[llvm] [ADT] DenseMapInfo<unsigned long>::getHashValue - avoid MSVC out of bounds shift warning (PR #96173)
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 20 05:06:20 PDT 2024
https://github.com/RKSimon updated https://github.com/llvm/llvm-project/pull/96173
>From c213d8cb04abe37bf94ad9389cfcd6ba324d4e2b Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Thu, 20 Jun 2024 12:36:48 +0100
Subject: [PATCH 1/3] [ADT] DenseMapInfo<unsigned long>::getHashValue - avoid
MSVC out of bounds shift warning
Fixes MSVC warning after #95734 - despite it taking the `sizeof(Val) == 4` path, it still warns that the 32-bit unsigned long shift by 32 is out of bounds, so avoid it by converting the hard coded shift amount to be based off sizeof() instead.
---
llvm/include/llvm/ADT/DenseMapInfo.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
index 4f0aaa1ad48bb..3d83a2c1473f5 100644
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -142,7 +142,7 @@ template<> struct DenseMapInfo<unsigned long> {
if constexpr (sizeof(Val) == 4)
return DenseMapInfo<unsigned>::getHashValue(Val);
else
- return detail::combineHashValue(Val >> 32, Val);
+ return detail::combineHashValue(Val >> (4 * sizeof(Val)), Val);
}
static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
>From c484ded6a017f4400a6099af66706d0f35b9de2b Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Thu, 20 Jun 2024 12:46:14 +0100
Subject: [PATCH 2/3] Use densemap::detail::mix(Val) instead
---
llvm/include/llvm/ADT/DenseMapInfo.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
index 3d83a2c1473f5..a5ef92c478552 100644
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -142,7 +142,7 @@ template<> struct DenseMapInfo<unsigned long> {
if constexpr (sizeof(Val) == 4)
return DenseMapInfo<unsigned>::getHashValue(Val);
else
- return detail::combineHashValue(Val >> (4 * sizeof(Val)), Val);
+ return densemap::detail::mix(Val);
}
static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
>From ffa04f0b5295524188063ef9fbaf1c4f755a4ab7 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Thu, 20 Jun 2024 13:05:10 +0100
Subject: [PATCH 3/3] Use densemap::detail::mix(Val) for the unsigned long long
case as well
---
llvm/include/llvm/ADT/DenseMapInfo.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/include/llvm/ADT/DenseMapInfo.h b/llvm/include/llvm/ADT/DenseMapInfo.h
index a5ef92c478552..07c37e353a40b 100644
--- a/llvm/include/llvm/ADT/DenseMapInfo.h
+++ b/llvm/include/llvm/ADT/DenseMapInfo.h
@@ -156,7 +156,7 @@ template<> struct DenseMapInfo<unsigned long long> {
static inline unsigned long long getTombstoneKey() { return ~0ULL - 1ULL; }
static unsigned getHashValue(const unsigned long long& Val) {
- return detail::combineHashValue(Val >> 32, Val);
+ return densemap::detail::mix(Val);
}
static bool isEqual(const unsigned long long& LHS,
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