nak: Implement i2f

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24998>

src/nouveau/compiler/nak_encode_sm75.rs

@@ -357,6 +357,24 @@ impl SM75Instr {
         self.set_bit(80, false /* HI */);
     }
 
+    fn encode_i2f(&mut self, op: &OpI2F) {
+        self.encode_alu(0x106, Some(op.dst), None, op.src.into(), None);
+
+        self.set_field(60..62, 0_u8); /* TODO: subop */
+        self.set_bit(74, op.src_type.is_signed());
+        self.set_field(75..77, op.dst_type.bytes().trailing_zeros());
+        self.set_field(
+            78..80,
+            match op.rnd_mode {
+                FRndMode::NearestEven => 0_u8,
+                FRndMode::NegInf => 1_u8,
+                FRndMode::PosInf => 2_u8,
+                FRndMode::Zero => 3_u8,
+            },
+        );
+        self.set_field(84..86, op.src_type.bytes().trailing_zeros());
+    }
+
     fn encode_mov(&mut self, op: &OpMov) {
         self.encode_alu(0x002, Some(op.dst), None, op.src.into(), None);
         self.set_field(72..76, op.quad_lanes);
@@ -515,6 +533,7 @@ impl SM75Instr {
             Op::ISetP(op) => si.encode_isetp(&op),
             Op::Lop3(op) => si.encode_lop3(&op),
             Op::Shl(op) => si.encode_shl(&op),
+            Op::I2F(op) => si.encode_i2f(&op),
             Op::Mov(op) => si.encode_mov(&op),
             Op::Sel(op) => si.encode_sel(&op),
             Op::PLop3(op) => si.encode_plop3(&op),

src/nouveau/compiler/nak_from_nir.rs

@@ -90,6 +90,9 @@ impl<'a> ShaderFromNir<'a> {
                 self.instrs
                     .push(Instr::new_sel(dst, srcs[0], srcs[1], srcs[2]));
             }
+            nir_op_i2f32 => {
+                self.instrs.push(Instr::new_i2f(dst, srcs[0]));
+            }
             nir_op_iadd => {
                 self.instrs.push(Instr::new_iadd(dst, srcs[0], srcs[1]));
             }

src/nouveau/compiler/nak_ir.rs

@@ -545,6 +545,94 @@ impl fmt::Display for LogicOp {
     }
 }
 
+pub enum FloatType {
+    F16,
+    F32,
+    F64,
+}
+
+impl FloatType {
+    pub fn bytes(&self) -> usize {
+        match self {
+            FloatType::F16 => 2,
+            FloatType::F32 => 4,
+            FloatType::F64 => 8,
+        }
+    }
+}
+
+impl fmt::Display for FloatType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            FloatType::F16 => write!(f, "F16"),
+            FloatType::F32 => write!(f, "F32"),
+            FloatType::F64 => write!(f, "F64"),
+        }
+    }
+}
+
+pub enum FRndMode {
+    NearestEven,
+    NegInf,
+    PosInf,
+    Zero,
+}
+
+impl fmt::Display for FRndMode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            FRndMode::NearestEven => write!(f, "RE"),
+            FRndMode::NegInf => write!(f, "RM"),
+            FRndMode::PosInf => write!(f, "RP"),
+            FRndMode::Zero => write!(f, "RZ"),
+        }
+    }
+}
+
+pub enum IntType {
+    U8,
+    I8,
+    U16,
+    I16,
+    U32,
+    I32,
+    U64,
+    I64,
+}
+
+impl IntType {
+    pub fn is_signed(&self) -> bool {
+        match self {
+            IntType::U8 | IntType::U16 | IntType::U32 | IntType::U64 => false,
+            IntType::I8 | IntType::I16 | IntType::I32 | IntType::I64 => true,
+        }
+    }
+
+    pub fn bytes(&self) -> usize {
+        match self {
+            IntType::U8 | IntType::I8 => 1,
+            IntType::U16 | IntType::I16 => 2,
+            IntType::U32 | IntType::I32 => 4,
+            IntType::U64 | IntType::I64 => 8,
+        }
+    }
+}
+
+impl fmt::Display for IntType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            IntType::U8 => write!(f, "U8"),
+            IntType::I8 => write!(f, "I8"),
+            IntType::U16 => write!(f, "U16"),
+            IntType::I16 => write!(f, "I16"),
+            IntType::U32 => write!(f, "U32"),
+            IntType::I32 => write!(f, "I32"),
+            IntType::U64 => write!(f, "U64"),
+            IntType::I64 => write!(f, "I64"),
+        }
+    }
+}
+
 pub enum MemAddrType {
     A32,
     A64,
@@ -751,6 +839,26 @@ impl fmt::Display for OpShl {
     }
 }
 
+#[repr(C)]
+#[derive(SrcsAsSlice, DstsAsSlice, SrcModsAsSlice)]
+pub struct OpI2F {
+    pub dst: Dst,
+    pub src: Src,
+    pub dst_type: FloatType,
+    pub src_type: IntType,
+    pub rnd_mode: FRndMode,
+}
+
+impl fmt::Display for OpI2F {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "I2F.{}.{}.{} {} {}",
+            self.dst_type, self.src_type, self.rnd_mode, self.dst, self.src,
+        )
+    }
+}
+
 #[repr(C)]
 #[derive(SrcsAsSlice, DstsAsSlice, SrcModsAsSlice)]
 pub struct OpMov {
@@ -1011,6 +1119,7 @@ pub enum Op {
     ISetP(OpISetP),
     Lop3(OpLop3),
     Shl(OpShl),
+    I2F(OpI2F),
     Mov(OpMov),
     Sel(OpSel),
     PLop3(OpPLop3),
@@ -1198,6 +1307,16 @@ impl Instr {
         }))
     }
 
+    pub fn new_i2f(dst: Dst, src: Src) -> Instr {
+        Instr::new(Op::I2F(OpI2F {
+            dst: dst,
+            src: src,
+            dst_type: FloatType::F32,
+            src_type: IntType::I32,
+            rnd_mode: FRndMode::NearestEven,
+        }))
+    }
+
     pub fn new_isetp(
         dst: Dst,
         cmp_type: IntCmpType,
@@ -1360,7 +1479,7 @@ impl Instr {
             | Op::PLop3(_)
             | Op::ISetP(_)
             | Op::Shl(_) => Some(6),
-            Op::Mov(_) => Some(15),
+            Op::I2F(_) | Op::Mov(_) => Some(15),
             Op::Sel(_) => Some(15),
             Op::S2R(_) => None,
             Op::ALd(_) => None,