[FastISel] Fix insertion of unconditional branches during FastISel

The insertion of an unconditional branch during FastISel can differ depending on
building with or without debug information. This happens because FastISel::fastEmitBranch
emits an unconditional branch depending on the size of the current basic block
without distinguishing between debug and non-debug instructions.

This patch fixes this issue by ignoring debug instructions when getting the size
of the basic block.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: ormris, aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67703

llvm-svn: 372389

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 3441071..bdee699 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -107,6 +107,13 @@ BasicBlock::instructionsWithoutDebug() {
   return make_filter_range(*this, Fn);
 }
 
+filter_iterator<BasicBlock::const_iterator,
+                std::function<bool(const Instruction &)>>::difference_type
+BasicBlock::sizeWithoutDebug() const {
+  return std::distance(instructionsWithoutDebug().begin(),
+                       instructionsWithoutDebug().end());
+}
+
 void BasicBlock::removeFromParent() {
   getParent()->getBasicBlockList().remove(getIterator());
 }