nak/sm50: sprinkle OpAnnotate in optimization passes

Not only do we want to know where an Op originated from, but also how it got
transformed along the way if possible. Preferably all the way to the final
machine code emitted.

This commit inserts OpAnnotates in some of the optimization passes when
map_instr() or Instr::new_boxed is used.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27158>

src/nouveau/compiler/nak/assign_regs.rs

@@ -1,6 +1,7 @@
 // Copyright © 2022 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
+use crate::api::{GetDebugFlags, DEBUG};
 use crate::bitset::BitSet;
 use crate::ir::*;
 use crate::liveness::{BlockLiveness, Liveness, SimpleLiveness};
@@ -1138,6 +1139,11 @@ impl AssignRegsBlock {
             );
 
             if !pcopy.is_empty() {
+                if DEBUG.annotate() {
+                    instrs.push(Instr::new_boxed(OpAnnotate {
+                        annotation: "generated by assign_regs".into(),
+                    }));
+                }
                 instrs.push(Instr::new_boxed(pcopy));
             }
 
@@ -1170,6 +1176,11 @@ impl AssignRegsBlock {
             pcopy.push(dst.into(), src.into());
         }
 
+        if DEBUG.annotate() {
+            b.instrs.push(Instr::new_boxed(OpAnnotate {
+                annotation: "generated by assign_regs".into(),
+            }));
+        }
         if b.branch().is_some() {
             b.instrs.insert(b.instrs.len() - 1, Instr::new_boxed(pcopy));
         } else {

src/nouveau/compiler/nak/legalize.rs

@@ -1,6 +1,7 @@
 // Copyright © 2022 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
+use crate::api::{GetDebugFlags, DEBUG};
 use crate::ir::*;
 use crate::liveness::{BlockLiveness, Liveness, SimpleLiveness};
 
@@ -54,6 +55,12 @@ fn copy_alu_src(b: &mut impl SSABuilder, src: &mut Src, src_type: SrcType) {
         _ => panic!("Unknown source type"),
     };
 
+    if DEBUG.annotate() {
+        b.push_instr(Instr::new_boxed(OpAnnotate {
+            annotation: "copy generated by legalizer".into(),
+        }));
+    }
+
     if val.comps() == 1 {
         b.copy_to(val.into(), src.src_ref.into());
     } else {

src/nouveau/compiler/nak/lower_copy_swap.rs

@@ -1,7 +1,10 @@
 // Copyright © 2022 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
-use crate::ir::*;
+use crate::{
+    api::{GetDebugFlags, DEBUG},
+    ir::*,
+};
 
 use std::cmp::max;
 
@@ -179,12 +182,24 @@ impl LowerCopySwap {
                 Op::Copy(copy) => {
                     debug_assert!(instr.pred.is_true());
                     let mut b = InstrBuilder::new(sm);
+                    if DEBUG.annotate() {
+                        b.push_instr(Instr::new_boxed(OpAnnotate {
+                            annotation: "copy lowered by lower_copy_swap"
+                                .into(),
+                        }));
+                    }
                     self.lower_copy(&mut b, copy);
                     b.as_mapped_instrs()
                 }
                 Op::Swap(swap) => {
                     debug_assert!(instr.pred.is_true());
                     let mut b = InstrBuilder::new(sm);
+                    if DEBUG.annotate() {
+                        b.push_instr(Instr::new_boxed(OpAnnotate {
+                            annotation: "swap lowered by lower_copy_swap"
+                                .into(),
+                        }));
+                    }
                     self.lower_swap(&mut b, swap);
                     b.as_mapped_instrs()
                 }

src/nouveau/compiler/nak/lower_par_copies.rs

@@ -1,7 +1,10 @@
 // Copyright © 2022 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
-use crate::ir::*;
+use crate::{
+    api::{GetDebugFlags, DEBUG},
+    ir::*,
+};
 
 use std::collections::HashMap;
 
@@ -254,7 +257,30 @@ impl Shader {
             match instr.op {
                 Op::ParCopy(pc) => {
                     assert!(instr.pred.is_true());
-                    lower_par_copy(pc, sm)
+                    let mut instrs = vec![];
+                    if DEBUG.annotate() {
+                        instrs.push(Instr::new_boxed(OpAnnotate {
+                            annotation: "par_copy lowered by lower_par_copy"
+                                .into(),
+                        }));
+                    }
+                    match lower_par_copy(pc, sm) {
+                        MappedInstrs::None => {
+                            if let Some(instr) = instrs.pop() {
+                                MappedInstrs::One(instr)
+                            } else {
+                                MappedInstrs::None
+                            }
+                        }
+                        MappedInstrs::One(i) => {
+                            instrs.push(i);
+                            MappedInstrs::Many(instrs)
+                        }
+                        MappedInstrs::Many(i) => {
+                            instrs.extend(i);
+                            MappedInstrs::Many(instrs)
+                        }
+                    }
                 }
                 _ => MappedInstrs::One(instr),
             }

src/nouveau/compiler/nak/opt_bar_prop.rs

@@ -1,6 +1,7 @@
 // Copyright © 2023 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
+use crate::api::{GetDebugFlags, DEBUG};
 use crate::bitset::BitSet;
 use crate::ir::*;
 
@@ -236,7 +237,16 @@ impl BarPropPass {
                     if bmovs.is_empty() {
                         MappedInstrs::One(instr)
                     } else {
-                        bmovs.insert(0, instr);
+                        if DEBUG.annotate() {
+                            bmovs.insert(
+                                0,
+                                Instr::new_boxed(OpAnnotate {
+                                    annotation: "generated by opt_bar_prop"
+                                        .into(),
+                                }),
+                            );
+                        }
+                        bmovs.insert(1, instr);
                         MappedInstrs::Many(bmovs)
                     }
                 }

src/nouveau/compiler/nak/opt_dce.rs

@@ -1,7 +1,10 @@
 // Copyright © 2022 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
-use crate::ir::*;
+use crate::{
+    api::{GetDebugFlags, DEBUG},
+    ir::*,
+};
 
 use std::collections::HashSet;
 
@@ -143,7 +146,13 @@ impl DeadCodePass {
         if is_live {
             MappedInstrs::One(instr)
         } else {
-            MappedInstrs::None
+            if DEBUG.annotate() {
+                MappedInstrs::One(Instr::new_boxed(OpAnnotate {
+                    annotation: "killed by dce".into(),
+                }))
+            } else {
+                MappedInstrs::None
+            }
         }
     }
 

src/nouveau/compiler/nak/opt_out.rs

@@ -1,7 +1,10 @@
 // Copyright © 2023 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
-use crate::ir::*;
+use crate::{
+    api::{GetDebugFlags, DEBUG},
+    ir::*,
+};
 
 fn try_combine_outs(emit: &mut Instr, cut: &Instr) -> bool {
     let Op::Out(emit) = &mut emit.op else {
@@ -46,6 +49,11 @@ impl Shader {
                 for instr in b.instrs.drain(..) {
                     if let Some(prev) = instrs.last_mut() {
                         if try_combine_outs(prev, &instr) {
+                            if DEBUG.annotate() {
+                                instrs.push(Instr::new_boxed(OpAnnotate {
+                                    annotation: "combined by opt_out".into(),
+                                }));
+                            }
                             continue;
                         }
                     }

src/nouveau/compiler/nak/spill_values.rs

@@ -666,6 +666,15 @@ fn spill_values<S: Spill>(
                             let src_ssa = &src.src_ref.as_ssa().unwrap()[0];
                             if spills.contains(dst_ssa) {
                                 if b.s.insert(*src_ssa) {
+                                    if DEBUG.annotate() {
+                                        instrs.push(Instr::new_boxed(
+                                            OpAnnotate {
+                                                annotation:
+                                                    "generated by spill_values"
+                                                        .into(),
+                                            },
+                                        ));
+                                    }
                                     instrs.push(spill.spill(*src_ssa));
                                 }
                                 b.s.insert(*dst_ssa);
@@ -710,11 +719,22 @@ fn spill_values<S: Spill>(
                         for ssa in spills {
                             debug_assert!(ssa.file() == file);
                             b.w.remove(&ssa);
+                            if DEBUG.annotate() {
+                                instrs.push(Instr::new_boxed(OpAnnotate {
+                                    annotation: "generated by spill_values"
+                                        .into(),
+                                }));
+                            }
                             instrs.push(spill.spill(ssa));
                             b.s.insert(ssa);
                         }
                     }
 
+                    if DEBUG.annotate() {
+                        instrs.push(Instr::new_boxed(OpAnnotate {
+                            annotation: "generated by spill_values".into(),
+                        }));
+                    }
                     instrs.append(&mut fills);
 
                     instr.for_each_ssa_use(|ssa| {

src/nouveau/compiler/nak/to_cssa.rs

@@ -1,6 +1,7 @@
 // Copyright © 2023 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
+use crate::api::{GetDebugFlags, DEBUG};
 use crate::cfg::CFG;
 use crate::ir::*;
 use crate::liveness::{BlockLiveness, Liveness, SimpleLiveness};
@@ -338,6 +339,11 @@ impl Function {
 
                         instrs.push(instr);
                         if !pcopy.is_empty() {
+                            if DEBUG.annotate() {
+                                instrs.push(Instr::new_boxed(OpAnnotate {
+                                    annotation: "generated by to_cssa".into(),
+                                }));
+                            }
                             instrs.push(Instr::new_boxed(pcopy));
                         }
                     }
@@ -362,6 +368,12 @@ impl Function {
                                 // and are not considered part of the parallel
                                 // copy.
                                 let tmp = self.ssa_alloc.alloc(file);
+                                if DEBUG.annotate() {
+                                    instrs.push(Instr::new_boxed(OpAnnotate {
+                                        annotation: "generated by to_cssa"
+                                            .into(),
+                                    }));
+                                }
                                 instrs.push(Instr::new_boxed(OpCopy {
                                     dst: tmp.into(),
                                     src: *src,
@@ -371,6 +383,11 @@ impl Function {
                         }
 
                         if !pcopy.is_empty() {
+                            if DEBUG.annotate() {
+                                instrs.push(Instr::new_boxed(OpAnnotate {
+                                    annotation: "generated by to_cssa".into(),
+                                }));
+                            }
                             instrs.push(Instr::new_boxed(pcopy));
                         }
                         instrs.push(instr);