Commit Graph

3 Commits

Author SHA1 Message Date
Clement Courbet 292291fb90 Revert r354244 "[DAGCombiner] Eliminate dead stores to stack."
Breaks some bots.

llvm-svn: 354245
2019-02-18 08:24:29 +00:00
Clement Courbet 57f34dbd3e [DAGCombiner] Eliminate dead stores to stack.
Summary:
A store to an object whose lifetime is about to end can be removed.

See PR40550 for motivation.

Reviewers: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D57541

llvm-svn: 354244
2019-02-18 07:59:01 +00:00
Yonghong Song 920df52a93 bpf: fix a bug in dag2dag optimization for loads from readonly section
The reference '&' is missing in the function parameter. If there are
back-to-back optimizations in terms of dag node list like below:
  t29: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)+12](dereferenceable), zext from i32> t3, t43, undef:i64
  t34: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)](dereferenceable), zext from i32> t3, t41, undef:i64
The bug will trigger a segfault for the added test case remove_truncate_5.ll:
  LLVMSymbolizer: error reading file: No such file or directory
  #0 0x000000000241c4d9 (llc+0x241c4d9)
  #1 0x000000000241c56a (llc+0x241c56a)
  #2 0x000000000241aa50 (llc+0x241aa50)
  ...
  #22 0x0000000000fd5edf (llc+0xfd5edf)
  #23 0x00007f0fe03bec05 __libc_start_main (/lib64/libc.so.6+0x21c05)
  #24 0x0000000000fd3e69 (llc+0xfd3e69)
  ...
  Segmentation fault

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325267
2018-02-15 17:06:45 +00:00