Mesa (master): nv50/ir: adjust overlapping logic to take fileIndex-relative offsets

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: 7d56ae5eb2e32e88c90261d6782890ce0c524e7d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7d56ae5eb2e32e88c90261d6782890ce0c524e7d

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Sat Jun 24 17:09:20 2017 -0400

nv50/ir: adjust overlapping logic to take fileIndex-relative offsets

If the fileIndex is different, that means they are in logically
different spaces. However if there's also a relative offset, then they
could end up pointing at the same spot again.

Also add a note about potential for multiple buffers to overlap even if
they're at different file indexes. However that's potentially lowered
away by the point that this logic hits.

Not known to fix any specific application or test.

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

---

 src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index c6dbd4fead..7c4420682a 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -2779,11 +2779,15 @@ MemoryOpt::Record::overlaps(const Instruction *ldst) const
    Record that;
    that.set(ldst);
 
-   if (this->fileIndex != that.fileIndex)
+   // This assumes that images/buffers can't overlap. They can.
+   // TODO: Plumb the restrict logic through, and only skip when it's a
+   // restrict situation, or there can implicitly be no writes.
+   if (this->fileIndex != that.fileIndex && this->rel[1] == that.rel[1])
       return false;
 
    if (this->rel[0] || that.rel[0])
       return this->base == that.base;
+
    return
       (this->offset < that.offset + that.size) &&
       (this->offset + this->size > that.offset);