (i->src(0).isIndirect(1)) {
-            Value *offset = bld.loadImm(NULL, i->getSrc(0)->reg.data.offset + typeSizeof(i->sType));
-            Value *ptr = loadUboInfo64(ind, fileIndex * 16);
-            Value *length = loadUboLength32(ind, fileIndex * 16);
-            Value *pred = new_LValue(func, FILE_PREDICATE);
-            if (i->src(0).isIndirect(0)) {
-               bld.mkOp2(OP_ADD, TYPE_U64, ptr, ptr, i->getIndirect(0, 0));
-               bld.mkOp2(OP_ADD, TYPE_U32, offset, offset, i->getIndirect(0, 0));
-            }
-            i->getSrc(0)->reg.file = FILE_MEMORY_GLOBAL;
-            i->setIndirect(0, 1, NULL);
-            i->setIndirect(0, 0, ptr);
-            bld.mkCmp(OP_SET, CC_GT, TYPE_U32, pred, TYPE_U32, offset, length);
-            i->setPredicate(CC_NOT_P, pred);
-            if (i->defExists(0)) {
-               bld.mkMov(i->getDef(0), bld.mkImm(0));
-            }
-         } else if (fileIndex >= 0) {
-            Value *ptr = loadUboInfo64(ind, fileIndex * 16);
-            if (i->src(0).isIndirect(0)) {
-               bld.mkOp2(OP_ADD, TYPE_U64, ptr, ptr, i->getIndirect(0, 0));
-            }
-            i->getSrc(0)->reg.file = FILE_MEMORY_GLOBAL;
-            i->setIndirect(0, 1, NULL);
-            i->setIndirect(0, 0, ptr);
+         Value *offset = bld.loadImm(NULL, i->getSrc(0)->reg.data.offset + typeSizeof(i->sType));
+         Value *ptr = loadUboInfo64(ind, fileIndex * 16);
+         Value *length = loadUboLength32(ind, fileIndex * 16);
+         Value *pred = new_LValue(func, FILE_PREDICATE);
+         if (i->src(0).isIndirect(0)) {
+            bld.mkOp2(OP_ADD, TYPE_U64, ptr, ptr, i->getIndirect(0, 0));
+            bld.mkOp2(OP_ADD, TYPE_U32, offset, offset, i->getIndirect(0, 0));
          }
+         i->getSrc(0)->reg.file = FILE_MEMORY_GLOBAL;
+         i->setIndirect(0, 1, NULL);
+         i->setIndirect(0, 0, ptr);
+         bld.mkCmp(OP_SET, CC_GT, TYPE_U32, pred, TYPE_U32, offset, length);
+         i->setPredicate(CC_NOT_P, pred);
+         Value *zero, *dst = i->getDef(0);
+         i->setDef(0, bld.getSSA());
+
+         bld.setPosition(i, true);
+         bld.mkMov((zero = bld.getSSA()), bld.mkImm(0))
+            ->setPredicate(CC_P, pred);
+         bld.mkOp2(OP_UNION, TYPE_U32, dst, i->getDef(0), zero);
       } else if (i->src(0).isIndirect(1)) {
          Value *ptr;
          if (i->src(0).isIndirect(0))