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Differential D26372

[COFF] Don't round alignment if it's already a power-of-two
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Authored by davide on Nov 7 2016, 3:01 PM.

Details

Reviewers
ruiu
Commits
rGc520e18ce067: [lld/COFF] Don't round alignment if it's already a power-of-two.
rLLD286553: [lld/COFF] Don't round alignment if it's already a power-of-two.
rL286553: [lld/COFF] Don't round alignment if it's already a power-of-two.
Summary

This seems to match what link.exe does.

Diff Detail

Repository
rL LLVM

Event Timeline

davide updated this revision to Diff 77107.Nov 7 2016, 3:01 PM
davide retitled this revision from to [COFF] Don't round alignment if it's already a power-of-two.
davide updated this object.
davide added a reviewer: ruiu.
davide added a subscriber: llvm-commits.
ruiu edited edge metadata.Nov 10 2016, 6:32 PM

LGTM with using PowerOf2Ceil.

ruiu accepted this revision.Nov 10 2016, 6:32 PM
ruiu edited edge metadata.
This revision is now accepted and ready to land.Nov 10 2016, 6:32 PM
Closed by commit rL286553: [lld/COFF] Don't round alignment if it's already a power-of-two. (authored by davide). · Explain WhyNov 10 2016, 7:03 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
lld/
trunk/
COFF/
2 lines
test/
COFF/
2 lines

Diff 77590

lld/trunk/COFF/Chunks.cpp

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void SectionChunk::replace(SectionChunk *Other) { void SectionChunk::replace(SectionChunk *Other) {
Other->Repl = Repl; Other->Repl = Repl;
Other->Live = false; Other->Live = false;
} }
CommonChunk::CommonChunk(const COFFSymbolRef S) : Sym(S) { CommonChunk::CommonChunk(const COFFSymbolRef S) : Sym(S) {
// Common symbols are aligned on natural boundaries up to 32 bytes. // Common symbols are aligned on natural boundaries up to 32 bytes.
// This is what MSVC link.exe does. // This is what MSVC link.exe does.
Align = std::min(uint64_t(32), NextPowerOf2(Sym.getValue())); Align = std::min(uint64_t(32), PowerOf2Ceil(Sym.getValue()));
} }
uint32_t CommonChunk::getPermissions() const { uint32_t CommonChunk::getPermissions() const {
return IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | return IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ |
IMAGE_SCN_MEM_WRITE; IMAGE_SCN_MEM_WRITE;
} }
void StringChunk::writeTo(uint8_t *Buf) const { void StringChunk::writeTo(uint8_t *Buf) const {
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lld/trunk/test/COFF/common.test

# RUN: yaml2obj %s > %t.obj # RUN: yaml2obj %s > %t.obj
# RUN: lld-link /out:%t.exe /entry:main %t.obj %t.obj # RUN: lld-link /out:%t.exe /entry:main %t.obj %t.obj
# RUN: llvm-objdump -d %t.exe | FileCheck %s # RUN: llvm-objdump -d %t.exe | FileCheck %s
# Operands of B8 (MOV EAX) are common symbols # Operands of B8 (MOV EAX) are common symbols
# CHECK: 3000: b8 00 10 00 40 # CHECK: 3000: b8 00 10 00 40
# CHECK: 3005: b8 04 10 00 40 # CHECK: 3005: b8 04 10 00 40
# CHECK: 300a: b8 20 10 00 40 # CHECK: 300a: b8 20 10 00 40
# CHECK: 300f: b8 60 10 00 40 # CHECK: 300f: b8 60 10 00 40
# CHECK: 3014: b8 80 10 00 40 # CHECK: 3014: b8 70 10 00 40
--- !COFF --- !COFF
header: header:
Machine: IMAGE_FILE_MACHINE_AMD64 Machine: IMAGE_FILE_MACHINE_AMD64
Characteristics: [] Characteristics: []
sections: sections:
- Name: .text - Name: .text
Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ] Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
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