[PATCH] D129634: [X86] Fix updating LiveVariables in convertToThreeAddress

[Jay Foad via Phabricator via llvm-commits]

foad created this revision.
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Fix all instances of:

- Bad machine code: Kill missing from LiveVariables ***

in the X86 CodeGen tests with D129213 <https://reviews.llvm.org/D129213> applied, which adds verification
of LiveIntervals after the TwoAddressInstruction pass runs.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D129634

Files:
  llvm/lib/Target/X86/X86InstrInfo.cpp


Index: llvm/lib/Target/X86/X86InstrInfo.cpp
===================================================================
--- llvm/lib/Target/X86/X86InstrInfo.cpp
+++ llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -1249,6 +1249,8 @@
   if (LV) {
     // Update live variables.
     LV->getVarInfo(InRegLEA).Kills.push_back(NewMI);
+    if (InRegLEA2)
+      LV->getVarInfo(InRegLEA2).Kills.push_back(NewMI);
     LV->getVarInfo(OutRegLEA).Kills.push_back(ExtMI);
     if (IsKill)
       LV->replaceKillInstruction(Src, MI, *InsMI);
@@ -1337,6 +1339,7 @@
   bool Is64Bit = Subtarget.is64Bit();
 
   bool Is8BitOp = false;
+  unsigned NumRegOperands = 2;
   unsigned MIOpc = MI.getOpcode();
   switch (MIOpc) {
   default: llvm_unreachable("Unreachable!");
@@ -1384,7 +1387,8 @@
     if (ImplicitOp.getReg() != 0)
       MIB.add(ImplicitOp);
     NewMI = MIB;
-
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::SHL8ri:
@@ -1416,6 +1420,8 @@
       MIB.add(ImplicitOp);
 
     NewMI = addOffset(MIB, 1);
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::DEC64r:
@@ -1437,7 +1443,8 @@
       MIB.add(ImplicitOp);
 
     NewMI = addOffset(MIB, -1);
-
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::DEC8r:
@@ -1485,8 +1492,13 @@
       MIB.add(ImplicitOp2);
 
     NewMI = addRegReg(MIB, SrcReg, isKill, SrcReg2, isKill2);
-    if (LV && Src2.isKill())
-      LV->replaceKillInstruction(SrcReg2, MI, *NewMI);
+    if (LV) {
+      if (SrcReg2 != Src2.getReg())
+        LV->getVarInfo(SrcReg2).Kills.push_back(NewMI);
+      if (SrcReg != SrcReg2 && SrcReg != Src.getReg())
+        LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
+    }
+    NumRegOperands = 3;
     break;
   }
   case X86::ADD8rr:
@@ -1525,6 +1537,8 @@
       MIB.add(ImplicitOp);
 
     NewMI = addOffset(MIB, MI.getOperand(2));
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::ADD8ri:
@@ -1729,6 +1743,7 @@
               .add(MI.getOperand(2))
               .add(Src)
               .add(MI.getOperand(3));
+    NumRegOperands = 4;
     break;
   }
   }
@@ -1736,10 +1751,11 @@
   if (!NewMI) return nullptr;
 
   if (LV) {  // Update live variables
-    if (Src.isKill())
-      LV->replaceKillInstruction(Src.getReg(), MI, *NewMI);
-    if (Dest.isDead())
-      LV->replaceKillInstruction(Dest.getReg(), MI, *NewMI);
+    for (unsigned I = 0; I < NumRegOperands; ++I) {
+      MachineOperand &Op = MI.getOperand(I);
+      if (Op.isDead() || Op.isKill())
+        LV->replaceKillInstruction(Op.getReg(), MI, *NewMI);
+    }
   }
 
   MachineBasicBlock &MBB = *MI.getParent();


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