[llvm] 875891a - [MemoryDependence] Fix invariant group store

[William S. Moses via llvm-commits]

Author: William S. Moses
Date: 2021-03-09T19:03:39-05:00
New Revision: 875891a10d50a791d3f076c9259e60af6c9af18c

URL: https://github.com/llvm/llvm-project/commit/875891a10d50a791d3f076c9259e60af6c9af18c
DIFF: https://github.com/llvm/llvm-project/commit/875891a10d50a791d3f076c9259e60af6c9af18c.diff

LOG: [MemoryDependence] Fix invariant group store

Fix bug in MemoryDependence [and thus GVN] for invariant group.

Previously MemDep didn't verify that the store was storing into a
pointer rather than a store simply using a pointer.

Differential Revision: https://reviews.llvm.org/D98267

Added: 
    llvm/test/Transforms/GVN/storeinvgroup.ll

Modified: 
    llvm/lib/Analysis/MemoryDependenceAnalysis.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index 895936d47175..886b5bf4acd3 100644
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -344,7 +344,9 @@ MemoryDependenceResults::getInvariantGroupPointerDependency(LoadInst *LI,
       // If we hit load/store with the same invariant.group metadata (and the
       // same pointer operand) we can assume that value pointed by pointer
       // operand didn't change.
-      if ((isa<LoadInst>(U) || isa<StoreInst>(U)) &&
+      if ((isa<LoadInst>(U) ||
+           (isa<StoreInst>(U) &&
+            cast<StoreInst>(U)->getPointerOperand() == Ptr)) &&
           U->hasMetadata(LLVMContext::MD_invariant_group))
         ClosestDependency = GetClosestDependency(ClosestDependency, U);
     }

diff  --git a/llvm/test/Transforms/GVN/storeinvgroup.ll b/llvm/test/Transforms/GVN/storeinvgroup.ll
new file mode 100644
index 000000000000..16da4b8cd424
--- /dev/null
+++ b/llvm/test/Transforms/GVN/storeinvgroup.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -gvn -S -o - < %s | FileCheck %s
+
+define double @code(double* %a1) {
+; CHECK-LABEL: @code(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[META:%.*]] = alloca double*, align 8
+; CHECK-NEXT:    store double 1.234500e+00, double* [[A1:%.*]], align 8
+; CHECK-NEXT:    store double* [[A1]], double** [[META]], align 8, !invariant.group !0
+; CHECK-NEXT:    ret double 1.234500e+00
+;
+entry:
+  %meta = alloca double*
+  store double 1.23450000e+00, double* %a1, align 8
+  store double* %a1, double** %meta, align 8, !invariant.group !0
+  %iload = load double, double* %a1, align 8, !invariant.group !1
+  ret double %iload
+}
+
+!0 = distinct !{}
+!1 = distinct !{}