---

yaml
---
r: 273870
b: refs/heads/beta
c: 02cb1d4
h: refs/heads/master

Author: Aatch

[refs]

@@ -23,7 +23,7 @@ refs/tags/0.9: 36870b185fc5f5486636d4515f0e22677493f225
 refs/tags/0.10: ac33f2b15782272ae348dbd7b14b8257b2148b5a
 refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
-refs/heads/beta: c70bc3a5daa2ce46aad7c230004ade7a404c12f1
+refs/heads/beta: 02cb1d4ef1e187494f7f089e114515dc74fabd10
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: e06d2ad9fcd5027bcaac5b08fc9aa39a49d0ecd3
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f

branches/beta/src/librustc_trans/basic_block.rs

@@ -49,4 +49,10 @@ impl BasicBlock {
             _ => None
         }
     }
+
+    pub fn delete(self) {
+        unsafe {
+            llvm::LLVMDeleteBasicBlock(self.0);
+        }
+    }
 }

branches/beta/src/librustc_trans/mir/mod.rs

@@ -19,6 +19,8 @@ use common::{self, Block, BlockAndBuilder, FunctionContext};
 use std::ops::Deref;
 use std::rc::Rc;
 
+use trans::basic_block::BasicBlock;
+
 use rustc_data_structures::bitvec::BitVector;
 
 use self::lvalue::{LvalueRef, get_dataptr, get_meta};
@@ -170,19 +172,20 @@ pub fn trans_mir<'blk, 'tcx: 'blk>(fcx: &'blk FunctionContext<'blk, 'tcx>) {
         mircx.trans_block(bb);
     }
 
-    // Add unreachable instructions at the end of unreachable blocks
-    // so they're actually terminated.
-    // TODO: Remove the blocks from the function
+    // Remove blocks that haven't been visited, or have no
+    // predecessors.
     for &bb in &mir_blocks {
+        let block = mircx.blocks[bb.index()];
+        let block = BasicBlock(block.llbb);
+        // Unreachable block
         if !visited.contains(bb.index()) {
-            mircx.blocks[bb.index()].build().unreachable();
+            block.delete();
+        } else if block.pred_iter().count() == 0 {
+            block.delete();
         }
     }
 
-
     fcx.cleanup();
-
-    debug!("trans_mir: {:?}", ::trans::value::Value(fcx.llfn));
 }
 
 /// Produce, for each argument, a `ValueRef` pointing at the