New pass to deduplicate blocks

3 files changed, 115 insertions, 1 deletions

diff --git a/src/test/mir-opt/deduplicate_blocks.is_line_doc_comment_2.DeduplicateBlocks.diff b/src/test/mir-opt/deduplicate_blocks.is_line_doc_comment_2.DeduplicateBlocks.diff
new file mode 100644
index 00000000000..b6e4469e870
--- /dev/null
+++ b/src/test/mir-opt/deduplicate_blocks.is_line_doc_comment_2.DeduplicateBlocks.diff
@@ -0,0 +1,101 @@
+- // MIR for `is_line_doc_comment_2` before DeduplicateBlocks
++ // MIR for `is_line_doc_comment_2` after DeduplicateBlocks
+  
+  fn is_line_doc_comment_2(_1: &str) -> bool {
+      debug s => _1;                       // in scope 0 at $DIR/deduplicate_blocks.rs:2:36: 2:37
+      let mut _0: bool;                    // return place in scope 0 at $DIR/deduplicate_blocks.rs:2:48: 2:52
+      let mut _2: &[u8];                   // in scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+      let mut _3: usize;                   // in scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
+      let mut _4: bool;                    // in scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
+      let mut _5: usize;                   // in scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
+      let mut _6: bool;                    // in scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
+      scope 1 (inlined core::str::<impl str>::as_bytes) { // at $DIR/deduplicate_blocks.rs:3:11: 3:23
+          debug self => _7;                // in scope 1 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+          let mut _7: &str;                // in scope 1 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+          scope 2 {
+          }
+      }
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+          _7 = _1;                         // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:12
+-         _2 = transmute::<&str, &[u8]>(move _7) -> bb14; // scope 2 at $DIR/deduplicate_blocks.rs:3:11: 3:23
++         _2 = transmute::<&str, &[u8]>(move _7) -> bb12; // scope 2 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+                                           // mir::Constant
+                                           // + span: $DIR/deduplicate_blocks.rs:3:11: 3:23
+                                           // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(&str) -> &[u8] {std::intrinsics::transmute::<&str, &[u8]>}, val: Value(Scalar(<ZST>)) }
+      }
+  
+      bb1: {
+          switchInt((*_2)[0 of 4]) -> [47_u8: bb2, otherwise: bb5]; // scope 0 at $DIR/deduplicate_blocks.rs:4:10: 4:14
+      }
+  
+      bb2: {
+          switchInt((*_2)[1 of 4]) -> [47_u8: bb3, otherwise: bb5]; // scope 0 at $DIR/deduplicate_blocks.rs:4:16: 4:20
+      }
+  
+      bb3: {
+          switchInt((*_2)[2 of 4]) -> [47_u8: bb4, otherwise: bb5]; // scope 0 at $DIR/deduplicate_blocks.rs:4:22: 4:26
+      }
+  
+      bb4: {
+-         switchInt((*_2)[3 of 4]) -> [47_u8: bb10, otherwise: bb5]; // scope 0 at $DIR/deduplicate_blocks.rs:4:28: 4:32
++         switchInt((*_2)[3 of 4]) -> [47_u8: bb9, otherwise: bb5]; // scope 0 at $DIR/deduplicate_blocks.rs:4:28: 4:32
+      }
+  
+      bb5: {
+          _3 = Len((*_2));                 // scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
+          _4 = Ge(move _3, const 3_usize); // scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
+          switchInt(move _4) -> [false: bb9, otherwise: bb6]; // scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
+      }
+  
+      bb6: {
+          switchInt((*_2)[0 of 3]) -> [47_u8: bb7, otherwise: bb9]; // scope 0 at $DIR/deduplicate_blocks.rs:5:10: 5:14
+      }
+  
+      bb7: {
+          switchInt((*_2)[1 of 3]) -> [47_u8: bb8, otherwise: bb9]; // scope 0 at $DIR/deduplicate_blocks.rs:5:16: 5:20
+      }
+  
+      bb8: {
+-         switchInt((*_2)[2 of 3]) -> [47_u8: bb11, 33_u8: bb12, otherwise: bb9]; // scope 0 at $DIR/deduplicate_blocks.rs:5:22: 5:26
++         switchInt((*_2)[2 of 3]) -> [47_u8: bb10, 33_u8: bb10, otherwise: bb9]; // scope 0 at $DIR/deduplicate_blocks.rs:5:22: 5:26
+      }
+  
+      bb9: {
+-         _0 = const false;                // scope 0 at $DIR/deduplicate_blocks.rs:7:14: 7:19
+-         goto -> bb13;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
+-     }
+- 
+-     bb10: {
+          _0 = const false;                // scope 0 at $DIR/deduplicate_blocks.rs:4:41: 4:46
+-         goto -> bb13;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
++         goto -> bb11;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
+      }
+  
+-     bb11: {
+-         _0 = const true;                 // scope 0 at $DIR/deduplicate_blocks.rs:5:35: 5:39
+-         goto -> bb13;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
+-     }
+- 
+-     bb12: {
++     bb10: {
+          _0 = const true;                 // scope 0 at $DIR/deduplicate_blocks.rs:6:35: 6:39
+-         goto -> bb13;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
++         goto -> bb11;                    // scope 0 at $DIR/deduplicate_blocks.rs:3:5: 8:6
+      }
+  
+-     bb13: {
++     bb11: {
+          StorageDead(_2);                 // scope 0 at $DIR/deduplicate_blocks.rs:9:1: 9:2
+          return;                          // scope 0 at $DIR/deduplicate_blocks.rs:9:2: 9:2
+      }
+  
+-     bb14: {
++     bb12: {
+          _5 = Len((*_2));                 // scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
+          _6 = Ge(move _5, const 4_usize); // scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
+          switchInt(move _6) -> [false: bb5, otherwise: bb1]; // scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
+      }
+  }
+  
diff --git a/src/test/mir-opt/deduplicate_blocks.rs b/src/test/mir-opt/deduplicate_blocks.rs
new file mode 100644
index 00000000000..f8f7361dc0d
--- /dev/null
+++ b/src/test/mir-opt/deduplicate_blocks.rs
@@ -0,0 +1,13 @@
+// EMIT_MIR deduplicate_blocks.is_line_doc_comment_2.DeduplicateBlocks.diff
+pub const fn is_line_doc_comment_2(s: &str) -> bool {
+    match s.as_bytes() {
+        [b'/', b'/', b'/', b'/', ..] => false,
+        [b'/', b'/', b'/', ..] => true,
+        [b'/', b'/', b'!', ..] => true,
+        _ => false,
+    }
+}
+
+fn main() {
+    is_line_doc_comment_2("asd");
+}
diff --git a/src/test/mir-opt/inline/inline_diverging.h.Inline.diff b/src/test/mir-opt/inline/inline_diverging.h.Inline.diff
index 07994eb3c16..e945629b613 100644
--- a/src/test/mir-opt/inline/inline_diverging.h.Inline.diff
+++ b/src/test/mir-opt/inline/inline_diverging.h.Inline.diff
@@ -46,7 +46,7 @@
 +         _4 = &_2;                        // scope 1 at $DIR/inline-diverging.rs:22:5: 22:22
 +         StorageLive(_7);                 // scope 1 at $DIR/inline-diverging.rs:22:5: 22:22
 +         _7 = const ();                   // scope 1 at $DIR/inline-diverging.rs:22:5: 22:22
-+         goto -> bb1;                     // scope 5 at $DIR/inline-diverging.rs:22:5: 22:22
++         goto -> bb1;                     // scope 4 at $DIR/inline-diverging.rs:22:5: 22:22
       }
   
       bb1: {