[Nouveau] [PATCH v2 2/4] nvc0/ir: Handle reverse subop for OP_EXTBF when folding constant expressions

[Tobias Klausmann]

V2: Handle the instruction right (shift after reverse)

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
---
 src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index 58092f4..a214ffc 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -529,8 +529,20 @@ ConstantFolding::expr(Instruction *i,
          lshift = 32 - width - offset;
       }
       switch (i->dType) {
-      case TYPE_S32: res.data.s32 = (a->data.s32 << lshift) >> rshift; break;
-      case TYPE_U32: res.data.u32 = (a->data.u32 << lshift) >> rshift; break;
+      case TYPE_S32:
+         if (i->subOp == NV50_IR_SUBOP_EXTBF_REV)
+            res.data.s32 = util_bitreverse(a->data.s32);
+         else
+            res.data.s32 = a->data.s32;
+         res.data.s32 = (res.data.s32 << lshift) >> rshift;
+         break;
+      case TYPE_U32:
+         if (i->subOp == NV50_IR_SUBOP_EXTBF_REV)
+            res.data.u32 = util_bitreverse(a->data.u32);
+         else
+            res.data.u32 = a->data.u32;
+         res.data.u32 = (res.data.u32 << lshift) >> rshift;
+         break;
       default:
          return;
       }
-- 
1.8.4.5