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Merged
merged 14 commits into from
Apr 25, 2024
Merged

[RISCV] Support RISCV Atomics ABI attributes #84597

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7147849
[𝘀𝗽𝗿] initial version
ilovepi Mar 9, 2024
2b14f06
Fix formatting
ilovepi Mar 9, 2024
bc7196f
Remove code from SCS PR
ilovepi Mar 9, 2024
87d6966
remove debugging statements
ilovepi Mar 9, 2024
d08e85d
Remove unrelated code
ilovepi Mar 9, 2024
9a7fae0
Pass iterator instead of repeating lookup
ilovepi Mar 11, 2024
1691a7c
Fix whitespace
ilovepi Mar 11, 2024
838ebcd
Update tests and fix whitespace
ilovepi Mar 15, 2024
d25c54f
Add NEXT to CHECK lines in test
ilovepi Mar 22, 2024
a59de4d
Split out change of defaults into separate patch
ilovepi Apr 2, 2024
ab7a2b3
Improve testing
ilovepi Apr 2, 2024
9097db9
update commit message
ilovepi Apr 4, 2024
6cddfbe
Fix naming in test cases for consistency
ilovepi Apr 4, 2024
9ac2d5b
clang-format
ilovepi Apr 4, 2024
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63 changes: 63 additions & 0 deletions lld/ELF/Arch/RISCV.cpp
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Expand Up @@ -1084,10 +1084,62 @@ static void mergeArch(RISCVISAInfo::OrderedExtensionMap &mergedExts,
}
}

static void mergeAtomic(DenseMap<unsigned, unsigned>::iterator it,
const InputSectionBase *oldSection,
const InputSectionBase *newSection, unsigned int oldTag,
unsigned int newTag) {
using RISCVAttrs::RISCVAtomicAbiTag::AtomicABI;
// Same tags stay the same, and UNKNOWN is compatible with anything
if (oldTag == newTag || newTag == AtomicABI::UNKNOWN)
return;

switch (oldTag) {
case AtomicABI::UNKNOWN:
it->getSecond() = newTag;
return;
case AtomicABI::A6C:
switch (newTag) {
case AtomicABI::A6S:
it->getSecond() = AtomicABI::A6C;
return;
case AtomicABI::A7:
error(toString(oldSection) + " has atomic_abi=" + Twine(oldTag) +
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This should use errorOrWarn.

Sorry that I did not follow up the discussion in time, but I'd appreciate that I had the opportunity to give this comment after the patch was approved by @asb ...

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Noted. I'll follow up in #90266. I based this on your comment to a similar line in #84598 (comment), but it seems like I misunderstood?

" but " + toString(newSection) +
" has atomic_abi=" + Twine(newTag));
return;
};

case AtomicABI::A6S:
switch (newTag) {
case AtomicABI::A6C:
it->getSecond() = AtomicABI::A6C;
return;
case AtomicABI::A7:
it->getSecond() = AtomicABI::A7;
return;
};

case AtomicABI::A7:
switch (newTag) {
case AtomicABI::A6S:
it->getSecond() = AtomicABI::A7;
return;
case AtomicABI::A6C:
error(toString(oldSection) + " has atomic_abi=" + Twine(oldTag) +
" but " + toString(newSection) +
" has atomic_abi=" + Twine(newTag));
return;
};
default:
llvm_unreachable("unknown AtomicABI");
};
}

static RISCVAttributesSection *
mergeAttributesSection(const SmallVector<InputSectionBase *, 0> &sections) {
RISCVISAInfo::OrderedExtensionMap exts;
const InputSectionBase *firstStackAlign = nullptr;
const InputSectionBase *firstAtomicAbi = nullptr;
unsigned firstStackAlignValue = 0, xlen = 0;
bool hasArch = false;

Expand Down Expand Up @@ -1134,6 +1186,17 @@ mergeAttributesSection(const SmallVector<InputSectionBase *, 0> &sections) {
case RISCVAttrs::PRIV_SPEC_MINOR:
case RISCVAttrs::PRIV_SPEC_REVISION:
break;

case llvm::RISCVAttrs::AttrType::ATOMIC_ABI:
if (auto i = parser.getAttributeValue(tag.attr)) {
auto r = merged.intAttr.try_emplace(tag.attr, *i);
if (r.second) {
firstAtomicAbi = sec;
} else {
mergeAtomic(r.first, firstAtomicAbi, sec, r.first->getSecond(), *i);
}
}
continue;
}

// Fallback for deprecated priv_spec* and other unknown attributes: retain
Expand Down
202 changes: 202 additions & 0 deletions lld/test/ELF/riscv-attributes.s
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Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,39 @@
# RUN: not ld.lld a.o b.o c.o diff_stack_align.o -o /dev/null 2>&1 | FileCheck %s --check-prefix=STACK_ALIGN --implicit-check-not=error:
# STACK_ALIGN: error: diff_stack_align.o:(.riscv.attributes) has stack_align=32 but a.o:(.riscv.attributes) has stack_align=16

## merging atomic_abi values for A6C and A7 lead to an error.
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Mismatched

Upper case. And there is a better word than "merging"

# RUN: llvm-mc -filetype=obj -triple=riscv64 atomic_abi_A6C.s -o atomic_abi_A6C.o
# RUN: llvm-mc -filetype=obj -triple=riscv64 atomic_abi_A7.s -o atomic_abi_A7.o
# RUN: not ld.lld atomic_abi_A6C.o atomic_abi_A7.o -o /dev/null 2>&1 | FileCheck %s --check-prefix=ATOMIC_ABI_ERROR --implicit-check-not=error:
# ATOMIC_ABI_ERROR: error: atomic_abi_A6C.o:(.riscv.attributes) has atomic_abi=1 but atomic_abi_A7.o:(.riscv.attributes) has atomic_abi=3

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We don't use double blank lines


# RUN: llvm-mc -filetype=obj -triple=riscv64 atomic_abi_A6S.s -o atomic_abi_A6S.o
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excess space

# RUN: ld.lld atomic_abi_A6S.o atomic_abi_A6C.o -o atomic_abi_A6C_A6S
# RUN: llvm-readobj -A atomic_abi_A6C_A6S | FileCheck %s --check-prefix=A6C_A6S

# RUN: ld.lld atomic_abi_A6S.o atomic_abi_A7.o -o atomic_abi_A6S_A7
# RUN: llvm-readobj -A atomic_abi_A6S_A7 | FileCheck %s --check-prefix=A6S_A7

# RUN: llvm-mc -filetype=obj -triple=riscv64 atomic_abi_unknown.s -o atomic_abi_unknown.o
# RUN: ld.lld atomic_abi_unknown.o atomic_abi_A6C.o -o atomic_abi_A6C_unknown
# RUN: llvm-readobj -A atomic_abi_A6C_unknown | FileCheck %s --check-prefixes=UNKNOWN_A6C

# RUN: ld.lld atomic_abi_unknown.o diff_stack_align.o -o atomic_abi_none_unknown
# RUN: llvm-readobj -A atomic_abi_none_unknown | FileCheck %s --check-prefixes=UNKNOWN_NONE

# RUN: ld.lld diff_stack_align.o atomic_abi_A6C.o -o atomic_abi_A6C_none
# RUN: llvm-readobj -A atomic_abi_A6C_none | FileCheck %s --check-prefixes=NONE_A6C

# RUN: ld.lld atomic_abi_unknown.o atomic_abi_A6S.o -o atomic_abi_A6S_unknown
# RUN: llvm-readobj -A atomic_abi_A6S_unknown | FileCheck %s --check-prefix=UNKNOWN_A6S

# RUN: ld.lld atomic_abi_unknown.o atomic_abi_A7.o -o atomic_abi_A7_unknown
# RUN: llvm-readobj -A atomic_abi_A7_unknown | FileCheck %s --check-prefix=UNKNOWN_A7

# RUN: ld.lld diff_stack_align.o atomic_abi_A7.o -o atomic_abi_A7_none
# RUN: llvm-readobj -A atomic_abi_A7_none | FileCheck %s --check-prefix=NONE_A7

## The deprecated priv_spec is not handled as GNU ld does.
## Differing priv_spec attributes lead to an absent attribute.
# RUN: llvm-mc -filetype=obj -triple=riscv64 diff_priv_spec.s -o diff_priv_spec.o
Expand Down Expand Up @@ -286,6 +319,175 @@
.attribute priv_spec, 3
.attribute priv_spec_minor, 3

#--- atomic_abi_unknown.s
.attribute atomic_abi, 0

#--- atomic_abi_A6C.s
.attribute atomic_abi, 1

#--- atomic_abi_A6S.s
.attribute atomic_abi, 2

#--- atomic_abi_A7.s
.attribute atomic_abi, 3

# UNKNOWN_NONE: BuildAttributes {
# UNKNOWN_NONE-NEXT: FormatVersion: 0x41
# UNKNOWN_NONE-NEXT: Section 1 {
# UNKNOWN_NONE-NEXT: SectionLength: 17
# UNKNOWN_NONE-NEXT: Vendor: riscv
# UNKNOWN_NONE-NEXT: Tag: Tag_File (0x1)
# UNKNOWN_NONE-NEXT: Size: 7
# UNKNOWN_NONE-NEXT: FileAttributes {
# UNKNOWN_NONE-NEXT: Attribute {
# UNKNOWN_NONE-NEXT: Tag: 4
# UNKNOWN_NONE-NEXT: Value: 32
# UNKNOWN_NONE-NEXT: TagName: stack_align
# UNKNOWN_NONE-NEXT: Description: Stack alignment is 32-bytes
# UNKNOWN_NONE-NEXT: }
# UNKNOWN_NONE-NEXT: }
# UNKNOWN_NONE-NEXT: }
# UNKNOWN_NONE-NEXT: }

# NONE_A6C: BuildAttributes {
# NONE_A6C-NEXT: FormatVersion: 0x41
# NONE_A6C-NEXT: Section 1 {
# NONE_A6C-NEXT: SectionLength: 19
# NONE_A6C-NEXT: Vendor: riscv
# NONE_A6C-NEXT: Tag: Tag_File (0x1)
# NONE_A6C-NEXT: Size: 9
# NONE_A6C-NEXT: FileAttributes {
# NONE_A6C-NEXT: Attribute {
# NONE_A6C-NEXT: Tag: 14
# NONE_A6C-NEXT: Value: 1
# NONE_A6C-NEXT: TagName: atomic_abi
# NONE_A6C-NEXT: Description: Atomic ABI is 1
# NONE_A6C-NEXT: }
# NONE_A6C-NEXT: Attribute {
# NONE_A6C-NEXT: Tag: 4
# NONE_A6C-NEXT: Value: 32
# NONE_A6C-NEXT: TagName: stack_align
# NONE_A6C-NEXT: Description: Stack alignment is 32-bytes
# NONE_A6C-NEXT: }
# NONE_A6C-NEXT: }
# NONE_A6C-NEXT: }
# NONE_A6C-NEXT: }

# UNKNOWN_A6C: BuildAttributes {
# UNKNOWN_A6C-NEXT: FormatVersion: 0x41
# UNKNOWN_A6C-NEXT: Section 1 {
# UNKNOWN_A6C-NEXT: SectionLength: 17
# UNKNOWN_A6C-NEXT: Vendor: riscv
# UNKNOWN_A6C-NEXT: Tag: Tag_File (0x1)
# UNKNOWN_A6C-NEXT: Size: 7
# UNKNOWN_A6C-NEXT: FileAttributes {
# UNKNOWN_A6C-NEXT: Attribute {
# UNKNOWN_A6C-NEXT: Tag: 14
# UNKNOWN_A6C-NEXT: Value: 1
# UNKNOWN_A6C-NEXT: TagName: atomic_abi
# UNKNOWN_A6C-NEXT: Description: Atomic ABI is 1
# UNKNOWN_A6C-NEXT: }
# UNKNOWN_A6C-NEXT: }
# UNKNOWN_A6C-NEXT: }
# UNKNOWN_A6C-NEXT: }

# UNKNOWN_A6S: BuildAttributes {
# UNKNOWN_A6S-NEXT: FormatVersion: 0x41
# UNKNOWN_A6S-NEXT: Section 1 {
# UNKNOWN_A6S-NEXT: SectionLength:
# UNKNOWN_A6S-NEXT: Vendor: riscv
# UNKNOWN_A6S-NEXT: Tag: Tag_File (0x1)
# UNKNOWN_A6S-NEXT: Size: 7
# UNKNOWN_A6S-NEXT: FileAttributes {
# UNKNOWN_A6S-NEXT: Attribute {
# UNKNOWN_A6S-NEXT: Tag: 14
# UNKNOWN_A6S-NEXT: Value: 2
# UNKNOWN_A6S-NEXT: TagName: atomic_abi
# UNKNOWN_A6S-NEXT: Description: Atomic ABI is 2
# UNKNOWN_A6S-NEXT: }
# UNKNOWN_A6S-NEXT: }
# UNKNOWN_A6S-NEXT: }
# UNKNOWN_A6S-NEXT: }

# NONE_A7: BuildAttributes {
# NONE_A7-NEXT: FormatVersion: 0x41
# NONE_A7-NEXT: Section 1 {
# NONE_A7-NEXT: SectionLength: 19
# NONE_A7-NEXT: Vendor: riscv
# NONE_A7-NEXT: Tag: Tag_File (0x1)
# NONE_A7-NEXT: Size: 9
# NONE_A7-NEXT: FileAttributes {
# NONE_A7-NEXT: Attribute {
# NONE_A7-NEXT: Tag: 14
# NONE_A7-NEXT: Value: 3
# NONE_A7-NEXT: TagName: atomic_abi
# NONE_A7-NEXT: Description: Atomic ABI is 3
# NONE_A7-NEXT: }
# NONE_A7-NEXT: Attribute {
# NONE_A7-NEXT: Tag: 4
# NONE_A7-NEXT: Value: 32
# NONE_A7-NEXT: TagName: stack_align
# NONE_A7-NEXT: Description: Stack alignment is 32-bytes
# NONE_A7-NEXT: }
# NONE_A7-NEXT: }
# NONE_A7-NEXT: }
# NONE_A7-NEXT: }


# UNKNOWN_A7: BuildAttributes {
# UNKNOWN_A7-NEXT: FormatVersion: 0x41
# UNKNOWN_A7-NEXT: Section 1 {
# UNKNOWN_A7-NEXT: SectionLength: 17
# UNKNOWN_A7-NEXT: Vendor: riscv
# UNKNOWN_A7-NEXT: Tag: Tag_File (0x1)
# UNKNOWN_A7-NEXT: Size: 7
# UNKNOWN_A7-NEXT: FileAttributes {
# UNKNOWN_A7-NEXT: Attribute {
# UNKNOWN_A7-NEXT: Tag: 14
# UNKNOWN_A7-NEXT: Value: 3
# UNKNOWN_A7-NEXT: TagName: atomic_abi
# UNKNOWN_A7-NEXT: Description: Atomic ABI is 3
# UNKNOWN_A7-NEXT: }
# UNKNOWN_A7-NEXT: }
# UNKNOWN_A7-NEXT: }
# UNKNOWN_A7-NEXT: }

# A6C_A6S: BuildAttributes {
# A6C_A6S-NEXT: FormatVersion: 0x41
# A6C_A6S-NEXT: Section 1 {
# A6C_A6S-NEXT: SectionLength: 17
# A6C_A6S-NEXT: Vendor: riscv
# A6C_A6S-NEXT: Tag: Tag_File (0x1)
# A6C_A6S-NEXT: Size: 7
# A6C_A6S-NEXT: FileAttributes {
# A6C_A6S-NEXT: Attribute {
# A6C_A6S-NEXT: Tag: 14
# A6C_A6S-NEXT: Value: 1
# A6C_A6S-NEXT: TagName: atomic_abi
# A6C_A6S-NEXT: Description: Atomic ABI is 1
# A6C_A6S-NEXT: }
# A6C_A6S-NEXT: }
# A6C_A6S-NEXT: }
# A6C_A6S-NEXT: }

# A6S_A7: BuildAttributes {
# A6S_A7-NEXT: FormatVersion: 0x41
# A6S_A7-NEXT: Section 1 {
# A6S_A7-NEXT: SectionLength: 17
# A6S_A7-NEXT: Vendor: riscv
# A6S_A7-NEXT: Tag: Tag_File (0x1)
# A6S_A7-NEXT: Size: 7
# A6S_A7-NEXT: FileAttributes {
# A6S_A7-NEXT: Attribute {
# A6S_A7-NEXT: Tag: 14
# A6S_A7-NEXT: Value: 3
# A6S_A7-NEXT: TagName: atomic_abi
# A6S_A7-NEXT: Description: Atomic ABI is 3
# A6S_A7-NEXT: }
# A6S_A7-NEXT: }
# A6S_A7-NEXT: }
# A6S_A7-NEXT: }

#--- unknown13.s
.attribute 13, "0"
#--- unknown13a.s
Expand Down
1 change: 1 addition & 0 deletions llvm/include/llvm/Support/RISCVAttributeParser.h
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Expand Up @@ -24,6 +24,7 @@ class RISCVAttributeParser : public ELFAttributeParser {

Error unalignedAccess(unsigned tag);
Error stackAlign(unsigned tag);
Error atomicAbi(unsigned tag);

public:
RISCVAttributeParser(ScopedPrinter *sw)
Expand Down
13 changes: 13 additions & 0 deletions llvm/include/llvm/Support/RISCVAttributes.h
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Expand Up @@ -32,8 +32,21 @@ enum AttrType : unsigned {
PRIV_SPEC = 8,
PRIV_SPEC_MINOR = 10,
PRIV_SPEC_REVISION = 12,
ATOMIC_ABI = 14,
};

namespace RISCVAtomicAbiTag {
enum AtomicABI : unsigned {
// Values for Tag_RISCV_atomic_abi
// Defined at
// https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc#tag_riscv_atomic_abi-14-uleb128version
UNKNOWN = 0,
A6C = 1,
A6S = 2,
A7 = 3,
};
} // namespace RISCVAtomicAbiTag

enum { NOT_ALLOWED = 0, ALLOWED = 1 };

} // namespace RISCVAttrs
Expand Down
13 changes: 12 additions & 1 deletion llvm/lib/Support/RISCVAttributeParser.cpp
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Expand Up @@ -36,7 +36,18 @@ const RISCVAttributeParser::DisplayHandler
{
RISCVAttrs::UNALIGNED_ACCESS,
&RISCVAttributeParser::unalignedAccess,
}};
},
{
RISCVAttrs::ATOMIC_ABI,
&RISCVAttributeParser::atomicAbi,
},
};

Error RISCVAttributeParser::atomicAbi(unsigned Tag) {
uint64_t Value = de.getULEB128(cursor);
printAttribute(Tag, Value, "Atomic ABI is " + utostr(Value));
return Error::success();
}

Error RISCVAttributeParser::unalignedAccess(unsigned tag) {
static const char *strings[] = {"No unaligned access", "Unaligned access"};
Expand Down
1 change: 1 addition & 0 deletions llvm/lib/Support/RISCVAttributes.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ static constexpr TagNameItem tagData[] = {
{PRIV_SPEC, "Tag_priv_spec"},
{PRIV_SPEC_MINOR, "Tag_priv_spec_minor"},
{PRIV_SPEC_REVISION, "Tag_priv_spec_revision"},
{ATOMIC_ABI, "Tag_atomic_abi"},
};

constexpr TagNameMap RISCVAttributeTags{tagData};
Expand Down
7 changes: 7 additions & 0 deletions llvm/lib/Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,13 @@ void RISCVTargetStreamer::emitTargetAttributes(const MCSubtargetInfo &STI,
auto &ISAInfo = *ParseResult;
emitTextAttribute(RISCVAttrs::ARCH, ISAInfo->toString());
}

if (STI.hasFeature(RISCV::FeatureStdExtA)) {
unsigned AtomicABITag = STI.hasFeature(RISCV::FeatureTrailingSeqCstFence)
? RISCVAttrs::RISCVAtomicAbiTag::AtomicABI::A6S
: RISCVAttrs::RISCVAtomicAbiTag::AtomicABI::A6C;
emitAttribute(RISCVAttrs::ATOMIC_ABI, AtomicABITag);
}
}

// This part is for ascii assembly output
Expand Down
10 changes: 9 additions & 1 deletion llvm/test/CodeGen/RISCV/attributes.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -128,7 +128,8 @@
; RUN: llc -mtriple=riscv64 -mattr=+m %s -o - | FileCheck --check-prefixes=CHECK,RV64M %s
; RUN: llc -mtriple=riscv64 -mattr=+zmmul %s -o - | FileCheck --check-prefixes=CHECK,RV64ZMMUL %s
; RUN: llc -mtriple=riscv64 -mattr=+m,+zmmul %s -o - | FileCheck --check-prefixes=CHECK,RV64MZMMUL %s
; RUN: llc -mtriple=riscv64 -mattr=+a %s -o - | FileCheck --check-prefixes=CHECK,RV64A %s
; RUN: llc -mtriple=riscv64 -mattr=+a %s -o - | FileCheck --check-prefixes=CHECK,RV64A,A6C %s
; RUN: llc -mtriple=riscv64 -mattr=+a,+seq-cst-trailing-fence %s -o - | FileCheck --check-prefixes=CHECK,RV64A,A6S %s
; RUN: llc -mtriple=riscv64 -mattr=+f %s -o - | FileCheck --check-prefixes=CHECK,RV64F %s
; RUN: llc -mtriple=riscv64 -mattr=+d %s -o - | FileCheck --check-prefixes=CHECK,RV64D %s
; RUN: llc -mtriple=riscv64 -mattr=+c %s -o - | FileCheck --check-prefixes=CHECK,RV64C %s
Expand Down Expand Up @@ -512,3 +513,10 @@ define i32 @addi(i32 %a) {
%1 = add i32 %a, 1
ret i32 %1
}

define i8 @atomic_load_i8_seq_cst(ptr %a) nounwind {
%1 = load atomic i8, ptr %a seq_cst, align 1
ret i8 %1
; A6S: .attribute 14, 2
; A6C: .attribute 14, 1
}
3 changes: 3 additions & 0 deletions llvm/test/MC/RISCV/attribute.s
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Original file line number Diff line number Diff line change
Expand Up @@ -24,3 +24,6 @@

.attribute priv_spec_revision, 0
# CHECK: attribute 12, 0

.attribute atomic_abi, 0
# CHECK: attribute 14, 0
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