This reverts r365061 and r365062 (test update)

Revision r365061 changed a skip of debug instructions for a skip
of meta instructions. This is not safe, as IMPLICIT_DEF is classed
as a meta instruction.

llvm-svn: 365198

2 files changed, 11 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index c3e9c185be9..6f69a0f0bd3 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -1384,7 +1384,7 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI,
   // Try searching forwards from Before, looking for reads or defs.
   const_iterator I(Before);
   for (; I != end() && N > 0; ++I) {
-    if (I->isDebugInstr())
+    if (I->isMetaInstruction())
       continue;
 
     --N;
@@ -1423,7 +1423,7 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI,
     do {
       --I;
 
-      if (I->isDebugInstr())
+      if (I->isMetaInstruction())
         continue;
 
       --N;
@@ -1456,6 +1456,11 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI,
     } while (I != begin() && N > 0);
   }
 
+  // Check for the edge condition where the only instructions between I and
+  // begin() are meta instructions.
+  if (I != begin() && std::prev(I)->isMetaInstruction()) 
+    I = skipMetaInstructionsBackward(std::prev(I), begin());
+
   // Did we get to the start of the block?
   if (I == begin()) {
     // If so, the register's state is definitely defined by the live-in state.
diff --git a/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp b/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
index c307700e70b..3dcc1015dc7 100644
--- a/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
+++ b/llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp
@@ -408,7 +408,7 @@ void X86AvoidSFBPass::buildCopy(MachineInstr *LoadInst, unsigned NLoadOpcode,
   // If the load and store are consecutive, use the loadInst location to
   // reduce register pressure.
   MachineInstr *StInst = StoreInst;
-  auto PrevInstrIt = skipMetaInstructionsBackward(
+  auto PrevInstrIt = skipDebugInstructionsBackward(
       std::prev(MachineBasicBlock::instr_iterator(StoreInst)),
       MBB->instr_begin());
   if (PrevInstrIt.getNodePtr() == LoadInst)
@@ -496,7 +496,7 @@ void X86AvoidSFBPass::buildCopies(int Size, MachineInstr *LoadInst,
 static void updateKillStatus(MachineInstr *LoadInst, MachineInstr *StoreInst) {
   MachineOperand &LoadBase = getBaseOperand(LoadInst);
   MachineOperand &StoreBase = getBaseOperand(StoreInst);
-  auto StorePrevNonMetaInstr = skipMetaInstructionsBackward(
+  auto StorePrevNonDbgInstr = skipDebugInstructionsBackward(
           std::prev(MachineBasicBlock::instr_iterator(StoreInst)),
           LoadInst->getParent()->instr_begin()).getNodePtr();
   if (LoadBase.isReg()) {
@@ -505,13 +505,13 @@ static void updateKillStatus(MachineInstr *LoadInst, MachineInstr *StoreInst) {
     // then the partial copies were also created in
     // a consecutive order to reduce register pressure,
     // and the location of the last load is before the last store.
-    if (StorePrevNonMetaInstr == LoadInst)
+    if (StorePrevNonDbgInstr == LoadInst)
       LastLoad = LoadInst->getPrevNode()->getPrevNode();
     getBaseOperand(LastLoad).setIsKill(LoadBase.isKill());
   }
   if (StoreBase.isReg()) {
     MachineInstr *StInst = StoreInst;
-    if (StorePrevNonMetaInstr == LoadInst)
+    if (StorePrevNonDbgInstr == LoadInst)
       StInst = LoadInst;
     getBaseOperand(StInst->getPrevNode()).setIsKill(StoreBase.isKill());
   }