gk110/ir: do not overwrite def value with zero for EXCH ops

This is only valid for other atomic operations (including CAS). This
fixes an invalid opcode error from dmesg. While we are it, make sure
to initialize global addr to 0 for other atomic operations.

Signed-off-by: Samuel Pitoiset <[email protected]>
Reviewed-by: Ilia Mirkin <[email protected]>
Cc: "11.1 11.2" <[email protected]>

1 files changed, 15 insertions, 6 deletions

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
index 70f3c3f69ff..e2c3b8ef14d 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
@@ -1808,6 +1808,9 @@ uses64bitAddress(const Instruction *ldst)
 void
 CodeEmitterGK110::emitATOM(const Instruction *i)
 {
+   const bool hasDst = i->defExists(0);
+   const bool exch = i->subOp == NV50_IR_SUBOP_ATOM_EXCH;
+
    code[0] = 0x00000002;
    if (i->subOp == NV50_IR_SUBOP_ATOM_CAS)
       code[1] = 0x77800000;
@@ -1836,15 +1839,21 @@ CodeEmitterGK110::emitATOM(const Instruction *i)
    /* TODO: cas: flip bits if $r255 is used */
    srcId(i->src(1), 23);
 
-   if (i->defExists(0))
+   if (hasDst) {
       defId(i->def(0), 2);
-   else
+   } else
+   if (!exch) {
       code[0] |= 255 << 2;
+   }
 
-   const int32_t offset = SDATA(i->src(0)).offset;
-   assert(offset < 0x80000 && offset >= -0x80000);
-   code[0] |= (offset & 1) << 31;
-   code[1] |= (offset & 0xffffe) >> 1;
+   if (hasDst || !exch) {
+      const int32_t offset = SDATA(i->src(0)).offset;
+      assert(offset < 0x80000 && offset >= -0x80000);
+      code[0] |= (offset & 1) << 31;
+      code[1] |= (offset & 0xffffe) >> 1;
+   } else {
+      srcAddr32(i->src(0), 31);
+   }
 
    if (i->getIndirect(0, 0)) {
       srcId(i->getIndirect(0, 0), 10);