Commit Graph

7 Commits

Author SHA1 Message Date
Nadav Rotem 7b7585d153 Revert 179071 because it is not the right way to support non standard new/new[] operators.
llvm-svn: 179084
2013-04-09 04:43:46 +00:00
Nadav Rotem 9dd90ac5b4 c++ new operators are not malloc-like functions because they do not return uninitialized memory.
Users may overide new-operators and implement any function that they like.

llvm-svn: 179071
2013-04-08 23:40:47 +00:00
Nuno Lopes fa0dffccee teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users.
This means we can do cheap DSE for heap memory.
Nothing is done if the pointer excapes or has a load.

The churn in the tests is mostly due to objectsize, since we want to make sure we
don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0)

llvm-svn: 159876
2012-07-06 23:09:25 +00:00
Nuno Lopes 9ac4661afa make instcombine produce calls to llvm.donothing instead of a random intrinsic
llvm-svn: 159384
2012-06-28 22:31:24 +00:00
Nuno Lopes 07594cba7c improve optimization of invoke instructions:
- simplifycfg:  invoke undef/null -> unreachable
 - instcombine:  invoke new  -> invoke expect(0, 0)  (an arbitrary NOOP intrinsic;  only done if the allocated memory is unused, of course)
 - verifier:  allow invoke of intrinsics  (to make the previous step work)

llvm-svn: 159146
2012-06-25 17:11:47 +00:00
Nuno Lopes dc6085e52d Add support for invoke to the MemoryBuiltin analysid.
Update comments accordingly.

Make instcombine remove useless invokes to C++'s 'new' allocation function (test attached).

llvm-svn: 158937
2012-06-21 21:25:05 +00:00
Nuno Lopes a6aa3d3b5f hopefully fix the buildbots: some tests have wrong definitions of malloc and were crashing this code on 64 bits machines
llvm-svn: 158923
2012-06-21 16:47:58 +00:00