Update machine code verifier.

After the SlotIndex slot names were updated, it is possible to apply
stricter checks to live intervals.

Also treat bundles as bags of operands when checking live intervals.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151531 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 91 insertions, 35 deletions

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 065f2527ca..c0df1b19a2 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -588,12 +588,15 @@ void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
   }
 
   // Debug values must not have a slot index.
-  // Other instructions must have one.
+  // Other instructions must have one, unless they are inside a bundle.
   if (LiveInts) {
     bool mapped = !LiveInts->isNotInMIMap(MI);
     if (MI->isDebugValue()) {
       if (mapped)
         report("Debug instruction has a slot index", MI);
+    } else if (MI->isInsideBundle()) {
+      if (mapped)
+        report("Instruction inside bundle has a slot index", MI);
     } else {
       if (!mapped)
         report("Missing slot index", MI);
@@ -1086,26 +1089,35 @@ void MachineVerifier::verifyLiveIntervals() {
         }
       } else {
         // Non-PHI def.
-        const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
+        MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
         if (!MI) {
           report("No instruction at def index", MF);
           *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
               << " in " << LI << '\n';
-        } else if (!MI->modifiesRegister(LI.reg, TRI)) {
-          report("Defining instruction does not modify register", MI);
-          *OS << "Valno #" << VNI->id << " in " << LI << '\n';
+          continue;
         }
 
+        bool hasDef = false;
         bool isEarlyClobber = false;
-        if (MI) {
-          for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
-               MOE = MI->operands_end(); MOI != MOE; ++MOI) {
-            if (MOI->isReg() && MOI->getReg() == LI.reg && MOI->isDef() &&
-                MOI->isEarlyClobber()) {
-              isEarlyClobber = true;
-              break;
-            }
+        for (MIOperands MOI(MI, true); MOI.isValid(); ++MOI) {
+          if (!MOI->isReg() || !MOI->isDef())
+            continue;
+          if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
+            if (MOI->getReg() != LI.reg)
+              continue;
+          } else {
+            if (!TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) ||
+                !TRI->regsOverlap(LI.reg, MOI->getReg()))
+              continue;
           }
+          hasDef = true;
+          if (MOI->isEarlyClobber())
+            isEarlyClobber = true;
+        }
+
+        if (!hasDef) {
+          report("Defining instruction does not modify register", MI);
+          *OS << "Valno #" << VNI->id << " in " << LI << '\n';
         }
 
         // Early clobber defs begin at USE slots, but other defs must begin at
@@ -1164,32 +1176,76 @@ void MachineVerifier::verifyLiveIntervals() {
         *OS << " in " << LI << '\n';
         continue;
       }
-      if (I->end != LiveInts->getMBBEndIdx(EndMBB)) {
-        // The live segment is ending inside EndMBB
-        const MachineInstr *MI =
-                        LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
-        if (!MI) {
-          report("Live segment doesn't end at a valid instruction", EndMBB);
+
+      // No more checks for live-out segments.
+      if (I->end == LiveInts->getMBBEndIdx(EndMBB))
+        continue;
+
+      // The live segment is ending inside EndMBB
+      MachineInstr *MI =
+        LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
+      if (!MI) {
+        report("Live segment doesn't end at a valid instruction", EndMBB);
         I->print(*OS);
         *OS << " in " << LI << '\n' << "Basic block starts at "
-            << MBBStartIdx << '\n';
-        } else if (TargetRegisterInfo::isVirtualRegister(LI.reg) &&
-                   !MI->readsVirtualRegister(LI.reg)) {
-          // A live range can end with either a redefinition, a kill flag on a
-          // use, or a dead flag on a def.
-          // FIXME: Should we check for each of these?
-          bool hasDeadDef = false;
-          for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
-               MOE = MI->operands_end(); MOI != MOE; ++MOI) {
-            if (MOI->isReg() && MOI->getReg() == LI.reg && MOI->isDef() && MOI->isDead()) {
-              hasDeadDef = true;
-              break;
-            }
-          }
+          << MBBStartIdx << '\n';
+        continue;
+      }
+
+      // The block slot must refer to a basic block boundary.
+      if (I->end.isBlock()) {
+        report("Live segment ends at B slot of an instruction", MI);
+        I->print(*OS);
+        *OS << " in " << LI << '\n';
+      }
+
+      if (I->end.isDead()) {
+        // Segment ends on the dead slot.
+        // That means there must be a dead def.
+        if (!SlotIndex::isSameInstr(I->start, I->end)) {
+          report("Live segment ending at dead slot spans instructions", MI);
+          I->print(*OS);
+          *OS << " in " << LI << '\n';
+        }
+      }
+
+      // A live segment can only end at an early-clobber slot if it is being
+      // redefined by an early-clobber def.
+      if (I->end.isEarlyClobber()) {
+        if (I+1 == E || (I+1)->start != I->end) {
+          report("Live segment ending at early clobber slot must be "
+                 "redefined by an EC def in the same instruction", MI);
+          I->print(*OS);
+          *OS << " in " << LI << '\n';
+        }
+      }
+
+      // The following checks only apply to virtual registers. Physreg liveness
+      // is too weird to check.
+      if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
+        // A live range can end with either a redefinition, a kill flag on a
+        // use, or a dead flag on a def.
+        bool hasRead = false;
+        bool hasDeadDef = false;
+        for (MIOperands MOI(MI, true); MOI.isValid(); ++MOI) {
+          if (!MOI->isReg() || MOI->getReg() != LI.reg)
+            continue;
+          if (MOI->readsReg())
+            hasRead = true;
+          if (MOI->isDef() && MOI->isDead())
+            hasDeadDef = true;
+        }
 
+        if (I->end.isDead()) {
           if (!hasDeadDef) {
-            report("Instruction killing live segment neither defines nor reads "
-                   "register", MI);
+            report("Instruction doesn't have a dead def operand", MI);
+            I->print(*OS);
+            *OS << " in " << LI << '\n';
+          }
+        } else {
+          if (!hasRead) {
+            report("Instruction ending live range doesn't read the register",
+                   MI);
             I->print(*OS);
             *OS << " in " << LI << '\n';
           }