[MachineVerifier][GlobalISel] Checking that generic instrs have LLTs on all vregs

Every generic machine instruction must have generic virtual registers
only, that is, have a low-level type attached to each operand.

Previously MachineVerifier would catch a type missing on an operand
only if the previous operand for the the same type index exists and
have a type attached to it and it will report it as a type mismatch.
This is incosistent behaviour and a misleading error message.

This commit makes sure MachineVerifier explicitly checks that the
types are there for every operand and if not provides a
straightforward error message.

Reviewers: qcolombet t.p.northover bogner ab

Reviewed By: qcolombet

Subscribers: rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D46455

llvm-svn: 331694

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 0f466e4b2d1..92abd84c56b 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1224,8 +1224,12 @@ LLT MachineInstr::getTypeToPrint(unsigned OpIdx, SmallBitVector &PrintedTypes,
   if (PrintedTypes[OpInfo.getGenericTypeIndex()])
     return LLT{};
 
-  PrintedTypes.set(OpInfo.getGenericTypeIndex());
-  return MRI.getType(Op.getReg());
+  LLT TypeToPrint = MRI.getType(Op.getReg());
+  // Don't mark the type index printed if it wasn't actually printed: maybe
+  // another operand with the same type index has an actual type attached:
+  if (TypeToPrint.isValid())
+    PrintedTypes.set(OpInfo.getGenericTypeIndex());
+  return TypeToPrint;
 }
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)