[llvm] r354401 - [GVN] Fix a non-integral pointer bug w/vector types

[Philip Reames via llvm-commits]

Author: reames
Date: Tue Feb 19 15:19:51 2019
New Revision: 354401

URL: http://llvm.org/viewvc/llvm-project?rev=354401&view=rev
Log:
[GVN] Fix a non-integral pointer bug w/vector types

GVN generally doesn't forward structs or array types, but it *will* forward vector types to non-vectors and vice versa.  As demonstrated in tests, we need to inhibit the same set of transforms for vector of non-integral pointers as for non-integral pointers themselves.


Modified:
    llvm/trunk/lib/Transforms/Utils/VNCoercion.cpp
    llvm/trunk/test/Transforms/GVN/non-integral-pointers.ll

Modified: llvm/trunk/lib/Transforms/Utils/VNCoercion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/VNCoercion.cpp?rev=354401&r1=354400&r2=354401&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/VNCoercion.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/VNCoercion.cpp Tue Feb 19 15:19:51 2019
@@ -31,8 +31,8 @@ bool canCoerceMustAliasedValueToLoad(Val
     return false;
 
   // Don't coerce non-integral pointers to integers or vice versa.
-  if (DL.isNonIntegralPointerType(StoredVal->getType()) !=
-      DL.isNonIntegralPointerType(LoadTy)) {
+  if (DL.isNonIntegralPointerType(StoredVal->getType()->getScalarType()) !=
+      DL.isNonIntegralPointerType(LoadTy->getScalarType())) {
     // As a special case, allow coercion of memset used to initialize
     // an array w/null.  Despite non-integral pointers not generally having a
     // specific bit pattern, we do assume null is zero.

Modified: llvm/trunk/test/Transforms/GVN/non-integral-pointers.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/non-integral-pointers.ll?rev=354401&r1=354400&r2=354401&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/non-integral-pointers.ll (original)
+++ llvm/trunk/test/Transforms/GVN/non-integral-pointers.ll Tue Feb 19 15:19:51 2019
@@ -77,6 +77,22 @@ define i8 addrspace(4)* @neg_forward_mem
   ret i8 addrspace(4)* %ref
 }
 
+define <1 x i8 addrspace(4)*> @neg_forward_memset_vload(<1 x i8 addrspace(4)*> addrspace(4)* %loc) {
+; CHECK-LABEL: @neg_forward_memset_vload(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[LOC_BC:%.*]] = bitcast <1 x i8 addrspace(4)*> addrspace(4)* [[LOC:%.*]] to i8 addrspace(4)*
+; CHECK-NEXT:    call void @llvm.memset.p4i8.i64(i8 addrspace(4)* align 4 [[LOC_BC]], i8 7, i64 8, i1 false)
+; CHECK-NEXT:    [[REF:%.*]] = load <1 x i8 addrspace(4)*>, <1 x i8 addrspace(4)*> addrspace(4)* [[LOC]]
+; CHECK-NEXT:    ret <1 x i8 addrspace(4)*> [[REF]]
+;
+  entry:
+  %loc.bc = bitcast <1 x i8 addrspace(4)*> addrspace(4)* %loc to i8 addrspace(4)*
+  call void @llvm.memset.p4i8.i64(i8 addrspace(4)* align 4 %loc.bc, i8 7, i64 8, i1 false)
+  %ref = load <1 x i8 addrspace(4)*>, <1 x i8 addrspace(4)*> addrspace(4)* %loc
+  ret <1 x i8 addrspace(4)*> %ref
+}
+
+
 ; Can forward since we can do so w/o breaking types
 define i8 addrspace(4)* @forward_memset_zero(i8 addrspace(4)* addrspace(4)* %loc) {
 ; CHECK-LABEL: @forward_memset_zero(
@@ -108,6 +124,21 @@ define i8 addrspace(4)* @neg_forward_sto
   ret i8 addrspace(4)* %ref
 }
 
+define <1 x i8 addrspace(4)*> @neg_forward_store_vload(<1 x i8 addrspace(4)*> addrspace(4)* %loc) {
+; CHECK-LABEL: @neg_forward_store_vload(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[LOC_BC:%.*]] = bitcast <1 x i8 addrspace(4)*> addrspace(4)* [[LOC:%.*]] to i64 addrspace(4)*
+; CHECK-NEXT:    store i64 5, i64 addrspace(4)* [[LOC_BC]]
+; CHECK-NEXT:    [[REF:%.*]] = load <1 x i8 addrspace(4)*>, <1 x i8 addrspace(4)*> addrspace(4)* [[LOC]]
+; CHECK-NEXT:    ret <1 x i8 addrspace(4)*> [[REF]]
+;
+  entry:
+  %loc.bc = bitcast <1 x i8 addrspace(4)*> addrspace(4)* %loc to i64 addrspace(4)*
+  store i64 5, i64 addrspace(4)* %loc.bc
+  %ref = load <1 x i8 addrspace(4)*>, <1 x i8 addrspace(4)*> addrspace(4)* %loc
+  ret <1 x i8 addrspace(4)*> %ref
+}
+
 ; TODO: missed optimization, we can forward the null.
 define i8 addrspace(4)* @forward_store_zero(i8 addrspace(4)* addrspace(4)* %loc) {
 ; CHECK-LABEL: @forward_store_zero(