Nouveau - Jul 2014 - [PATCH 1/2] nvc0/ir: use manual TXD when offsets are involved

Something about how we're implementing offsets for TXD is wrong, just
flip to the generic quadop-based implementation in that case.

This is the minimal fix appropriate for backporting.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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 0e24db7..398b28f 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -769,7 +769,8 @@ NVC0LoweringPass::handleTXD(TexInstruction *txd)
    if (dim > 2 ||
        txd->tex.target.isCube() ||
        arg > 4 ||
-       txd->tex.target.isShadow())
+       txd->tex.target.isShadow() ||
+       txd->tex.useOffsets)
       return handleManualTXD(txd);
 
    for (int c = 0; c < dim; ++c) {
-- 
1.8.5.5

Apparently TXD wants its offset differently than TEX, accepting it in
the upper bits of the layer index. Unclear what happens when this is
combined with indirect sampler indexing.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 .../nouveau/codegen/nv50_ir_lowering_nvc0.cpp      | 47 ++++++++++++++++------
 1 file changed, 34 insertions(+), 13 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 398b28f..ac2a770 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -639,12 +639,14 @@ NVC0LoweringPass::handleTEX(TexInstruction *i)
    if (i->tex.useOffsets) {
       int n, c;
       int s = i->srcCount(0xff, true);
-      if (i->tex.target.isShadow())
-         s--;
-      if (i->srcExists(s)) // move potential predicate out of the way
-         i->moveSources(s, 1);
-      if (i->tex.useOffsets == 4 && i->srcExists(s + 1))
-         i->moveSources(s + 1, 1);
+      if (i->op != OP_TXD) {
+         if (i->tex.target.isShadow())
+            s--;
+         if (i->srcExists(s)) // move potential predicate out of the way
+            i->moveSources(s, 1);
+         if (i->tex.useOffsets == 4 && i->srcExists(s + 1))
+            i->moveSources(s + 1, 1);
+      }
       if (i->op == OP_TXG) {
          // Either there is 1 offset, which goes into the 2 low bytes of the
          // first source, or there are 4 offsets, which go into 2 sources (8
@@ -673,7 +675,22 @@ NVC0LoweringPass::handleTEX(TexInstruction *i)
             assert(i->offset[0][c].getImmediate(val));
             imm |= (val.reg.data.u32 & 0xf) << (c * 4);
          }
-         i->setSrc(s, bld.loadImm(NULL, imm));
+         if (i->op == OP_TXD) {
+            // The offset goes into the upper 16 bits of the array index. So
+            // create it if it's not already there, and INSBF it if it
already
+            // is.
+            if (i->tex.target.isArray()) {
+               bld.mkOp3(OP_INSBF, TYPE_U32, i->getSrc(0),
+                         bld.loadImm(NULL, imm), bld.mkImm(0xc10),
+                         i->getSrc(0));
+            } else {
+               for (int s = dim; s >= 1; --s)
+                  i->setSrc(s, i->getSrc(s - 1));
+               i->setSrc(0, bld.loadImm(NULL, imm << 16));
+            }
+         } else {
+            i->setSrc(s, bld.loadImm(NULL, imm));
+         }
       }
    }
 
@@ -759,20 +776,24 @@ bool
 NVC0LoweringPass::handleTXD(TexInstruction *txd)
 {
    int dim = txd->tex.target.getDim();
-   int arg = txd->tex.target.getArgCount();
+   unsigned arg = txd->tex.target.getArgCount();
+   unsigned expected_args = arg;
+
+   if (!txd->tex.target.isArray() && txd->tex.useOffsets)
+      expected_args++;
+
+   if (expected_args > 4 || dim > 2 || txd->tex.target.isShadow())
+      txd->op = OP_TEX;
 
    handleTEX(txd);
    while (txd->srcExists(arg))
       ++arg;
 
    txd->tex.derivAll = true;
-   if (dim > 2 ||
-       txd->tex.target.isCube() ||
-       arg > 4 ||
-       txd->tex.target.isShadow() ||
-       txd->tex.useOffsets)
+   if (txd->op == OP_TEX)
       return handleManualTXD(txd);
 
+   assert(arg == expected_args);
    for (int c = 0; c < dim; ++c) {
       txd->setSrc(arg + c * 2 + 0, txd->dPdx[c]);
       txd->setSrc(arg + c * 2 + 1, txd->dPdy[c]);
-- 
1.8.5.5