[Mesa-dev] [PATCH] nv50/ir: fix moves to/from flags

[Ilia Mirkin]

Noticed this when looking at a trace that caused flags to spill to/from
registers. The flags source/destination wasn't encoded correctly
according to both envydis and nvdisasm.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---

Untested. Will try a few things before pushing this... hopefully it
fixes some stubborn traces, but I'm not too hopeful.

The TGSI program I happened to be looking at was from
https://github.com/iXit/Mesa-3D/issues/160 (fallout new vegas). The
bug in question is totally unrelated though, it was about spilling on
fermi/kepler1.

 src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp | 5 +++--
 src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp        | 4 ++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
index 0b52882..216e119 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
@@ -756,10 +756,10 @@ CodeEmitterNV50::emitMOV(const Instruction *i)
    assert(sf == FILE_GPR || df == FILE_GPR);
 
    if (sf == FILE_FLAGS) {
+      assert(i->flagsSrc >= 0);
       code[0] = 0x00000001;
       code[1] = 0x20000000;
       defId(i->def(0), 2);
-      srcId(i->src(0), 12);
       emitFlagsRd(i);
    } else
    if (sf == FILE_ADDRESS) {
@@ -770,11 +770,12 @@ CodeEmitterNV50::emitMOV(const Instruction *i)
       emitFlagsRd(i);
    } else
    if (df == FILE_FLAGS) {
+      assert(i->flagsDef >= 0);
       code[0] = 0x00000001;
       code[1] = 0xa0000000;
-      defId(i->def(0), 4);
       srcId(i->src(0), 9);
       emitFlagsRd(i);
+      emitFlagsWr(i);
    } else
    if (sf == FILE_IMMEDIATE) {
       code[0] = 0x10008001;
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
index 41d2cc9..d176f31 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
@@ -1599,6 +1599,8 @@ SpillCodeInserter::spill(Instruction *defi, Value *slot, LValue *lval)
       st = new_Instruction(func, OP_CVT, ty);
       st->setDef(0, slot);
       st->setSrc(0, lval);
+      if (lval->reg.file == FILE_FLAGS)
+         st->flagsSrc = 0;
    }
    defi->bb->insertAfter(defi, st);
 }
@@ -1640,6 +1642,8 @@ SpillCodeInserter::unspill(Instruction *usei, LValue *lval, Value *slot)
    }
    ld->setDef(0, lval);
    ld->setSrc(0, slot);
+   if (lval->reg.file == FILE_FLAGS)
+      ld->flagsDef = 0;
 
    usei->bb->insertBefore(usei, ld);
    return lval;
-- 
2.4.10