From b252987fe34a314524428d27a85a87fdd746e0b5 Mon Sep 17 00:00:00 2001
From: Yichao Yu <yyc1992@gmail.com>
Date: Sun, 18 Jun 2017 16:45:38 -0400
Subject: [PATCH 2/4] Disable LoadCSE and Store forwarding between different
 address space or between non-integral pointer and integers.

---
 lib/Analysis/Loads.cpp                             | 30 +++++++++++++++++++
 .../InstCombine/non-integral-pointers.ll           | 34 ++++++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/lib/Analysis/Loads.cpp b/lib/Analysis/Loads.cpp
index 591b0fc481d..e9c8be82b03 100644
--- a/lib/Analysis/Loads.cpp
+++ b/lib/Analysis/Loads.cpp
@@ -380,6 +380,21 @@ Value *llvm::FindAvailablePtrLoadStore(Value *Ptr, Type *AccessTy,
         if (LI->isAtomic() < AtLeastAtomic)
           return nullptr;
 
+        if (AccessTy->isPointerTy()) {
+          PointerType *Ty1 = cast<PointerType>(AccessTy);
+          if (PointerType *Ty2 = dyn_cast<PointerType>(LI->getType())) {
+            if (Ty1->getAddressSpace() != Ty2->getAddressSpace()) {
+              return nullptr;
+            }
+          }
+          else if (DL.isNonIntegralPointerType(Ty1)) {
+            return nullptr;
+          }
+        }
+        else if (DL.isNonIntegralPointerType(LI->getType())) {
+          return nullptr;
+        }
+
         if (IsLoadCSE)
             *IsLoadCSE = true;
         return LI;
@@ -399,6 +414,21 @@ Value *llvm::FindAvailablePtrLoadStore(Value *Ptr, Type *AccessTy,
         if (SI->isAtomic() < AtLeastAtomic)
           return nullptr;
 
+        if (AccessTy->isPointerTy()) {
+          PointerType *Ty1 = cast<PointerType>(AccessTy);
+          if (PointerType *Ty2 = dyn_cast<PointerType>(SI->getValueOperand()->getType())) {
+            if (Ty1->getAddressSpace() != Ty2->getAddressSpace()) {
+              return nullptr;
+            }
+          }
+          else if (DL.isNonIntegralPointerType(Ty1)) {
+            return nullptr;
+          }
+        }
+        else if (DL.isNonIntegralPointerType(SI->getValueOperand()->getType())) {
+          return nullptr;
+        }
+
         if (IsLoadCSE)
           *IsLoadCSE = false;
         return SI->getOperand(0);
diff --git a/test/Transforms/InstCombine/non-integral-pointers.ll b/test/Transforms/InstCombine/non-integral-pointers.ll
index 4f54fe6737d..96a2b2edaf1 100644
--- a/test/Transforms/InstCombine/non-integral-pointers.ll
+++ b/test/Transforms/InstCombine/non-integral-pointers.ll
@@ -46,3 +46,37 @@ entry:
   store i8 addrspace(3)* %val, i8 addrspace(3)** %ptr1
   ret void
 }
+
+define i64 @g(i8 addrspace(4)** %gp) {
+  ; CHECK-LABEL: @g(
+  ; CHECK: load
+  %.pre = load i8 addrspace(4)*, i8 addrspace(4)** %gp, align 8
+  %v74 = call i8 addrspace(4)* @alloc()
+  %v75 = addrspacecast i8 addrspace(4)* %v74 to i8*
+  %v76 = bitcast i8* %v75 to i8 addrspace(4)**
+  %v77 = getelementptr i8 addrspace(4)*, i8 addrspace(4)** %v76, i64 -1
+  ; CHECK: store
+  store i8 addrspace(4)* %.pre, i8 addrspace(4)** %v77, align 8
+  %v80 = bitcast i8 addrspace(4)** %v77 to i64*
+  ; CHECK: load
+  ; CHECK-NOT: ptrtoint
+  %v81 = load i64, i64* %v80, align 8
+  ret i64 %v81
+}
+
+define i64 @g2(i8* addrspace(4)* %gp) {
+  ; CHECK-LABEL: @g2(
+  ; CHECK: load
+  %.pre = load i8*, i8* addrspace(4)* %gp, align 8
+  %v74 = call i8 addrspace(4)* @alloc()
+  %v76 = bitcast i8 addrspace(4)* %v74 to i8* addrspace(4)*
+  %v77 = getelementptr i8*, i8* addrspace(4)* %v76, i64 -1
+  ; CHECK: store
+  store i8* %.pre, i8* addrspace(4)* %v77, align 8
+  %v80 = bitcast i8* addrspace(4)* %v77 to i64 addrspace(4)*
+  ; CHECK-NOT: store
+  %v81 = load i64, i64 addrspace(4)* %v80, align 8
+  ret i64 %v81
+}
+
+declare i8 addrspace(4)* @alloc()
-- 
2.14.1