[llvm] r277854 - [ConstantFolding] Don't create illegal (non-integral) inttoptrs

[Sanjoy Das via llvm-commits]

Author: sanjoy
Date: Fri Aug  5 14:23:29 2016
New Revision: 277854

URL: http://llvm.org/viewvc/llvm-project?rev=277854&view=rev
Log:
[ConstantFolding] Don't create illegal (non-integral) inttoptrs

Reviewers: majnemer, arsenm

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23182

Added:
    llvm/trunk/test/Transforms/InstCombine/non-integral-pointers.ll
Modified:
    llvm/trunk/lib/Analysis/ConstantFolding.cpp

Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=277854&r1=277853&r2=277854&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
+++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Fri Aug  5 14:23:29 2016
@@ -828,7 +828,9 @@ Constant *SymbolicallyEvaluateGEP(const
     }
   }
 
-  if (Ptr->isNullValue() || BasePtr != 0) {
+  auto *PTy = cast<PointerType>(Ptr->getType());
+  if ((Ptr->isNullValue() || BasePtr != 0) &&
+      !DL.isNonIntegralPointerType(PTy)) {
     Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
     return ConstantExpr::getIntToPtr(C, ResTy);
   }
@@ -837,8 +839,7 @@ Constant *SymbolicallyEvaluateGEP(const
   // we eliminate over-indexing of the notional static type array bounds.
   // This makes it easy to determine if the getelementptr is "inbounds".
   // Also, this helps GlobalOpt do SROA on GlobalVariables.
-  Type *Ty = Ptr->getType();
-  assert(Ty->isPointerTy() && "Forming regular GEP of non-pointer type");
+  Type *Ty = PTy;
   SmallVector<Constant *, 32> NewIdxs;
 
   do {

Added: llvm/trunk/test/Transforms/InstCombine/non-integral-pointers.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/non-integral-pointers.ll?rev=277854&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/non-integral-pointers.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/non-integral-pointers.ll Fri Aug  5 14:23:29 2016
@@ -0,0 +1,20 @@
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:4"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i8 addrspace(4)* @f_0() {
+; CHECK-LABEL: @f_0(
+; CHECK: ret i8 addrspace(4)* getelementptr (i8, i8 addrspace(4)* null, i64 50)
+  %result = getelementptr i8, i8 addrspace(4)* null, i64 50
+  ret i8 addrspace(4)* %result
+}
+
+define i8 addrspace(3)* @f_1() {
+; inttoptr is fine here since addrspace(3) is integral.
+
+; CHECK-LABEL: @f_1(
+; CHECK: ret i8 addrspace(3)* inttoptr (i64 50 to i8 addrspace(3)*)
+  %result = getelementptr i8, i8 addrspace(3)* null, i64 50
+  ret i8 addrspace(3)* %result
+}