New structurizer: now with ∞% more φ! (#287)

EmbarkStudios · Dec 2, 2020 · e02bead · e02bead
1 parent adebc90
commit e02bead
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Showing 10 changed files with 523 additions and 13 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/rustc_codegen_spirv/Cargo.toml b/crates/rustc_codegen_spirv/Cargo.toml
@@ -28,6 +28,7 @@ use-compiled-tools = ["spirv-tools/use-compiled-tools"]
 
 [dependencies]
 bimap = "0.5"
+indexmap = "1.6.0"
 rspirv = { git = "https://github.com/gfx-rs/rspirv.git", rev = "01ca0d2e5b667a0e4ff1bc1804511e38f9a08759" }
 rustc-demangle = "0.1.18"
 spirv-tools = { version = "0.1.0", default-features = false }

diff --git a/crates/rustc_codegen_spirv/src/builder/builder_methods.rs b/crates/rustc_codegen_spirv/src/builder/builder_methods.rs
@@ -482,11 +482,6 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
         else_llbb: Self::BasicBlock,
         cases: impl ExactSizeIterator<Item = (u128, Self::BasicBlock)>,
     ) {
-        if !self.kernel_mode {
-            // TODO: Remove once structurizer is done.
-            self.zombie(else_llbb, "OpSwitch before structurizer is done");
-        }
-
         fn construct_8(self_: &Builder<'_, '_>, signed: bool, v: u128) -> Operand {
             if v > u8::MAX as u128 {
                 self_.fatal(&format!(
@@ -700,7 +695,7 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
             OverflowOp::Mul => (self.mul(lhs, rhs), fals),
         };
         self.zombie(
-            result.1.def(self),
+            result.0.def(self),
             match oop {
                 OverflowOp::Add => "checked add is not supported yet",
                 OverflowOp::Sub => "checked sub is not supported yet",

diff --git a/crates/rustc_codegen_spirv/src/link.rs b/crates/rustc_codegen_spirv/src/link.rs
@@ -408,6 +408,7 @@ fn do_link(sess: &Session, objects: &[PathBuf], rlibs: &[PathBuf], legalize: boo
         inline: legalize,
         mem2reg: legalize,
         structurize: env::var("NO_STRUCTURIZE").is_err(),
+        use_new_structurizer: env::var("OLD_STRUCTURIZER").is_err(),
     };
 
     let link_result = linker::link(sess, modules, &options);

diff --git a/crates/rustc_codegen_spirv/src/linker/mem2reg.rs b/crates/rustc_codegen_spirv/src/linker/mem2reg.rs
@@ -38,7 +38,17 @@ pub fn mem2reg(
 pub fn compute_preds(blocks: &[Block]) -> Vec<Vec<usize>> {
     let mut result = vec![vec![]; blocks.len()];
     for (source_idx, source) in blocks.iter().enumerate() {
-        for dest_id in outgoing_edges(source) {
+        let mut edges = outgoing_edges(source);
+        // HACK(eddyb) treat `OpSelectionMerge` as an edge, in case it points
+        // to an otherwise-unreachable block.
+        if let Some(before_last_idx) = source.instructions.len().checked_sub(2) {
+            if let Some(before_last) = source.instructions.get(before_last_idx) {
+                if before_last.class.opcode == Op::SelectionMerge {
+                    edges.push(before_last.operands[0].unwrap_id_ref());
+                }
+            }
+        }
+        for dest_id in edges {
             let dest_idx = blocks
                 .iter()
                 .position(|b| b.label_id().unwrap() == dest_id)

diff --git a/crates/rustc_codegen_spirv/src/linker/mod.rs b/crates/rustc_codegen_spirv/src/linker/mod.rs
@@ -7,6 +7,7 @@ mod duplicates;
 mod import_export_link;
 mod inline;
 mod mem2reg;
+mod new_structurizer;
 mod simple_passes;
 mod structurizer;
 mod zombies;
@@ -26,6 +27,7 @@ pub struct Options {
     pub inline: bool,
     pub mem2reg: bool,
     pub structurize: bool,
+    pub use_new_structurizer: bool,
 }
 
 fn id(header: &mut ModuleHeader) -> Word {
@@ -136,7 +138,11 @@ pub fn link(sess: &Session, mut inputs: Vec<Module>, opts: &Options) -> Result<M
 
     let mut output = if opts.structurize {
         let _timer = sess.timer("link_structurize");
-        structurizer::structurize(sess, output)
+        if opts.use_new_structurizer {
+            new_structurizer::structurize(output)
+        } else {
+            structurizer::structurize(sess, output)
+        }
     } else {
         output
     };