[GlobalISel] Set, require, and verify Legalized MF property.

RegBankSelect and InstructionSelect run after the legalizer and
require a Legalized function: check that all instructions are legal.

Note that this should be in the MachineVerifier, but it can't use the
MachineLegalizer as it's currently in the separate GlobalISel library.
Note that the RegBankSelect verifier checks have the same layering
problem, but we only use inline methods so end up not needing to link
against the GlobalISel library.

llvm-svn: 277472

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp b/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
index 6248ab46097..bf88d742dba 100644
--- a/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp
@@ -12,6 +12,7 @@
 
 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
 #include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/GlobalISel/MachineLegalizer.h"
 #include "llvm/CodeGen/GlobalISel/RegisterBank.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
@@ -542,6 +543,26 @@ bool RegBankSelect::runOnMachineFunction(MachineFunction &MF) {
   if (F->hasFnAttribute(Attribute::OptimizeNone))
     OptMode = Mode::Fast;
   init(MF);
+
+#ifndef NDEBUG
+  // Check that our input is fully legal: we require the function to have the
+  // Legalized property, so it should be.
+  // FIXME: This should be in the MachineVerifier, but it can't use the
+  // MachineLegalizer as it's currently in the separate GlobalISel library.
+  if (const MachineLegalizer *MLI = MF.getSubtarget().getMachineLegalizer()) {
+    for (const MachineBasicBlock &MBB : MF) {
+      for (const MachineInstr &MI : MBB) {
+        if (isPreISelGenericOpcode(MI.getOpcode()) && !MLI->isLegal(MI)) {
+          std::string ErrStorage;
+          raw_string_ostream Err(ErrStorage);
+          Err << "Instruction is not legal: " << MI << '\n';
+          report_fatal_error(Err.str());
+        }
+      }
+    }
+  }
+#endif
+
   // Walk the function and assign register banks to all operands.
   // Use a RPOT to make sure all registers are assigned before we choose
   // the best mapping of the current instruction.