Mesa (master): nvc0/ir: Handle OP_BFIND when folding constant expressions

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: fdc1d96b0ff59e163ed9fe894a1e6d08d4204b94
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=fdc1d96b0ff59e163ed9fe894a1e6d08d4204b94

Author: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
Date:   Wed Jun  4 00:35:49 2014 +0200

nvc0/ir: Handle OP_BFIND when folding constant expressions

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>

---

 .../drivers/nouveau/codegen/nv50_ir_peephole.cpp      |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index 5254617..a91d698 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -940,6 +940,23 @@ 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;
+      bld.setPosition(i, false); /* make sure bld is init'ed */
+      i->setSrc(0, bld.mkImm(res));
+      i->setSrc(1, NULL);
+      i->op = OP_MOV;
+      i->subOp = 0;
+      break;
+   }
    default:
       return;
    }