improve "cannot yet select" errors a trivial amount: now

[oota-llvm.git] / lib / CodeGen / MachineVerifier.cpp

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 2b1c7263b7b12eeba6f2426d82c3f2991aa8848a..d5dda48cebdb2f96c66006580cff00ab04a02b8f 100644 (file)
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -380,11 +380,13 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
   const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
 
   // Count the number of landing pad successors.
-  unsigned LandingPadSuccs = 0;
+  SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
   for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
-       E = MBB->succ_end(); I != E; ++I)
-    LandingPadSuccs += (*I)->isLandingPad();
-  if (LandingPadSuccs > 1)
+       E = MBB->succ_end(); I != E; ++I) {
+    if ((*I)->isLandingPad())
+      LandingPadSuccs.insert(*I);
+  }
+  if (LandingPadSuccs.size() > 1)
     report("MBB has more than one landing pad successor", MBB);
 
   // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
@@ -402,11 +404,11 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
         // It's possible that the block legitimately ends with a noreturn
         // call or an unreachable, in which case it won't actually fall
         // out the bottom of the function.
-      } else if (MBB->succ_size() == LandingPadSuccs) {
+      } else if (MBB->succ_size() == LandingPadSuccs.size()) {
         // It's possible that the block legitimately ends with a noreturn
         // call or an unreachable, in which case it won't actuall fall
         // out of the block.
-      } else if (MBB->succ_size() != 1+LandingPadSuccs) {
+      } else if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
         report("MBB exits via unconditional fall-through but doesn't have "
                "exactly one CFG successor!", MBB);
       } else if (!MBB->isSuccessor(MBBI)) {
@@ -424,7 +426,7 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
       }
     } else if (TBB && !FBB && Cond.empty()) {
       // Block unconditionally branches somewhere.
-      if (MBB->succ_size() != 1+LandingPadSuccs) {
+      if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
         report("MBB exits via unconditional branch but doesn't have "
                "exactly one CFG successor!", MBB);
       } else if (!MBB->isSuccessor(TBB)) {
@@ -587,7 +589,9 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
       return;
 
     // Check Live Variables.
-    if (MO->isUndef()) {
+    if (MI->isDebugValue()) {
+      // Liveness checks are not valid for debug values.
+    } else if (MO->isUndef()) {
       // An <undef> doesn't refer to any register, so just skip it.
     } else if (MO->isUse()) {
       regsLiveInButUnused.erase(Reg);
@@ -690,7 +694,7 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
           const LiveInterval &LI = LiveInts->getInterval(Reg);
           if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
             assert(VNI && "NULL valno is not allowed");
-            if (VNI->def != DefIdx) {
+            if (VNI->def != DefIdx && !MO->isEarlyClobber()) {
               report("Inconsistent valno->def", MO, MONum);
               *OS << "Valno " << VNI->id << " is not defined at "
                   << DefIdx << " in " << LI << '\n';
@@ -1003,11 +1007,6 @@ void MachineVerifier::verifyLiveIntervals() {
         }
       } else {
         // Non-PHI def.
-        if (!VNI->def.isDef()) {
-          report("Non-PHI def must be at a DEF slot", MF);
-          *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
-              << " in " << LI << '\n';
-        }
         const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
         if (!MI) {
           report("No instruction at def index", MF);
@@ -1017,6 +1016,32 @@ void MachineVerifier::verifyLiveIntervals() {
           report("Defining instruction does not modify register", MI);
           *OS << "Valno #" << VNI->id << " in " << LI << '\n';
         }
+
+        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;
+            }
+          }
+        }
+
+        // Early clobber defs begin at USE slots, but other defs must begin at
+        // DEF slots.
+        if (isEarlyClobber) {
+          if (!VNI->def.isUse()) {
+            report("Early clobber def must be at a USE slot", MF);
+            *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
+                << " in " << LI << '\n';
+          }
+        } else if (!VNI->def.isDef()) {
+          report("Non-PHI, non-early clobber def must be at a DEF slot", MF);
+          *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
+              << " in " << LI << '\n';
+        }
       }
     }
 
@@ -1070,10 +1095,24 @@ void MachineVerifier::verifyLiveIntervals() {
             << MBBStartIdx << '\n';
         } else if (TargetRegisterInfo::isVirtualRegister(LI.reg) &&
                    !MI->readsVirtualRegister(LI.reg)) {
-          // FIXME: Should we require a kill flag?
-          report("Instruction killing live segment doesn't read register", MI);
-          I->print(*OS);
-          *OS << " in " << LI << '\n';
+          // 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;
+            }
+          }
+
+          if (!hasDeadDef) {
+            report("Instruction killing live segment neither defines nor reads "
+                   "register", MI);
+            I->print(*OS);
+            *OS << " in " << LI << '\n';
+          }
         }
       }