[llvm-commits] [llvm] r162849 - /llvm/trunk/lib/CodeGen/MachineVerifier.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Wed Aug 29 13:11:05 2012
New Revision: 162849

URL: http://llvm.org/viewvc/llvm-project?rev=162849&view=rev
Log:
Verify the consistency of inline asm operands.

The operands on an INLINEASM machine instruction are divided into groups
headed by immediate flag operands. Verify this structure.

Extract verifyTiedOperands(), and only call it for non-inlineasm
instructions.

Modified:
    llvm/trunk/lib/CodeGen/MachineVerifier.cpp

Modified: llvm/trunk/lib/CodeGen/MachineVerifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineVerifier.cpp?rev=162849&r1=162848&r2=162849&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineVerifier.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineVerifier.cpp Wed Aug 29 13:11:05 2012
@@ -24,6 +24,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/BasicBlock.h"
+#include "llvm/InlineAsm.h"
 #include "llvm/Instructions.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/LiveVariables.h"
@@ -213,6 +214,9 @@
     void report(const char *msg, const MachineBasicBlock *MBB,
                 const LiveInterval &LI);
 
+    void verifyInlineAsm(const MachineInstr *MI);
+    void verifyTiedOperands(const MachineInstr *MI);
+
     void checkLiveness(const MachineOperand *MO, unsigned MONum);
     void markReachable(const MachineBasicBlock *MBB);
     void calcRegsPassed();
@@ -695,42 +699,94 @@
   }
 }
 
-void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
-  const MCInstrDesc &MCID = MI->getDesc();
-  if (MI->getNumOperands() < MCID.getNumOperands()) {
-    report("Too few operands", MI);
-    *OS << MCID.getNumOperands() << " operands expected, but "
-        << MI->getNumExplicitOperands() << " given.\n";
+// The operands on an INLINEASM instruction must follow a template.
+// Verify that the flag operands make sense.
+void MachineVerifier::verifyInlineAsm(const MachineInstr *MI) {
+  // The first two operands on INLINEASM are the asm string and global flags.
+  if (MI->getNumOperands() < 2) {
+    report("Too few operands on inline asm", MI);
+    return;
+  }
+  if (!MI->getOperand(0).isSymbol())
+    report("Asm string must be an external symbol", MI);
+  if (!MI->getOperand(1).isImm())
+    report("Asm flags must be an immediate", MI);
+  // Allowed flags are Extra_HasSideEffects = 1, and Extra_IsAlignStack = 2.
+  if (!isUInt<2>(MI->getOperand(1).getImm()))
+    report("Unknown asm flags", &MI->getOperand(1), 1);
+
+  assert(InlineAsm::MIOp_FirstOperand == 2 && "Asm format changed");
+
+  unsigned OpNo = InlineAsm::MIOp_FirstOperand;
+  unsigned NumOps;
+  for (unsigned e = MI->getNumOperands(); OpNo < e; OpNo += NumOps) {
+    const MachineOperand &MO = MI->getOperand(OpNo);
+    // There may be implicit ops after the fixed operands.
+    if (!MO.isImm())
+      break;
+    NumOps = 1 + InlineAsm::getNumOperandRegisters(MO.getImm());
   }
 
-  // Check the tied operands.
-  SmallVector<unsigned, 4> TiedDefs;
-  SmallVector<unsigned, 4> TiedUses;
+  if (OpNo > MI->getNumOperands())
+    report("Missing operands in last group", MI);
+
+  // An optional MDNode follows the groups.
+  if (OpNo < MI->getNumOperands() && MI->getOperand(OpNo).isMetadata())
+    ++OpNo;
+
+  // All trailing operands must be implicit registers.
+  for (unsigned e = MI->getNumOperands(); OpNo < e; ++OpNo) {
+    const MachineOperand &MO = MI->getOperand(OpNo);
+    if (!MO.isReg() || !MO.isImplicit())
+      report("Expected implicit register after groups", &MO, OpNo);
+  }
+}
+
+// Verify the consistency of tied operands.
+void MachineVerifier::verifyTiedOperands(const MachineInstr *MI) {
+  const MCInstrDesc &MCID = MI->getDesc();
+  SmallVector<unsigned, 4> Defs;
+  SmallVector<unsigned, 4> Uses;
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = MI->getOperand(i);
     if (!MO.isReg() || !MO.isTied())
       continue;
     if (MO.isDef()) {
-      TiedDefs.push_back(i);
+      Defs.push_back(i);
       continue;
     }
-    TiedUses.push_back(i);
-    if (TiedDefs.size() < TiedUses.size()) {
+    Uses.push_back(i);
+    if (Defs.size() < Uses.size()) {
       report("No tied def for tied use", &MO, i);
       break;
     }
     if (i >= MCID.getNumOperands())
       continue;
     int DefIdx = MCID.getOperandConstraint(i, MCOI::TIED_TO);
-    if (unsigned(DefIdx) != TiedDefs[TiedUses.size() - 1]) {
-      report("Tied def doesn't match MCInstrDesc", &MO, i);
+    if (unsigned(DefIdx) != Defs[Uses.size() - 1]) {
+      report(" def doesn't match MCInstrDesc", &MO, i);
       *OS << "Descriptor says tied def should be operand " << DefIdx << ".\n";
     }
   }
-  if (TiedDefs.size() > TiedUses.size()) {
-    unsigned i = TiedDefs[TiedUses.size() - 1];
+  if (Defs.size() > Uses.size()) {
+    unsigned i = Defs[Uses.size() - 1];
     report("No tied use for tied def", &MI->getOperand(i), i);
   }
+}
+
+void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
+  const MCInstrDesc &MCID = MI->getDesc();
+  if (MI->getNumOperands() < MCID.getNumOperands()) {
+    report("Too few operands", MI);
+    *OS << MCID.getNumOperands() << " operands expected, but "
+        << MI->getNumExplicitOperands() << " given.\n";
+  }
+
+  // Check the tied operands.
+  if (MI->isInlineAsm())
+    verifyInlineAsm(MI);
+  else
+    verifyTiedOperands(MI);
 
   // Check the MachineMemOperands for basic consistency.
   for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),