From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Wed, 6 Jun 2012 22:34:30 +0000 (+0000)
Subject: Properly verify liveness with bundled machine instructions.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1f9c3ec831cf63f7833680c38362c1e92c251aff;p=oota-llvm.git

Properly verify liveness with bundled machine instructions.

Bundles should be treated as one atomic transaction when checking
liveness. That is how the register allocator (and VLIW targets) treats
bundles.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158116 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 37d56f9d5dc..a5ee1d59f31 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -191,9 +191,11 @@ namespace {
 
     void visitMachineFunctionBefore();
     void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
+    void visitMachineBundleBefore(const MachineInstr *MI);
     void visitMachineInstrBefore(const MachineInstr *MI);
     void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
     void visitMachineInstrAfter(const MachineInstr *MI);
+    void visitMachineBundleAfter(const MachineInstr *MI);
     void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
     void visitMachineFunctionAfter();
 
@@ -288,6 +290,8 @@ bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
   for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
        MFI!=MFE; ++MFI) {
     visitMachineBasicBlockBefore(MFI);
+    // Keep track of the current bundle header.
+    const MachineInstr *CurBundle = 0;
     for (MachineBasicBlock::const_instr_iterator MBBI = MFI->instr_begin(),
            MBBE = MFI->instr_end(); MBBI != MBBE; ++MBBI) {
       if (MBBI->getParent() != MFI) {
@@ -295,15 +299,21 @@ bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
         *OS << "Instruction: " << *MBBI;
         continue;
       }
-      // Skip BUNDLE instruction for now. FIXME: We should add code to verify
-      // the BUNDLE's specifically.
-      if (MBBI->isBundle())
-        continue;
+      // Is this a bundle header?
+      if (!MBBI->isInsideBundle()) {
+        if (CurBundle)
+          visitMachineBundleAfter(CurBundle);
+        CurBundle = MBBI;
+        visitMachineBundleBefore(CurBundle);
+      } else if (!CurBundle)
+        report("No bundle header", MBBI);
       visitMachineInstrBefore(MBBI);
       for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
         visitMachineOperand(&MBBI->getOperand(I), I);
       visitMachineInstrAfter(MBBI);
     }
+    if (CurBundle)
+      visitMachineBundleAfter(CurBundle);
     visitMachineBasicBlockAfter(MFI);
   }
   visitMachineFunctionAfter();
@@ -575,6 +585,19 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
     lastIndex = Indexes->getMBBStartIdx(MBB);
 }
 
+// This function gets called for all bundle headers, including normal
+// stand-alone unbundled instructions.
+void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
+  if (Indexes && Indexes->hasIndex(MI)) {
+    SlotIndex idx = Indexes->getInstructionIndex(MI);
+    if (!(idx > lastIndex)) {
+      report("Instruction index out of order", MI);
+      *OS << "Last instruction was at " << lastIndex << '\n';
+    }
+    lastIndex = idx;
+  }
+}
+
 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
   const MCInstrDesc &MCID = MI->getDesc();
   if (MI->getNumOperands() < MCID.getNumOperands()) {
@@ -865,6 +888,13 @@ void MachineVerifier::checkLiveness(const MachineOperand *MO, unsigned MONum) {
 }
 
 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
+}
+
+// This function gets called after visiting all instructions in a bundle. The
+// argument points to the bundle header.
+// Normal stand-alone instructions are also considered 'bundles', and this
+// function is called for all of them.
+void MachineVerifier::visitMachineBundleAfter(const MachineInstr *MI) {
   BBInfo &MInfo = MBBInfoMap[MI->getParent()];
   set_union(MInfo.regsKilled, regsKilled);
   set_subtract(regsLive, regsKilled); regsKilled.clear();
@@ -878,15 +908,6 @@ void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
   }
   set_subtract(regsLive, regsDead);   regsDead.clear();
   set_union(regsLive, regsDefined);   regsDefined.clear();
-
-  if (Indexes && Indexes->hasIndex(MI)) {
-    SlotIndex idx = Indexes->getInstructionIndex(MI);
-    if (!(idx > lastIndex)) {
-      report("Instruction index out of order", MI);
-      *OS << "Last instruction was at " << lastIndex << '\n';
-    }
-    lastIndex = idx;
-  }
 }
 
 void