commit 8426d1342d82b365f4997c3d222c349fe7fba2ac
author Matthias Braun <matze@braunis.de> Wed Aug 23 03:17:59 2017 +0000
committer Matthias Braun <matze@braunis.de> Wed Aug 23 03:17:59 2017 +0000
tree 97ebae8104e0c0a140bc498aa1e61a6631db5b6a
parent 498117bf11d8e7be5770f5f16da398a5e372c4be

Add test case for r311511

This also changes the TailDuplicator to be configured explicitely
pre/post regalloc rather than relying on the isSSA() flag. This was
necessary to have `llc -run-pass` work reliably.

llvm-svn: 311520

llvm/lib/CodeGen/MachineBlockPlacement.cpp

diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index 6533030..c30f306 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -2729,7 +2729,8 @@
     MPDT = &getAnalysis<MachinePostDominatorTree>();
     if (MF.getFunction()->optForSize())
       TailDupSize = 1;
-    TailDup.initMF(MF, MBPI, /* LayoutMode */ true, TailDupSize);
+    bool PreRegAlloc = false;
+    TailDup.initMF(MF, PreRegAlloc, MBPI, /* LayoutMode */ true, TailDupSize);
     precomputeTriangleChains();
   }
 

llvm/lib/CodeGen/TailDuplication.cpp

diff --git a/llvm/lib/CodeGen/TailDuplication.cpp b/llvm/lib/CodeGen/TailDuplication.cpp
index 489a607..131b9a2 100644
--- a/llvm/lib/CodeGen/TailDuplication.cpp
+++ b/llvm/lib/CodeGen/TailDuplication.cpp
@@ -52,7 +52,10 @@
 
   auto MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
 
-  Duplicator.initMF(MF, MBPI, /* LayoutMode */ false);
+  // TODO: Querying isSSA() to determine pre-/post-regalloc is fragile, better
+  // split this into two passes instead.
+  bool PreRegAlloc = MF.getRegInfo().isSSA();
+  Duplicator.initMF(MF, PreRegAlloc, MBPI, /* LayoutMode */ false);
 
   bool MadeChange = false;
   while (Duplicator.tailDuplicateBlocks())

llvm/lib/CodeGen/TailDuplicator.cpp

diff --git a/llvm/lib/CodeGen/TailDuplicator.cpp b/llvm/lib/CodeGen/TailDuplicator.cpp
index 0f22040..bd3a20f 100644
--- a/llvm/lib/CodeGen/TailDuplicator.cpp
+++ b/llvm/lib/CodeGen/TailDuplicator.cpp
@@ -75,7 +75,7 @@
 static cl::opt<unsigned> TailDupLimit("tail-dup-limit", cl::init(~0U),
                                       cl::Hidden);
 
-void TailDuplicator::initMF(MachineFunction &MFin,
+void TailDuplicator::initMF(MachineFunction &MFin, bool PreRegAlloc,
                             const MachineBranchProbabilityInfo *MBPIin,
                             bool LayoutModeIn, unsigned TailDupSizeIn) {
   MF = &MFin;
@@ -89,7 +89,7 @@
   assert(MBPI != nullptr && "Machine Branch Probability Info required");
 
   LayoutMode = LayoutModeIn;
-  PreRegAlloc = MRI->isSSA();
+  this->PreRegAlloc = PreRegAlloc;
 }
 
 static void VerifyPHIs(MachineFunction &MF, bool CheckExtra) {