diff options
| author | Philip Reames <listmail@philipreames.com> | 2019-02-11 23:34:33 +0000 |
|---|---|---|
| committer | Philip Reames <listmail@philipreames.com> | 2019-02-11 23:34:33 +0000 |
| commit | 5906a6591cdc3aefe6c9cd67831724cae7978471 (patch) | |
| tree | 730afc97bb0ae915da962d6ebcd554a850facb6d /llvm/lib/CodeGen/ImplicitNullChecks.cpp | |
| parent | e3cd735ea6378e5dd7765828f560ed49be845a95 (diff) | |
Be conservative about unordered accesses for the moment
Background: As described in https://reviews.llvm.org/D57601, I'm working towards separating volatile and atomic in the MMO uses for atomic instructions.
In https://reviews.llvm.org/D57593, I fixed a bug where isUnordered was returning the wrong result, but didn't account for the fact I was getting slightly ahead of myself. While both uses of isUnordered are correct (as far as I can tell), we don't have tests to demonstrate this and being aggressive gets in the way of having the removal of volatile truly be non-functional. Once D57601 lands, I will return to these call sites, revert this patch, and add the appropriate tests to show the expected behaviour.
Differential Revision: https://reviews.llvm.org/D57802
llvm-svn: 353766
Diffstat (limited to 'llvm/lib/CodeGen/ImplicitNullChecks.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/ImplicitNullChecks.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/ImplicitNullChecks.cpp b/llvm/lib/CodeGen/ImplicitNullChecks.cpp index 681103141517..75f4eef5dc1c 100644 --- a/llvm/lib/CodeGen/ImplicitNullChecks.cpp +++ b/llvm/lib/CodeGen/ImplicitNullChecks.cpp @@ -235,8 +235,11 @@ bool ImplicitNullChecks::canHandle(const MachineInstr *MI) { assert(!llvm::any_of(MI->operands(), IsRegMask) && "Calls were filtered out above!"); - auto IsUnordered = [](MachineMemOperand *MMO) { return MMO->isUnordered(); }; - return llvm::all_of(MI->memoperands(), IsUnordered); + // TODO: This should be isUnordered (see D57601) once test cases are written + // demonstrating that. + auto IsSimple = [](MachineMemOperand *MMO) { + return !MMO->isVolatile() && !MMO->isAtomic(); }; + return llvm::all_of(MI->memoperands(), IsSimple); } ImplicitNullChecks::DependenceResult |