[PATCH] D158115: [SelectionDAG][RISCV][SVE] Harden fixed offset version of ComputeValueVTs against scalable offsets.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: paulwalker-arm, efriedma, sdesmalen, eopXD, kmclaughlin.
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Use getFixedValue instead of getKnownMinValue to convert TypeSize
to uint64_t. I believe this would have caught the bug fixed by
D157872 <https://reviews.llvm.org/D157872>.

To prevent false failures, I had to treat a scalable 0 as if it
is fixed value.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D158115

Files:
  llvm/lib/CodeGen/Analysis.cpp


Index: llvm/lib/CodeGen/Analysis.cpp
===================================================================
--- llvm/lib/CodeGen/Analysis.cpp
+++ llvm/lib/CodeGen/Analysis.cpp
@@ -144,7 +144,10 @@
   if (FixedOffsets) {
     ComputeValueVTs(TLI, DL, Ty, ValueVTs, &Offsets, Offset);
     for (TypeSize Offset : Offsets) {
-      FixedOffsets->push_back(Offset.isZero() ? Offset.getKnownMinValue() : Offset.getFixedValue());
+      // Treat scalable zero as if it is fixed. Otherwise use getFixedValued
+      // to get an assert for scalable offsets.
+      FixedOffsets->push_back(Offset.isZero() ? Offset.getKnownMinValue()
+                                              : Offset.getFixedValue());
     }
   } else {
     ComputeValueVTs(TLI, DL, Ty, ValueVTs, nullptr, Offset);
@@ -170,7 +173,10 @@
   if (FixedOffsets) {
     ComputeValueVTs(TLI, DL, Ty, ValueVTs, MemVTs, &Offsets, Offset);
     for (TypeSize Offset : Offsets) {
-      FixedOffsets->push_back(Offset.isZero() ? Offset.getKnownMinValue() : Offset.getFixedValue());
+      // Treat scalable zero as if it is fixed. Otherwise use getFixedValued
+      // to get an assert for scalable offsets.
+      FixedOffsets->push_back(Offset.isZero() ? Offset.getKnownMinValue()
+                                              : Offset.getFixedValue());
     }
   } else {
     ComputeValueVTs(TLI, DL, Ty, ValueVTs, MemVTs, nullptr, Offset);


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