nv50/ir: allow immediate 0 to be loaded anywhere

There's a post-RA fixup to replace 0's with $r63 (or $r127 if too many
regs are used), so just as nvc0, let an immediate 0 be loaded anywhere.

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

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
index 94cf0f0..a0fb144 100644 (file)
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
@@ -268,6 +268,12 @@ TargetNV50::insnCanLoad(const Instruction *i, int s,
 {
    DataFile sf = ld->src(0).getFile();
 
+   // immediate 0 can be represented by GPR $r63/$r127
+   if (sf == FILE_IMMEDIATE && ld->getSrc(0)->reg.data.u64 == 0)
+      return (!i->isPseudo() &&
+              !i->asTex() &&
+              i->op != OP_EXPORT && i->op != OP_STORE);
+
    if (sf == FILE_IMMEDIATE && (i->predSrc >= 0 || i->flagsDef >= 0))
       return false;
    if (s >= opInfo[i->op].srcNr)