From 3c1bb4a3f889361888c6744216008ef36257b44a Mon Sep 17 00:00:00 2001
From: "Venevtsev, Igor" <igor.venevtsev@intel.com>
Date: Mon, 18 Mar 2019 12:24:24 +0100
Subject: [PATCH] ptrOffset and ptrDiff do not truncate uint64_t to uintptr_t

Change-Id: I0dcaf058ae3244ca0168580d972a19f9e4692e05
Signed-off-by: Venevtsev, Igor <igor.venevtsev@intel.com>
---
 runtime/helpers/ptr_math.h            | 10 ++++++++++
 unit_tests/helpers/ptr_math_tests.cpp | 20 ++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/runtime/helpers/ptr_math.h b/runtime/helpers/ptr_math.h
index b18b5d2664..b9fedde6d4 100644
--- a/runtime/helpers/ptr_math.h
+++ b/runtime/helpers/ptr_math.h
@@ -23,6 +23,11 @@ inline T ptrOffset(T ptrBefore, size_t offset) {
     return (T)addrAfter;
 }
 
+template <>
+inline uint64_t ptrOffset(uint64_t ptrBefore, size_t offset) {
+    return ptrBefore + offset;
+}
+
 template <typename TA, typename TB>
 inline size_t ptrDiff(TA ptrAfter, TB ptrBefore) {
     auto addrBefore = (uintptr_t)ptrBefore;
@@ -30,6 +35,11 @@ inline size_t ptrDiff(TA ptrAfter, TB ptrBefore) {
     return addrAfter - addrBefore;
 }
 
+template <typename T>
+inline uint64_t ptrDiff(uint64_t ptrAfter, T ptrBefore) {
+    return ptrAfter - ptrBefore;
+}
+
 template <typename IntegerAddressType>
 inline void *addrToPtr(IntegerAddressType addr) {
     uintptr_t correctBitnessAddress = static_cast<uintptr_t>(addr);
diff --git a/unit_tests/helpers/ptr_math_tests.cpp b/unit_tests/helpers/ptr_math_tests.cpp
index 8657bee1a9..2e8104cc22 100644
--- a/unit_tests/helpers/ptr_math_tests.cpp
+++ b/unit_tests/helpers/ptr_math_tests.cpp
@@ -45,3 +45,23 @@ TEST(PtrMath, givenCastToUint64FunctionWhenItIsCalledThenProperValueIsReturned)
     auto uintAddress = castToUint64(addressWithTrailingBitSet);
     EXPECT_EQ(uintAddress, expectedUint64Address);
 }
+
+TEST(ptrOffset, preserve64Bit) {
+    uint64_t ptrBefore = 0x800000000;
+    size_t offset = 0x1234;
+    auto ptrAfter = ptrOffset(ptrBefore, offset);
+    EXPECT_EQ(0x800001234ull, ptrAfter);
+}
+
+TEST(ptrDiff, preserve64Bit) {
+    auto ptrAfter = 0x800001234ull;
+
+    auto ptrBefore = ptrDiff(ptrAfter, (size_t)0x1234);
+    EXPECT_EQ(0x800000000ull, ptrBefore);
+
+    auto ptrBefore2 = ptrDiff(ptrAfter, 0x1234);
+    EXPECT_EQ(0x800000000ull, ptrBefore2);
+
+    auto ptrBefore3 = ptrDiff(ptrAfter, 0x1234ull);
+    EXPECT_EQ(0x800000000ull, ptrBefore3);
+}