[Mesa-dev] [PATCH v2 3/4] nvc0/ir: Handle OP_BFIND when folding constant expressions

[Tobias Klausmann]

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
---
 .../drivers/nouveau/codegen/nv50_ir_peephole.cpp       | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index a214ffc..c497335 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -948,6 +948,24 @@ ConstantFolding::opnd(Instruction *i, ImmediateValue &imm0, int s)
    case OP_EX2:
       unary(i, imm0);
       break;
+   case OP_BFIND: {
+      int32_t res;
+      switch (i->dType) {
+      case TYPE_S32:
+         res = util_last_bit_signed(imm0.reg.data.s32) - 1; break;
+      case TYPE_U32:
+         res = util_last_bit(imm0.reg.data.u32) -1; break;
+      default:
+         return;
+      }
+      if ((i->subOp ==  NV50_IR_SUBOP_BFIND_SAMT) && (res >= 0))
+         res = 31 - res;
+      i->setSrc(0, new_ImmediateValue(i->bb->getProgram(), (uint32_t)res));
+      i->setSrc(1, NULL);
+      i->op = OP_MOV;
+      i->subOp = 0;
+      break;
+   }
    default:
       return;
    }
-- 
1.8.4.5