melver created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
- Avoid bit operations to compute Offset by removing bitfields. On 64-bit
architectures, SLocEntry's size is unchanged.
- Provide branch-prediction hints to compiler to generate better code.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D80428
Files:
clang/include/clang/Basic/SourceManager.h
clang/lib/Basic/SourceManager.cpp
Index: clang/lib/Basic/SourceManager.cpp
===================================================================
--- clang/lib/Basic/SourceManager.cpp
+++ clang/lib/Basic/SourceManager.cpp
@@ -885,14 +885,14 @@
bool Invalid = false;
unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
unsigned MidOffset = getLocalSLocEntry(MiddleIndex, &Invalid).getOffset();
- if (Invalid)
+ if (LLVM_UNLIKELY(Invalid))
return FileID::get(0);
++NumProbes;
// If the offset of the midpoint is too large, chop the high side of the
// range to the midpoint.
- if (MidOffset > SLocOffset) {
+ if (LLVM_LIKELY(MidOffset > SLocOffset)) {
GreaterIndex = MiddleIndex;
continue;
}
Index: clang/include/clang/Basic/SourceManager.h
===================================================================
--- clang/include/clang/Basic/SourceManager.h
+++ clang/include/clang/Basic/SourceManager.h
@@ -439,8 +439,8 @@
/// SourceManager keeps an array of these objects, and they are uniquely
/// identified by the FileID datatype.
class SLocEntry {
- unsigned Offset : 31;
- unsigned IsExpansion : 1;
+ unsigned Offset;
+ bool IsExpansion;
union {
FileInfo File;
ExpansionInfo Expansion;
@@ -465,7 +465,6 @@
}
static SLocEntry get(unsigned Offset, const FileInfo &FI) {
- assert(!(Offset & (1u << 31)) && "Offset is too large");
SLocEntry E;
E.Offset = Offset;
E.IsExpansion = false;
@@ -474,7 +473,6 @@
}
static SLocEntry get(unsigned Offset, const ExpansionInfo &Expansion) {
- assert(!(Offset & (1u << 31)) && "Offset is too large");
SLocEntry E;
E.Offset = Offset;
E.IsExpansion = true;
Index: clang/lib/Basic/SourceManager.cpp
===================================================================
--- clang/lib/Basic/SourceManager.cpp
+++ clang/lib/Basic/SourceManager.cpp
@@ -885,14 +885,14 @@
bool Invalid = false;
unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
unsigned MidOffset = getLocalSLocEntry(MiddleIndex, &Invalid).getOffset();
- if (Invalid)
+ if (LLVM_UNLIKELY(Invalid))
return FileID::get(0);
++NumProbes;
// If the offset of the midpoint is too large, chop the high side of the
// range to the midpoint.
- if (MidOffset > SLocOffset) {
+ if (LLVM_LIKELY(MidOffset > SLocOffset)) {
GreaterIndex = MiddleIndex;
continue;
}
Index: clang/include/clang/Basic/SourceManager.h
===================================================================
--- clang/include/clang/Basic/SourceManager.h
+++ clang/include/clang/Basic/SourceManager.h
@@ -439,8 +439,8 @@
/// SourceManager keeps an array of these objects, and they are uniquely
/// identified by the FileID datatype.
class SLocEntry {
- unsigned Offset : 31;
- unsigned IsExpansion : 1;
+ unsigned Offset;
+ bool IsExpansion;
union {
FileInfo File;
ExpansionInfo Expansion;
@@ -465,7 +465,6 @@
}
static SLocEntry get(unsigned Offset, const FileInfo &FI) {
- assert(!(Offset & (1u << 31)) && "Offset is too large");
SLocEntry E;
E.Offset = Offset;
E.IsExpansion = false;
@@ -474,7 +473,6 @@
}
static SLocEntry get(unsigned Offset, const ExpansionInfo &Expansion) {
- assert(!(Offset & (1u << 31)) && "Offset is too large");
SLocEntry E;
E.Offset = Offset;
E.IsExpansion = true;
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