[BFI] Fix missed BFI updates in MachineSink.

Summary:
This prevents BFI queries on new blocks (from
MachineSinking::GetAllSortedSuccessors) and fixes a bunch of assert failures
under -check-bfi-unknown-block-queries=true.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74511

diff --git a/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h b/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
index 2a826d0..0f8d69e 100644 (file)
--- a/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
@@ -66,6 +66,8 @@ public:
 
   bool isIrrLoopHeader(const MachineBasicBlock *MBB);
 
+  void setBlockFreq(const MachineBasicBlock *MBB, uint64_t Freq);
+
   const MachineFunction *getFunction() const;
   const MachineBranchProbabilityInfo *getMBPI() const;
   void view(const Twine &Name, bool isSimple = true) const;

diff --git a/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp b/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp
index d8ea3e0..1168b01 100644 (file)
--- a/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp
+++ b/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp
@@ -247,6 +247,12 @@ MachineBlockFrequencyInfo::isIrrLoopHeader(const MachineBasicBlock *MBB) {
   return MBFI->isIrrLoopHeader(MBB);
 }
 
+void MachineBlockFrequencyInfo::setBlockFreq(const MachineBasicBlock *MBB,
+                                             uint64_t Freq) {
+  assert(MBFI && "Expected analysis to be available");
+  MBFI->setBlockFreq(MBB, Freq);
+}
+
 const MachineFunction *MachineBlockFrequencyInfo::getFunction() const {
   return MBFI ? MBFI->getFunction() : nullptr;
 }

diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index ab9a713..ac342ba 100644 (file)
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -91,7 +91,7 @@ namespace {
     MachineDominatorTree *DT;      // Machine dominator tree
     MachinePostDominatorTree *PDT; // Machine post dominator tree
     MachineLoopInfo *LI;
-    const MachineBlockFrequencyInfo *MBFI;
+    MachineBlockFrequencyInfo *MBFI;
     const MachineBranchProbabilityInfo *MBPI;
     AliasAnalysis *AA;
 
@@ -351,6 +351,11 @@ bool MachineSinking::runOnMachineFunction(MachineFunction &MF) {
                           << printMBBReference(*Pair.first) << " -- "
                           << printMBBReference(*NewSucc) << " -- "
                           << printMBBReference(*Pair.second) << '\n');
+        if (MBFI) {
+          auto NewSuccFreq = MBFI->getBlockFreq(Pair.first) *
+                             MBPI->getEdgeProbability(Pair.first, NewSucc);
+          MBFI->setBlockFreq(NewSucc, NewSuccFreq.getFrequency());
+        }
         MadeChange = true;
         ++NumSplit;
       } else

diff --git a/llvm/test/CodeGen/X86/machine-sink.ll b/llvm/test/CodeGen/X86/machine-sink.ll
index 8fc8984..7e2b113 100644 (file)
--- a/llvm/test/CodeGen/X86/machine-sink.ll
+++ b/llvm/test/CodeGen/X86/machine-sink.ll
@@ -1,4 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-pc-linux -check-bfi-unknown-block-queries=true | FileCheck %s
 
 ; Checks if movl $1 is sinked to critical edge.
 ; CHECK-NOT: movl $1