commit 77a21dbad46d07404f165c5a49c815c3d9b9eedd
author Marina Yatsina <marina.yatsina@intel.com> Mon Jan 22 10:07:01 2018 +0000
committer Marina Yatsina <marina.yatsina@intel.com> Mon Jan 22 10:07:01 2018 +0000
tree 110a32953c87abd6f5e425f6d40d1c09d51f055c
parent 0bf841ac2a7039afc2a5589c0735abbc5e263ac6

Break false dependencies for POPCNT, LZCNT, TZCNT

Add POPCNT, LZCNT, TZCNT to the list of instructions that have false dependency.
Add a test to make sure BreakFalseDeps breaks the dependencies for these instructions.
Update affected tests.

This fixes bugzilla https://bugs.llvm.org/show_bug.cgi?id=33869

This is the final of multiple patches that fix this bugzilla.
Most of the patches are intended at refactoring the existent code.

Reviews of the refactoring done to enable this change:
https://reviews.llvm.org/D40330
https://reviews.llvm.org/D40331
https://reviews.llvm.org/D40332
https://reviews.llvm.org/D40333

Differential Revision: https://reviews.llvm.org/D40334

Change-Id: If95cbf1a3f5c7dccff8f1b22ecb397542147303d
llvm-svn: 323096

llvm/lib/Target/X86/X86Subtarget.cpp

diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 082a4f7..914f491 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -329,6 +329,8 @@
   HasSSEUnalignedMem = false;
   HasCmpxchg16b = false;
   UseLeaForSP = false;
+  HasPOPCNTFalseDeps = false;
+  HasLZCNTFalseDeps = false;
   HasFastVariableShuffle = false;
   HasFastPartialYMMorZMMWrite = false;
   HasFastGather = false;