[PATCH] D45344: Fold malloc + memset to calloc even for llvm.memset

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 created this revision.
xbolva00 added reviewers: dlj, ab, spatel, dblaikie.
Herald added a subscriber: llvm-commits.

Repository:
  rL LLVM

https://reviews.llvm.org/D45344

Files:
  SimplifyLibCalls.cpp


Index: SimplifyLibCalls.cpp
===================================================================
--- SimplifyLibCalls.cpp
+++ SimplifyLibCalls.cpp
@@ -840,12 +840,8 @@
   if (!FillValue || FillValue->getZExtValue() != 0)
     return nullptr;
 
-  // TODO: We should handle the case where the malloc has more than one use.
-  // This is necessary to optimize common patterns such as when the result of
-  // the malloc is checked against null or when a memset intrinsic is used in
-  // place of a memset library call.
   auto *Malloc = dyn_cast<CallInst>(Memset->getArgOperand(0));
-  if (!Malloc || !Malloc->hasOneUse())
+  if (!Malloc)
     return nullptr;
 
   // Is the inner call really malloc()?
@@ -2219,7 +2215,8 @@
       return optimizeLog(CI, Builder);
     case Intrinsic::sqrt:
       return optimizeSqrt(CI, Builder);
-    // TODO: Use foldMallocMemset() with memset intrinsic.
+    case Intrinsic::memset:
+      return foldMallocMemset(CI, Builder, *TLI);
     default:
       return nullptr;
     }
@@ -2393,7 +2390,8 @@
 
 Value *FortifiedLibCallSimplifier::optimizeMemSetChk(CallInst *CI,
                                                      IRBuilder<> &B) {
-  // TODO: Try foldMallocMemset() here.
+  if (auto *Calloc = foldMallocMemset(CI, B, *TLI))
+    return Calloc;
 
   if (isFortifiedCallFoldable(CI, 3, 2, false)) {
     Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);


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