[llvm] [BasicBlockSections] Split cold parts of custom-section functions. (PR #66731)
Rahman Lavaee via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 22 13:47:16 PDT 2023
https://github.com/rlavaee updated https://github.com/llvm/llvm-project/pull/66731
>From d4af4fdc27685ad9093a47b4721c4a4b6a7723ea Mon Sep 17 00:00:00 2001
From: Rahman Lavaee <rahmanl at google.com>
Date: Tue, 19 Sep 2023 00:09:54 +0000
Subject: [PATCH 1/4] [BasicBlockSections] Split cold parts of custom-section
functions.
This PR makes `-basic-block-sections` handle functions with custom
non-dot-text sections correctly. Cold parts of such functions must
be placed in the same section (not in `.text.split`) but with a
unique id.
---
.../CodeGen/TargetLoweringObjectFileImpl.cpp | 18 +++++++----
.../basic-block-sections-pragma-sections.ll | 30 +++++++++++++------
2 files changed, 34 insertions(+), 14 deletions(-)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 622c8addc548f4f..05d035dc697936b 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1038,14 +1038,21 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
// under the .text.eh prefix. For regular sections, we either use a unique
// name, or a unique ID for the section.
SmallString<128> Name;
- if (MBB.getSectionID() == MBBSectionID::ColdSectionID) {
- Name += BBSectionsColdTextPrefix;
- Name += MBB.getParent()->getName();
+ StringRef FunctionSectionName = MBB.getParent()->getSection()->getName();
+ if (!FunctionSectionName.equals(".text") && !FunctionSectionName.startswith(".text.")) {
+ // If the original function has a custom non-dot-text section, then split the cold part into that section too, but with a unique id.
+ Name = FunctionSectionName;
+ UniqueID = NextUniqueID++;
+ } else {
+ StringRef FunctionName = MBB.getParent()->getName();
+ if (MBB.getSectionID() == MBBSectionID::ColdSectionID){
+ Name += BBSectionsColdTextPrefix;
+ Name += FunctionName;
} else if (MBB.getSectionID() == MBBSectionID::ExceptionSectionID) {
Name += ".text.eh.";
- Name += MBB.getParent()->getName();
+ Name += FunctionName;
} else {
- Name += MBB.getParent()->getSection()->getName();
+ Name += FunctionSectionName;
if (TM.getUniqueBasicBlockSectionNames()) {
if (!Name.endswith("."))
Name += ".";
@@ -1054,6 +1061,7 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
UniqueID = NextUniqueID++;
}
}
+ }
unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_EXECINSTR;
std::string GroupName;
diff --git a/llvm/test/CodeGen/X86/basic-block-sections-pragma-sections.ll b/llvm/test/CodeGen/X86/basic-block-sections-pragma-sections.ll
index d63fbdd7b362e07..13a4607100a057a 100644
--- a/llvm/test/CodeGen/X86/basic-block-sections-pragma-sections.ll
+++ b/llvm/test/CodeGen/X86/basic-block-sections-pragma-sections.ll
@@ -1,9 +1,15 @@
+;; Tests for basic block sections applied on a function in a custom section.
; RUN: llc < %s -mtriple=x86_64-pc-linux -basic-block-sections=all | FileCheck %s
; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections -basic-block-sections=all | FileCheck %s
-; RUN: echo "!_Z3fooi" > %t.list.txt
-; RUN: echo "!!2" >> %t.list.txt
-; RUN: llc < %s -mtriple=x86_64-pc-linux -basic-block-sections=%t.list.txt | FileCheck %s --check-prefix=LIST
-; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections -basic-block-sections=%t.list.txt | FileCheck %s --check-prefix=LIST
+; RUN: echo "!_Z3fooi" > %t1.list.txt
+; RUN: echo "!!2" >> %t1.list.txt
+; RUN: llc < %s -mtriple=x86_64-pc-linux -basic-block-sections=%t1.list.txt | FileCheck %s --check-prefix=LIST1
+; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections -basic-block-sections=%t1.list.txt | FileCheck %s --check-prefix=LIST1
+; RUN: echo "!_Z3fooi" > %t2.list.txt
+; RUN: echo "!!0" >> %t2.list.txt
+; RUN: llc < %s -mtriple=x86_64-pc-linux -basic-block-sections=%t2.list.txt | FileCheck %s --check-prefix=LIST2
+; RUN: llc < %s -mtriple=x86_64-pc-linux -function-sections -basic-block-sections=%t2.list.txt | FileCheck %s --check-prefix=LIST2
+
; CHECK: .section foo_section,"ax", at progbits,unique,1
; CHECK-LABEL: _Z3fooi:
@@ -12,11 +18,17 @@
; CHECK: .section foo_section,"ax", at progbits,unique,3
; CHECK-NEXT: _Z3fooi.__part.2:
-; LIST: .section foo_section,"ax", at progbits,unique,1
-; LIST-LABEL: _Z3fooi:
-; LIST: .section foo_section,"ax", at progbits,unique,2
-; LIST-NEXT: _Z3fooi.__part.0:
-; LIST-NOT: .section foo_section,"ax", at progbits,unique,3
+; LIST1: .section foo_section,"ax", at progbits,unique,1
+; LIST1-LABEL: _Z3fooi:
+; LIST1: .section foo_section,"ax", at progbits,unique,2
+; LIST1-NEXT: _Z3fooi.__part.0:
+; LIST1-NOT: .section foo_section,"ax", at progbits,unique,3
+
+; LIST2: .section foo_section,"ax", at progbits,unique,1
+; LIST2-LABEL: _Z3fooi:
+; LIST2: .section foo_section,"ax", at progbits,unique,2
+; LIST2-NEXT: _Z3fooi.cold:
+; LIST2-NOT: .section foo_section,"ax", at progbits,unique,3
;; Source to generate the IR:
;; #pragma clang section text = "foo_section"
>From 88a8f72c1f2b0967155d74f0b9d60dfd61614b38 Mon Sep 17 00:00:00 2001
From: Rahman Lavaee <rahmanl at google.com>
Date: Tue, 19 Sep 2023 02:57:46 +0000
Subject: [PATCH 2/4] clang-format.
---
.../CodeGen/TargetLoweringObjectFileImpl.cpp | 32 ++++++++++---------
1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 05d035dc697936b..b38ddd075c2fd48 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1039,29 +1039,31 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
// name, or a unique ID for the section.
SmallString<128> Name;
StringRef FunctionSectionName = MBB.getParent()->getSection()->getName();
- if (!FunctionSectionName.equals(".text") && !FunctionSectionName.startswith(".text.")) {
- // If the original function has a custom non-dot-text section, then split the cold part into that section too, but with a unique id.
+ if (!FunctionSectionName.equals(".text") &&
+ !FunctionSectionName.startswith(".text.")) {
+ // If the original function has a custom non-dot-text section, then split
+ // the cold part into that section too, but with a unique id.
Name = FunctionSectionName;
UniqueID = NextUniqueID++;
} else {
- StringRef FunctionName = MBB.getParent()->getName();
- if (MBB.getSectionID() == MBBSectionID::ColdSectionID){
+ StringRef FunctionName = MBB.getParent()->getName();
+ if (MBB.getSectionID() == MBBSectionID::ColdSectionID) {
Name += BBSectionsColdTextPrefix;
Name += FunctionName;
- } else if (MBB.getSectionID() == MBBSectionID::ExceptionSectionID) {
- Name += ".text.eh.";
- Name += FunctionName;
- } else {
- Name += FunctionSectionName;
- if (TM.getUniqueBasicBlockSectionNames()) {
- if (!Name.endswith("."))
- Name += ".";
- Name += MBB.getSymbol()->getName();
+ } else if (MBB.getSectionID() == MBBSectionID::ExceptionSectionID) {
+ Name += ".text.eh.";
+ Name += FunctionName;
} else {
- UniqueID = NextUniqueID++;
+ Name += FunctionSectionName;
+ if (TM.getUniqueBasicBlockSectionNames()) {
+ if (!Name.endswith("."))
+ Name += ".";
+ Name += MBB.getSymbol()->getName();
+ } else {
+ UniqueID = NextUniqueID++;
+ }
}
}
- }
unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_EXECINSTR;
std::string GroupName;
>From 1430099025b81a9a0f20f8e550e4bb00c45862d7 Mon Sep 17 00:00:00 2001
From: Rahman Lavaee <rahmanl at google.com>
Date: Tue, 19 Sep 2023 03:00:29 +0000
Subject: [PATCH 3/4] clang-format.
---
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index b38ddd075c2fd48..ecbeb335d1e02e8 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1041,8 +1041,8 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
StringRef FunctionSectionName = MBB.getParent()->getSection()->getName();
if (!FunctionSectionName.equals(".text") &&
!FunctionSectionName.startswith(".text.")) {
- // If the original function has a custom non-dot-text section, then split
- // the cold part into that section too, but with a unique id.
+ // If the original function has a custom non-dot-text section, then emit
+ // all basic block sections into that section too, but with a unique id.
Name = FunctionSectionName;
UniqueID = NextUniqueID++;
} else {
>From 87ffbe92b212b604ecd2a51caf9fdccdc13f99aa Mon Sep 17 00:00:00 2001
From: Rahman Lavaee <rahmanl at google.com>
Date: Tue, 19 Sep 2023 17:56:04 +0000
Subject: [PATCH 4/4] Address comment.
---
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index ecbeb335d1e02e8..6210e7fc128a30c 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1039,13 +1039,9 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
// name, or a unique ID for the section.
SmallString<128> Name;
StringRef FunctionSectionName = MBB.getParent()->getSection()->getName();
- if (!FunctionSectionName.equals(".text") &&
- !FunctionSectionName.startswith(".text.")) {
- // If the original function has a custom non-dot-text section, then emit
- // all basic block sections into that section too, but with a unique id.
- Name = FunctionSectionName;
- UniqueID = NextUniqueID++;
- } else {
+ if (FunctionSectionName.equals(".text") ||
+ FunctionSectionName.startswith(".text.")) {
+ // Function is in a regular .text section.
StringRef FunctionName = MBB.getParent()->getName();
if (MBB.getSectionID() == MBBSectionID::ColdSectionID) {
Name += BBSectionsColdTextPrefix;
@@ -1063,6 +1059,11 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
UniqueID = NextUniqueID++;
}
}
+ } else {
+ // If the original function has a custom non-dot-text section, then emit
+ // all basic block sections into that section too, each with a unique id.
+ Name = FunctionSectionName;
+ UniqueID = NextUniqueID++;
}
unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_EXECINSTR;
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