[llvm] a5a7a9d - [X86] Fix updating LiveVariables in convertToThreeAddress

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2022-08-01T13:45:21+01:00
New Revision: a5a7a9da39c0aeb67d5a3340e1345db42c6aaed4

URL: https://github.com/llvm/llvm-project/commit/a5a7a9da39c0aeb67d5a3340e1345db42c6aaed4
DIFF: https://github.com/llvm/llvm-project/commit/a5a7a9da39c0aeb67d5a3340e1345db42c6aaed4.diff

LOG: [X86] Fix updating LiveVariables in convertToThreeAddress

Fix all instances of:
*** Bad machine code: Kill missing from LiveVariables ***
in the X86 CodeGen tests with D129213 applied, which adds verification
of LiveIntervals after the TwoAddressInstruction pass runs.

Differential Revision: https://reviews.llvm.org/D129634

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 74ef831e1658a..4904e79f98703 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -1249,6 +1249,8 @@ MachineInstr *X86InstrInfo::convertToThreeAddressWithLEA(unsigned MIOpc,
   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 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
   bool Is64Bit = Subtarget.is64Bit();
 
   bool Is8BitOp = false;
+  unsigned NumRegOperands = 2;
   unsigned MIOpc = MI.getOpcode();
   switch (MIOpc) {
   default: llvm_unreachable("Unreachable!");
@@ -1385,6 +1388,9 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
       MIB.add(ImplicitOp);
     NewMI = MIB;
 
+    // Add kills if classifyLEAReg created a new register.
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::SHL8ri:
@@ -1416,6 +1422,10 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
       MIB.add(ImplicitOp);
 
     NewMI = addOffset(MIB, 1);
+
+    // Add kills if classifyLEAReg created a new register.
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::DEC64r:
@@ -1438,6 +1448,9 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
 
     NewMI = addOffset(MIB, -1);
 
+    // Add kills if classifyLEAReg created a new register.
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::DEC8r:
@@ -1485,8 +1498,15 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
       MIB.add(ImplicitOp2);
 
     NewMI = addRegReg(MIB, SrcReg, isKill, SrcReg2, isKill2);
-    if (LV && Src2.isKill())
-      LV->replaceKillInstruction(SrcReg2, MI, *NewMI);
+
+    // Add kills if classifyLEAReg created a new register.
+    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 +1545,10 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
       MIB.add(ImplicitOp);
 
     NewMI = addOffset(MIB, MI.getOperand(2));
+
+    // Add kills if classifyLEAReg created a new register.
+    if (LV && SrcReg != Src.getReg())
+      LV->getVarInfo(SrcReg).Kills.push_back(NewMI);
     break;
   }
   case X86::ADD8ri:
@@ -1729,6 +1753,7 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
               .add(MI.getOperand(2))
               .add(Src)
               .add(MI.getOperand(3));
+    NumRegOperands = 4;
     break;
   }
   }
@@ -1736,10 +1761,11 @@ MachineInstr *X86InstrInfo::convertToThreeAddress(MachineInstr &MI,
   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();