nak: Add OpBreak

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

src/nouveau/compiler/nak_encode_sm75.rs

@@ -1615,6 +1615,12 @@ impl SM75Instr {
         self.set_bit(84, op.clear);
     }
 
+    fn encode_break(&mut self, op: &OpBreak) {
+        self.set_opcode(0x942);
+        self.set_field(16..20, op.bar.idx());
+        self.set_pred_src(87..90, 90, op.cond);
+    }
+
     fn encode_bssy(
         &mut self,
         op: &OpBSSy,
@@ -1824,6 +1830,7 @@ impl SM75Instr {
             Op::Ipa(op) => si.encode_ipa(&op),
             Op::MemBar(op) => si.encode_membar(&op),
             Op::BMov(op) => si.encode_bmov(&op),
+            Op::Break(op) => si.encode_break(&op),
             Op::BSSy(op) => si.encode_bssy(&op, ip, labels),
             Op::BSync(op) => si.encode_bsync(&op),
             Op::Bra(op) => si.encode_bra(&op, ip, labels),

src/nouveau/compiler/nak_ir.rs

@@ -3515,6 +3515,21 @@ impl fmt::Display for OpBMov {
     }
 }
 
+#[repr(C)]
+#[derive(SrcsAsSlice, DstsAsSlice)]
+pub struct OpBreak {
+    pub bar: BarRef,
+
+    #[src_type(Pred)]
+    pub cond: Src,
+}
+
+impl fmt::Display for OpBreak {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "BREAK {} {}", self.cond, self.bar)
+    }
+}
+
 #[repr(C)]
 #[derive(SrcsAsSlice, DstsAsSlice)]
 pub struct OpBSSy {
@@ -4108,6 +4123,7 @@ pub enum Op {
     Ipa(OpIpa),
     MemBar(OpMemBar),
     BMov(OpBMov),
+    Break(OpBreak),
     BSSy(OpBSSy),
     BSync(OpBSync),
     Bra(OpBra),
@@ -4462,6 +4478,7 @@ impl Instr {
             | Op::AtomCas(_)
             | Op::MemBar(_)
             | Op::Kill(_)
+            | Op::Break(_)
             | Op::BSSy(_)
             | Op::BSync(_)
             | Op::Bra(_)
@@ -4541,7 +4558,7 @@ impl Instr {
             | Op::MemBar(_) => false,
 
             // Control-flow ops
-            Op::BMov(_) | Op::BSSy(_) | Op::BSync(_) => false,
+            Op::BMov(_) | Op::Break(_) | Op::BSSy(_) | Op::BSync(_) => false,
             Op::Bra(_) | Op::Exit(_) => true,
             Op::WarpSync(_) => false,
 

src/nouveau/compiler/nak_legalize.rs

@@ -260,7 +260,7 @@ fn legalize_instr(b: &mut impl SSABuilder, instr: &mut Instr) {
             copy_src_if_not_reg(b, &mut op.handle, RegFile::GPR);
         }
         Op::Ldc(_) => (), // Nothing to do
-        Op::BMov(_) | Op::BSSy(_) | Op::BSync(_) => (), // Nothing to do
+        Op::BMov(_) | Op::Break(_) | Op::BSSy(_) | Op::BSync(_) => (),
         Op::Copy(_) => (), // Nothing to do
         _ => {
             let src_types = instr.src_types();