[llvm] 2f13e63 - [LegalizeDAG] Add asserts to verify the types of custom legalized operation matches the original node.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2021-03-22T10:28:51-07:00
New Revision: 2f13e63f9eefa36013f3165523d5e193bc1598ad

URL: https://github.com/llvm/llvm-project/commit/2f13e63f9eefa36013f3165523d5e193bc1598ad
DIFF: https://github.com/llvm/llvm-project/commit/2f13e63f9eefa36013f3165523d5e193bc1598ad.diff

LOG: [LegalizeDAG] Add asserts to verify the types of custom legalized operation matches the original node.

We've messed this up a few times recently on RISCV. Experiments
with these asserts found a couple issues on other targets as well.
They've all been cleaned up now so we can put in these asserts to
catch future issues

I had to waive Glue because ADDC/ADDE/etc legalization replaces
Glue with i32 on at least AArch64. X86 used to do the same before
we switched to ADDCARRY. So I guess that's just how that works.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D98979

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 5308bc983a3a..1a131bf32ef1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1259,6 +1259,11 @@ void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
           return;
 
         if (Node->getNumValues() == 1) {
+          // Verify the new types match the original. Glue is waived because
+          // ISD::ADDC can be legalized by replacing Glue with an integer type.
+          assert((Res.getValueType() == Node->getValueType(0) ||
+                  Node->getValueType(0) == MVT::Glue) &&
+                 "Type mismatch for custom legalized operation");
           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
           // We can just directly replace this node with the lowered value.
           ReplaceNode(SDValue(Node, 0), Res);
@@ -1266,8 +1271,14 @@ void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
         }
 
         SmallVector<SDValue, 8> ResultVals;
-        for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
+        for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i) {
+          // Verify the new types match the original. Glue is waived because
+          // ISD::ADDC can be legalized by replacing Glue with an integer type.
+          assert((Res->getValueType(i) == Node->getValueType(i) ||
+                  Node->getValueType(i) == MVT::Glue) &&
+                 "Type mismatch for custom legalized operation");
           ResultVals.push_back(Res.getValue(i));
+        }
         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
         ReplaceNode(Node, ResultVals.data());
         return;