[llvm-commits] [PATCH] Machine code verifier pass

[Evan Cheng]

Thanks Jakob! So comments below:

+    const MachineBasicBlock *MBB;
+    BBInfo *MBBInfo;
+    const MachineInstr *MI;
+    const MachineOperand *MO;

I find it strange that these are class ivars. Can you change them to  
local variables and parameters?


+void
+MachineVerifier::calcMaxRegsPassed()
+{
+  // First push live-out regs to successors' vregsPassed. Remember  
the MBBs that
+  // have any vregsPassed.
+  DenseSet<const MachineBasicBlock*> todo;
+  for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF- 
 >end();
+       MFI != MFE; ++MFI) {
+    const MachineBasicBlock &MBB(*MFI);
+    BBInfo &MInfo = MBBInfoMap[&MBB];
+    for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
+           SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
+      BBInfo &SInfo = MBBInfoMap[*SuI];
+      if (SInfo.addPassed(MInfo.regsLiveOut))
+        todo.insert(*SuI);
+    }
+  }
+
+  // Iteratively push vregsPassed to successors until convergence.
+  while (!todo.empty()) {

I don't think the order of iteration of DenseSet is deterministic.

+    // If any regs removed, we need to recheck successors

Missing a period at the end of the sentence.

Have you had a chance running this through some code?

Thanks,

Evan

On May 8, 2009, at 2:38 PM, Jakob Stoklund Olesen wrote:

> Hi,
>
> The attached patch creates a machine code verifier pass, enabled  
> with -verify-machineinstrs. The verifier pass is run immediately  
> after -print-machineinstrs would run. It verifies the following:
>
> Operand counts: All explicit operands must be present.
>
> Register classes: All physical and virtual register operands must be  
> compatible with the register class required by the instruction  
> descriptor.
>
> Register live intervals: Registers must be defined only once, and  
> must be defined before use.
>
> The double-definition checking is disabled until LiveVariables has  
> run.
>
> If I have misunderstood something about valid machine code, please  
> let me know.
>
> <machine-verifier.patch>
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