[PATCH] D132931: [Attributor] Simplify offset calculation for a constant GEP

[Sameer Sahasrabuddhe via Phabricator via llvm-commits]

sameerds created this revision.
Herald added subscribers: ormris, okura, jdoerfert, kuter, hiraditya.
Herald added a reviewer: homerdin.
Herald added a project: All.
sameerds requested review of this revision.
Herald added a reviewer: jdoerfert.
Herald added a reviewer: sstefan1.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D132931

Files:
  llvm/lib/Transforms/IPO/AttributorAttributes.cpp


Index: llvm/lib/Transforms/IPO/AttributorAttributes.cpp
===================================================================
--- llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -1287,19 +1287,12 @@
           return true;
         }
 
-        SmallVector<Value *, 8> Indices;
-        for (Use &Idx : GEP->indices()) {
-          if (auto *CIdx = dyn_cast<ConstantInt>(Idx)) {
-            Indices.push_back(CIdx);
-            continue;
-          }
+        APInt GEPOffset(DL.getIndexTypeSizeInBits(GEP->getType()), 0);
+        bool CannotFail = GEP->accumulateConstantOffset(DL, GEPOffset);
+        assert(CannotFail);
+        (void)CannotFail;
 
-          LLVM_DEBUG(dbgs() << "[AAPointerInfo] Non constant GEP index " << *GEP
-                            << " : " << *Idx << "\n");
-          return false;
-        }
-        UsrOI.Offset = PtrOI.Offset + DL.getIndexedOffsetInType(
-                                          GEP->getSourceElementType(), Indices);
+        UsrOI.Offset = PtrOI.Offset + GEPOffset.getZExtValue();
         Follow = true;
         return true;
       }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D132931.456620.patch
Type: text/x-patch
Size: 1153 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220830/d8ecd574/attachment.bin>