From 0e755f99641da55baf52419a46f241f54ccc671a Mon Sep 17 00:00:00 2001
From: Faith Ekstrand <faith.ekstrand@collabora.com>
Date: Mon, 30 Jan 2023 20:53:17 -0600
Subject: [PATCH] nak: Implement bcsel

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24998>
---
 src/nouveau/compiler/nak_encode_tu102.rs | 9 +++++++++
 src/nouveau/compiler/nak_from_nir.rs     | 4 ++++
 src/nouveau/compiler/nak_ir.rs           | 7 +++++++
 3 files changed, 20 insertions(+)

diff --git a/src/nouveau/compiler/nak_encode_tu102.rs b/src/nouveau/compiler/nak_encode_tu102.rs
index 55b29a77d6f..fd3d179447a 100644
--- a/src/nouveau/compiler/nak_encode_tu102.rs
+++ b/src/nouveau/compiler/nak_encode_tu102.rs
@@ -216,6 +216,14 @@ fn encode_mov(bs: &mut impl BitSetMut, instr: &Instr) {
     bs.set_field(72..76, 0xf_u32 /* TODO: Quad lanes */);
 }
 
+fn encode_sel(bs: &mut impl BitSetMut, instr: &Instr) {
+    let i = Instr::new(Opcode::SEL, instr.dsts(), &instr.srcs()[1..]);
+    encode_alu(bs, &i, 0x007);
+
+    encode_pred(bs, 87..90, *instr.src(0).as_reg().unwrap());
+    bs.set_bit(90, false); /* not */
+}
+
 fn encode_iadd3(bs: &mut impl BitSetMut, instr: &Instr) {
     encode_alu(bs, instr, 0x010);
 
@@ -377,6 +385,7 @@ pub fn encode_instr(instr: &Instr) -> [u32; 4] {
     match &instr.op {
         Opcode::S2R(i) => encode_s2r(&mut bs, instr, *i),
         Opcode::MOV => encode_mov(&mut bs, instr),
+        Opcode::SEL => encode_sel(&mut bs, instr),
         Opcode::IADD3 => encode_iadd3(&mut bs, instr),
         Opcode::LOP3(op) => encode_lop3(&mut bs, instr, &op),
         Opcode::ISETP(op) => encode_isetp(&mut bs, instr, &op),
diff --git a/src/nouveau/compiler/nak_from_nir.rs b/src/nouveau/compiler/nak_from_nir.rs
index 12a413b9c3f..562ca7d1701 100644
--- a/src/nouveau/compiler/nak_from_nir.rs
+++ b/src/nouveau/compiler/nak_from_nir.rs
@@ -86,6 +86,10 @@ impl<'a> ShaderFromNir<'a> {
         let dst = self.get_dst(&alu.def);
 
         match alu.op {
+            nir_op_bcsel => {
+                self.instrs
+                    .push(Instr::new_sel(dst, srcs[0], srcs[1], srcs[2]));
+            }
             nir_op_fadd => {
                 self.instrs.push(Instr::new_fadd(dst, srcs[0], srcs[1]));
             }
diff --git a/src/nouveau/compiler/nak_ir.rs b/src/nouveau/compiler/nak_ir.rs
index 09979c4b969..27fe161fe58 100644
--- a/src/nouveau/compiler/nak_ir.rs
+++ b/src/nouveau/compiler/nak_ir.rs
@@ -832,6 +832,10 @@ impl Instr {
         Instr::new(Opcode::MOV, slice::from_ref(&dst), &[Src::Zero, src])
     }
 
+    pub fn new_sel(dst: Dst, sel: Src, x: Src, y: Src) -> Instr {
+        Instr::new(Opcode::SEL, slice::from_ref(&dst), &[sel, x, y])
+    }
+
     pub fn new_vec(dst: Dst, srcs: &[Src]) -> Instr {
         Instr::new(Opcode::VEC, slice::from_ref(&dst), srcs)
     }
@@ -946,6 +950,7 @@ impl Instr {
             | Opcode::ISETP(_)
             | Opcode::SHL => Some(6),
             Opcode::MOV => Some(15),
+            Opcode::SEL => Some(15),
             Opcode::S2R(_) => None,
             Opcode::ALD(_) => None,
             Opcode::AST(_) => Some(15),
@@ -996,6 +1001,7 @@ pub enum Opcode {
 
     S2R(u8),
     MOV,
+    SEL,
     VEC,
     SPLIT,
 
@@ -1024,6 +1030,7 @@ impl fmt::Display for Opcode {
             Opcode::SHL => write!(f, "SHL"),
             Opcode::S2R(i) => write!(f, "S2R({})", i),
             Opcode::MOV => write!(f, "MOV"),
+            Opcode::SEL => write!(f, "SEL"),
             Opcode::VEC => write!(f, "VEC"),
             Opcode::SPLIT => write!(f, "SPLIT"),
             Opcode::ALD(_) => write!(f, "ALD"),