Commit Graph

8 Commits

Author SHA1 Message Date
Cameron Zwarich
bf5c9cd119 Roll r127459 back in:
Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

llvm-svn: 127498
2011-03-11 21:52:04 +00:00
Daniel Dunbar
a02706c889 Revert r127459, "Optimize trivial branches in CodeGenPrepare, which often get
created from the", it broke some GCC test suite tests.

llvm-svn: 127477
2011-03-11 19:30:30 +00:00
Cameron Zwarich
9ed726c151 Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

llvm-svn: 127459
2011-03-11 04:54:27 +00:00
Chris Lattner
55c2150f36 temporarily revert r123526. While working on a follow-on patch I
realize that ConstantFoldTerminator doesn't preserve dominfo.

llvm-svn: 123527
2011-01-15 07:51:19 +00:00
Chris Lattner
68a47147ba fix rdar://8785296 - -fcatch-undefined-behavior generates inefficient code
The basic issue is that isel (very reasonably!) expects conditional branches
to be folded, so CGP leaving around a bunch dead computation feeding
conditional branches isn't such a good idea.  Just fold branches on constants
into unconditional branches.

llvm-svn: 123526
2011-01-15 07:36:13 +00:00
Chris Lattner
d4eaf6eba8 Now that instruction optzns can update the iterator as they go, we can
have objectsize folding recursively simplify away their result when it
folds.  It is important to catch this here, because otherwise we won't
eliminate the cross-block values at isel and other times.

llvm-svn: 123524
2011-01-15 07:25:29 +00:00
Chris Lattner
0965f3f76d revert r122164, I'm going to go with a different approach.
llvm-svn: 122168
2010-12-19 04:23:03 +00:00
Chris Lattner
14a3e26146 first step to fixing PR8642: don't fold away empty basic blocks
which have trapping constant exprs in them due to PHI nodes.
Eliminating them can cause the constant expr to be evalutated
on new paths if the input edges are critical.

llvm-svn: 122164
2010-12-19 03:02:34 +00:00