[globalisel][verifier] Run the MachineVerifier from IRTranslator onwards

-verify-machineinstrs inserts the MachineVerifier after every MachineInstr-based
pass. However, GlobalISel creates MachineInstr-based passes earlier than DAGISel
and the corresponding verifiers are not being added. This patch fixes that.

If GlobalISel triggers the fallback path then the MIR can be left in a bad
state that is going to be cleared by ResetMachineFunctions. In this situation
verifying between GlobalISel passes will prevent the fallback path from
recovering from this. As a result, we bail out of verifying a function if the
FailedISel attribute is present.

llvm-svn: 343613

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -364,6 +364,13 @@ unsigned MachineVerifier::verify(MachineFunction &MF) {
 
   const bool isFunctionFailedISel = MF.getProperties().hasProperty(
       MachineFunctionProperties::Property::FailedISel);
+
+  // If we're mid-GlobalISel and we already triggered the fallback path then
+  // it's expected that the MIR is somewhat broken but that's ok since we'll
+  // reset it and clear the FailedISel attribute in ResetMachineFunctions.
+  if (isFunctionFailedISel)
+    return foundErrors;
+
   isFunctionRegBankSelected =
       !isFunctionFailedISel &&
       MF.getProperties().hasProperty(

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -39,6 +39,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Threading.h"
+#include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils.h"
@@ -726,6 +727,7 @@ bool TargetPassConfig::addCoreISelPasses() {
        TM->Options.EnableGlobalISel && EnableFastISelOption != cl::BOU_TRUE)) {
     TM->setFastISel(false);
 
+    SaveAndRestore<bool> SavedAddingMachinePasses(AddingMachinePasses, true);
     if (addIRTranslator())
       return true;