[RFC] Extend MemoryEffects to Support Target-Specific Memory Locations #148650
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| @@ -56,6 +56,11 @@ enum class ModRefInfo : uint8_t { | |||
| /// Debug print ModRefInfo. | |||
| LLVM_ABI raw_ostream &operator<<(raw_ostream &OS, ModRefInfo MR); | |||
|
|
|||
| enum class InaccessibleTargetMemLocation { | |||
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Each Target should have an InaccessibleTargetMemLocation, but I am not sure if we should check which Target it is being used in Support, Attributes and so on. I would appreciate some suggestion if this is the right way to do this.
And this is still using Data to model the Memory Locations with ModRef. Is this the only way to add new memory location?
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I wonder if we could have something around the following instead:
enum class IRMemLocation {
ArgMem = 0,
InaccessibleMem = 1,
ErrnoMem = 2,
TargetSpecificMem = 3,
Other = 4,
First = ArgMem,
Last = Other,
};And then extending MemoryEffectsBase to have, like, a Optional<TargetSpecificMemTag> TargetMem; field, where TargetMem is, e.g.,:
struct TargetSpecificMemTag {
Triple::ArchType Arch;
uint8_t Kind;
};This would lead to know easily if the location is target-specific:
bool isTargetSpecific() const { return Loc == Location::TargetSpecificMem; }And I guess it would avoid having some static_cast<IRMemLocation> around. Not sure if the target-specific memory effects are decoupled enough this way though.
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Hi @antoniofrighetto
I will try to follow your suggestion in a next iteration. I am not sure I fully understand the consequences of implementing this way.
For instance: I am not sure I can have only one Kind.
For instance, something like this:
def int_aarch64_get_fpmr_set_za : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_FPMR>, IntrInaccessibleWriteMemOnly<AArch64_ZA>]>;
I imagine that the ModRefInfo for TargetSpecificMem will be 11, that is ModRef.
But how Kind will work in the case above? Do you have an idea? Because we need to set one to just write and another to just read.
I can only think about another TargetMemoryLocation and another vector like Data, but only used when TargetSpecificMem !=NoModRef
I would also have to see how this will work in BasicAliasAnalysis.cpp/getModRefInfo and BitcodeReader.cpp(parseAttributeGroupBlock)
| @@ -656,6 +660,15 @@ std::string Attribute::getAsString(bool InAttrGrp) const { | |||
| break; | |||
| case IRMemLocation::Other: | |||
| llvm_unreachable("This is represented as the default access kind"); | |||
| default: { | |||
| InaccessibleTargetMemLocation TargetLoc = | |||
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How can we make this to not be target specific? Any suggestion?
nikic
reviewed
Jul 14, 2025
|
Making things target-specific at this level is not worthwhile. Similar to how intrinsics are always defined, regardless of whether the corresponding target was built, these can also just always be available, but will only be used for specific targets. |
…ocations This patch introduces preliminary support for additional memory locations, such as FPMR and ZA, needed to model AArch64 architectural registers as memory dependencies. Currently, these locations are not yet target-specific. The goal is to enable the compiler to express read/write effects on these resources. What This Patch Does: Adds two new memory locations: FPMR and ZA, intended to represent AArch64-specific inaccessible memory types. Current Limitations: These new locations are not yet target-specific in the type-safe sense, they are globally visible and hardcoded. There is no mechanism yet to associate a memory location with its corresponding target (e.g., AArch64 vs RISCV). No changes are made yet to bitcode serialization, parser support, or alias analysis behavior. This patch is not functionally complete — it is a structural prototype to solicit feedback on the direction and I would like some suggestion on how to proceed.
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This patch is removing the keyworkd and token inaccessibleWrite and inaccessibleRead. It is using Read and Write to set the Target Memory Location. Adding "aarch64" in front of the target specific memory locations
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Hi @nikic , Thank you for your comments, I do have some extra notes. My concern is that with Data being 32 bits and reserving 2 bits for each location, there are 16 memory locations available. There are 3 already being reserved to ArgMem, InaccessibleMem and Other. Now AArch64 is using 2(AArch64_FPRM and AArch64_ZA, I will probably expand to use for ZT0), if each target adds its own location it could be out of space with Data. Any suggestion how to implement the Target Memory Location? The way it is implemented the Target Memory Locations for now is correct ? Should I change? Another question, should we treat these extra locations as Inaccessible memory as well? |
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@llvm/pr-subscribers-tablegen @llvm/pr-subscribers-llvm-support Author: None (CarolineConcatto) Changes…ocations This patch introduces preliminary support for additional memory locations, such as FPMR and ZA, needed to model AArch64 architectural registers as memory dependencies. It was a solution suggested in : https://discourse.llvm.org/t/rfc-improving-fpmr-handling-for-fp8-intrinsics-in-llvm/86868/6 Currently, these locations are not yet target-specific. The goal is to enable the compiler to express read/write effects on these resources. What This Patch Does: Current Limitations: This patch is not functionally complete — it is a structural prototype to solicit feedback on the direction and I would like some suggestion on how to proceed. Full diff: https://github.com/llvm/llvm-project/pull/148650.diff 15 Files Affected:
diff --git a/llvm/include/llvm/AsmParser/LLToken.h b/llvm/include/llvm/AsmParser/LLToken.h
index c7e4bdf3ff811..c08eb99c1f5b2 100644
--- a/llvm/include/llvm/AsmParser/LLToken.h
+++ b/llvm/include/llvm/AsmParser/LLToken.h
@@ -202,6 +202,8 @@ enum Kind {
kw_readwrite,
kw_argmem,
kw_inaccessiblemem,
+ kw_aarch64_fpmr,
+ kw_aarch64_za,
kw_errnomem,
// Legacy attributes:
diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index bd6f94ac1286c..ad1b0b462be37 100644
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -49,6 +49,17 @@ def IntrArgMemOnly : IntrinsicProperty;
// accessible by the module being compiled. This is a weaker form of IntrNoMem.
def IntrInaccessibleMemOnly : IntrinsicProperty;
+
+
+class IntrinsicMemoryLocation;
+// This should be added in the Target, but once in IntrinsicsAArch64.td
+// It complains error: "Variable not defined: 'AArch64_FPMR'"
+def AArch64_FPMR : IntrinsicMemoryLocation;
+def AArch64_ZA: IntrinsicMemoryLocation;
+// IntrInaccessible{Read|Write}MemOnly needs to set Location
+class IntrInaccessibleReadMemOnly<IntrinsicMemoryLocation idx> : IntrinsicProperty{IntrinsicMemoryLocation Loc=idx;}
+class IntrInaccessibleWriteMemOnly<IntrinsicMemoryLocation idx> : IntrinsicProperty{IntrinsicMemoryLocation Loc=idx;}
+
// IntrInaccessibleMemOrArgMemOnly -- This intrinsic only accesses memory that
// its pointer-typed arguments point to or memory that is not accessible
// by the module being compiled. This is a weaker form of IntrArgMemOnly.
diff --git a/llvm/include/llvm/Support/ModRef.h b/llvm/include/llvm/Support/ModRef.h
index 71f3b5bcb9c2b..0de2b02e4e05a 100644
--- a/llvm/include/llvm/Support/ModRef.h
+++ b/llvm/include/llvm/Support/ModRef.h
@@ -56,6 +56,11 @@ enum class ModRefInfo : uint8_t {
/// Debug print ModRefInfo.
LLVM_ABI raw_ostream &operator<<(raw_ostream &OS, ModRefInfo MR);
+enum class InaccessibleTargetMemLocation {
+ AARCH64_FPMR = 3,
+ AARCH64_ZA = 4,
+};
+
/// The locations at which a function might access memory.
enum class IRMemLocation {
/// Access to memory via argument pointers.
@@ -65,7 +70,7 @@ enum class IRMemLocation {
/// Errno memory.
ErrnoMem = 2,
/// Any other memory.
- Other = 3,
+ Other = 5,
/// Helpers to iterate all locations in the MemoryEffectsBase class.
First = ArgMem,
@@ -152,6 +157,40 @@ template <typename LocationEnum> class MemoryEffectsBase {
return MemoryEffectsBase(Location::Other, MR);
}
+ /// Create MemoryEffectsBase that can only read inaccessible memory.
+ static MemoryEffectsBase
+ inaccessibleReadMemOnly(Location Loc = Location::InaccessibleMem) {
+ return MemoryEffectsBase(Loc, ModRefInfo::Ref);
+ }
+
+ /// Create MemoryEffectsBase that can only write inaccessible memory.
+ static MemoryEffectsBase
+ inaccessibleWriteMemOnly(Location Loc = Location::InaccessibleMem) {
+ return MemoryEffectsBase(Loc, ModRefInfo::Mod);
+ }
+
+ /// Checks if only target-specific memory locations are set.
+ /// Ignores standard locations like ArgMem or InaccessibleMem.
+ /// Needed because `Data` may be non-zero by default unless explicitly
+ /// cleared.
+ bool onlyAccessTargetMemoryLocation() {
+ MemoryEffectsBase ME = *this;
+ for (unsigned I = static_cast<int>(LocationEnum::ErrnoMem);
+ I < static_cast<int>(LocationEnum::Last); I++)
+ ME = ME.getWithoutLoc(static_cast<IRMemLocation>(I));
+ return ME.doesNotAccessMemory();
+ }
+
+ /// Create MemoryEffectsBase that can only access Target Memory Locations
+ static MemoryEffectsBase
+ setTargetMemLocationModRef(ModRefInfo MR = ModRefInfo::NoModRef) {
+ MemoryEffectsBase FRMB = none();
+ for (unsigned I = static_cast<int>(LocationEnum::ErrnoMem);
+ I < static_cast<int>(LocationEnum::Last); I++)
+ FRMB.setModRef(static_cast<Location>(I), MR);
+ return FRMB;
+ }
+
/// Create MemoryEffectsBase that can only access inaccessible or argument
/// memory.
static MemoryEffectsBase
@@ -178,6 +217,11 @@ template <typename LocationEnum> class MemoryEffectsBase {
return MemoryEffectsBase(Data);
}
+ bool isTargetMemLoc(IRMemLocation Loc) {
+ return static_cast<unsigned>(Loc) >
+ static_cast<unsigned>(Location::ErrnoMem);
+ }
+
/// Convert MemoryEffectsBase into an encoded integer value (used by memory
/// attribute).
uint32_t toIntValue() const {
diff --git a/llvm/include/llvm/TableGen/Record.h b/llvm/include/llvm/TableGen/Record.h
index a2b86eb8e7cad..5aeb331c49c9b 100644
--- a/llvm/include/llvm/TableGen/Record.h
+++ b/llvm/include/llvm/TableGen/Record.h
@@ -25,6 +25,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/ModRef.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/TrailingObjects.h"
@@ -1961,6 +1962,8 @@ class Record {
/// value is not the right type.
int64_t getValueAsInt(StringRef FieldName) const;
+ llvm::IRMemLocation getLocationTypeAsInt(StringRef FieldName) const;
+
/// This method looks up the specified field and returns its value as an Dag,
/// throwing an exception if the field does not exist or if the value is not
/// the right type.
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index ce813e1d7b1c4..c086f9f9585a2 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -701,6 +701,8 @@ lltok::Kind LLLexer::LexIdentifier() {
KEYWORD(write);
KEYWORD(readwrite);
KEYWORD(argmem);
+ KEYWORD(aarch64_fpmr);
+ KEYWORD(aarch64_za);
KEYWORD(inaccessiblemem);
KEYWORD(errnomem);
KEYWORD(argmemonly);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index b7f6950f679ef..abde2993bb048 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1666,6 +1666,25 @@ static bool upgradeMemoryAttr(MemoryEffects &ME, lltok::Kind Kind) {
}
}
+static std::optional<MemoryEffects::Location> keywordToLoc(lltok::Kind Tok) {
+ switch (Tok) {
+ case lltok::kw_argmem:
+ return IRMemLocation::ArgMem;
+ case lltok::kw_inaccessiblemem:
+ return IRMemLocation::InaccessibleMem;
+ case lltok::kw_errnomem:
+ return IRMemLocation::ErrnoMem;
+ case lltok::kw_aarch64_fpmr:
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_FPMR);
+ case lltok::kw_aarch64_za:
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_ZA);
+ default:
+ return std::nullopt;
+ }
+}
+
/// parseFnAttributeValuePairs
/// ::= <attr> | <attr> '=' <value>
bool LLParser::parseFnAttributeValuePairs(AttrBuilder &B,
@@ -2510,19 +2529,6 @@ bool LLParser::parseAllocKind(AllocFnKind &Kind) {
return false;
}
-static std::optional<MemoryEffects::Location> keywordToLoc(lltok::Kind Tok) {
- switch (Tok) {
- case lltok::kw_argmem:
- return IRMemLocation::ArgMem;
- case lltok::kw_inaccessiblemem:
- return IRMemLocation::InaccessibleMem;
- case lltok::kw_errnomem:
- return IRMemLocation::ErrnoMem;
- default:
- return std::nullopt;
- }
-}
-
static std::optional<ModRefInfo> keywordToModRef(lltok::Kind Tok) {
switch (Tok) {
case lltok::kw_none:
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index d1fbcb9e893a7..37e9d7c5c74db 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -640,6 +640,10 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
if (MR == OtherMR)
continue;
+ // Dont want to print Target Location if NoModRef
+ if (ME.isTargetMemLoc(Loc) && (MR == ModRefInfo::NoModRef))
+ continue;
+
if (!First)
OS << ", ";
First = false;
@@ -656,6 +660,15 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
break;
case IRMemLocation::Other:
llvm_unreachable("This is represented as the default access kind");
+ default: {
+ InaccessibleTargetMemLocation TargetLoc =
+ static_cast<InaccessibleTargetMemLocation>(Loc);
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_FPMR)
+ OS << "aarch64_fpmr: ";
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_ZA)
+ OS << "aarch64_za: ";
+ break;
+ }
}
OS << getModRefStr(MR);
}
diff --git a/llvm/lib/Support/ModRef.cpp b/llvm/lib/Support/ModRef.cpp
index 2bb9bc945bd2e..dc0dafdbe7e49 100644
--- a/llvm/lib/Support/ModRef.cpp
+++ b/llvm/lib/Support/ModRef.cpp
@@ -49,6 +49,15 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, MemoryEffects ME) {
case IRMemLocation::Other:
OS << "Other: ";
break;
+ default: {
+ InaccessibleTargetMemLocation TargetLoc =
+ static_cast<InaccessibleTargetMemLocation>(Loc);
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_FPMR)
+ OS << "AARCH64_FPMR: ";
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_ZA)
+ OS << "AARCH64_ZA: ";
+ break;
+ }
}
OS << ME.getModRef(Loc);
});
diff --git a/llvm/lib/TableGen/Record.cpp b/llvm/lib/TableGen/Record.cpp
index 1f3e5dc68f1d6..d114358266737 100644
--- a/llvm/lib/TableGen/Record.cpp
+++ b/llvm/lib/TableGen/Record.cpp
@@ -3102,6 +3102,21 @@ Record::getValueAsListOfDefs(StringRef FieldName) const {
return Defs;
}
+llvm::IRMemLocation Record::getLocationTypeAsInt(StringRef FieldName) const {
+ const Record *LocRec = getValueAsDef(FieldName);
+ StringRef Name = LocRec->getName();
+ if (Name == "AArch64_FPMR")
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_FPMR);
+ else if (Name == "AArch64_ZA")
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_ZA);
+ else if (Name == "InaccessibleMem")
+ return llvm::IRMemLocation::InaccessibleMem;
+ else
+ PrintFatalError(getLoc(), "unknown IRMemLocation: " + Name);
+}
+
int64_t Record::getValueAsInt(StringRef FieldName) const {
const RecordVal *R = getValue(FieldName);
if (!R || !R->getValue())
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index f43202eea6306..49b822b3ef38e 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -143,6 +143,9 @@ static void addLocAccess(MemoryEffects &ME, const MemoryLocation &Loc,
ME |= MemoryEffects::argMemOnly(MR);
ME |= MemoryEffects(IRMemLocation::ErrnoMem, MR);
ME |= MemoryEffects(IRMemLocation::Other, MR);
+ // Should also set the other Target Memory Locations as MR.
+ // To compares with MemoryEffects::unknown() in addMemoryAttrs
+ ME |= MemoryEffects::setTargetMemLocationModRef(MR);
}
static void addArgLocs(MemoryEffects &ME, const CallBase *Call,
diff --git a/llvm/test/Assembler/memory-attribute.ll b/llvm/test/Assembler/memory-attribute.ll
index effd4ce7c4548..42f9b9f87e8b0 100644
--- a/llvm/test/Assembler/memory-attribute.ll
+++ b/llvm/test/Assembler/memory-attribute.ll
@@ -78,3 +78,28 @@ declare void @fn_argmem_read_inaccessiblemem_write()
; CHECK: @fn_argmem_read_inaccessiblemem_write_reordered()
declare void @fn_argmem_read_inaccessiblemem_write_reordered()
memory(inaccessiblemem: write, argmem: read)
+
+; CHECK: Function Attrs: memory(aarch64_za: write)
+; CHECK: @fn_inaccessiblemem_write_aarch64_za()
+declare void @fn_inaccessiblemem_write_aarch64_za()
+ memory(aarch64_za: write)
+
+; CHECK: Function Attrs: memory(aarch64_za: read)
+; CHECK: @fn_inaccessiblemem_read_aarch64_za()
+declare void @fn_inaccessiblemem_read_aarch64_za()
+ memory(aarch64_za: read)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: write)
+; CHECK: @fn_inaccessiblemem_write_aarch64_fpmr()
+declare void @fn_inaccessiblemem_write_aarch64_fpmr()
+ memory(aarch64_fpmr: write)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: read)
+; CHECK: @fn_inaccessiblemem_read_aarch64_fpmr()
+declare void @fn_inaccessiblemem_read_aarch64_fpmr()
+ memory(aarch64_fpmr: read)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: read, aarch64_za: write)
+; CHECK: @fn_inaccessiblemem_read_aarch64_fpmr_write_aarch64_za()
+declare void @fn_inaccessiblemem_read_aarch64_fpmr_write_aarch64_za()
+ memory(aarch64_fpmr: read, aarch64_za: write)
diff --git a/llvm/test/Bitcode/attributes.ll b/llvm/test/Bitcode/attributes.ll
index 8c1a76365e1b4..8e72e7ade54c1 100644
--- a/llvm/test/Bitcode/attributes.ll
+++ b/llvm/test/Bitcode/attributes.ll
@@ -572,7 +572,6 @@ define void @dead_on_return(ptr dead_on_return %p) {
ret void
}
-; CHECK: attributes #0 = { noreturn }
; CHECK: attributes #1 = { nounwind }
; CHECK: attributes #2 = { memory(none) }
; CHECK: attributes #3 = { memory(read) }
diff --git a/llvm/test/TableGen/intrinsic-attrs-fp8.td b/llvm/test/TableGen/intrinsic-attrs-fp8.td
new file mode 100644
index 0000000000000..5aaba44edcc45
--- /dev/null
+++ b/llvm/test/TableGen/intrinsic-attrs-fp8.td
@@ -0,0 +1,54 @@
+// RUN: llvm-tblgen -gen-intrinsic-impl -I %p/../../include -DTEST_INTRINSICS_SUPPRESS_DEFS %s | FileCheck %s
+
+include "llvm/IR/Intrinsics.td"
+
+def int_aarch64_set_fpmr_2 : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleWriteMemOnly<AArch64_FPMR>]>;
+
+def int_aarch64_get_za_2 : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_ZA>]>;
+
+def int_aarch64_get_fpmr_set_za : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_FPMR>, IntrInaccessibleWriteMemOnly<AArch64_ZA>]>;
+
+// CHECK: static constexpr unsigned IntrinsicNameOffsetTable[] = {
+// CHECK-NEXT: 1, // not_intrinsic
+// CHECK-NEXT: 15, // llvm.aarch64.get.fpmr.set.za
+// CHECK-NEXT: 44, // llvm.aarch64.get.za.2
+// CHECK-NEXT: 66, // llvm.aarch64.set.fpmr.2
+
+// CHECK: static AttributeSet getIntrinsicFnAttributeSet(LLVMContext &C, unsigned ID) {
+// CHECK-NEXT: switch (ID) {
+// CHECK-NEXT: default: llvm_unreachable("Invalid attribute set number");
+// CHECK-NEXT: case 0:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: Ref, AARCH64_ZA: Mod, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(576)),
+// CHECK-NEXT: });
+// CHECK-NEXT: case 1:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: NoModRef, AARCH64_ZA: Ref, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(256)),
+// CHECK-NEXT: });
+// CHECK-NEXT: case 2:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: Mod, AARCH64_ZA: NoModRef, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(128)),
+
+// CHECK: static constexpr uint16_t IntrinsicsToAttributesMap[] = {
+// CHECK-NEXT: 0 << 8 | 0, // llvm.aarch64.get.fpmr.set.za
+// CHECK-NEXT: 1 << 8 | 0, // llvm.aarch64.get.za.2
+// CHECK-NEXT: 2 << 8 | 0, // llvm.aarch64.set.fpmr.2
+// CHECK-NEXT:};
diff --git a/llvm/unittests/Support/ModRefTest.cpp b/llvm/unittests/Support/ModRefTest.cpp
index 9c13908da44bb..7aa473ad20336 100644
--- a/llvm/unittests/Support/ModRefTest.cpp
+++ b/llvm/unittests/Support/ModRefTest.cpp
@@ -21,7 +21,8 @@ TEST(ModRefTest, PrintMemoryEffects) {
raw_string_ostream OS(S);
OS << MemoryEffects::none();
EXPECT_EQ(S, "ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: "
- "NoModRef, Other: NoModRef");
+ "NoModRef, AARCH64_FPMR: NoModRef, AARCH64_ZA: NoModRef, Other: "
+ "NoModRef");
}
} // namespace
diff --git a/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp b/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
index bc42efa3b2e9c..eb2d4de7e9320 100644
--- a/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
+++ b/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
@@ -374,7 +374,19 @@ void CodeGenIntrinsic::setProperty(const Record *R) {
ME &= MemoryEffects::argMemOnly();
else if (R->getName() == "IntrInaccessibleMemOnly")
ME &= MemoryEffects::inaccessibleMemOnly();
- else if (R->getName() == "IntrInaccessibleMemOrArgMemOnly")
+ else if (R->isSubClassOf("IntrInaccessibleReadMemOnly")) {
+ llvm::IRMemLocation Loc = R->getLocationTypeAsInt("Loc");
+ if (ME.onlyAccessTargetMemoryLocation())
+ ME = ME.getWithModRef(Loc, ModRefInfo::Ref);
+ else
+ ME &= MemoryEffects::inaccessibleReadMemOnly(Loc);
+ } else if (R->isSubClassOf("IntrInaccessibleWriteMemOnly")) {
+ llvm::IRMemLocation Loc = R->getLocationTypeAsInt("Loc");
+ if (ME.onlyAccessTargetMemoryLocation())
+ ME = ME.getWithModRef(Loc, ModRefInfo::Mod);
+ else
+ ME &= MemoryEffects::inaccessibleWriteMemOnly(Loc);
+ } else if (R->getName() == "IntrInaccessibleMemOrArgMemOnly")
ME &= MemoryEffects::inaccessibleOrArgMemOnly();
else if (R->getName() == "Commutative")
isCommutative = true;
|
|
@llvm/pr-subscribers-llvm-transforms Author: None (CarolineConcatto) Changes…ocations This patch introduces preliminary support for additional memory locations, such as FPMR and ZA, needed to model AArch64 architectural registers as memory dependencies. It was a solution suggested in : https://discourse.llvm.org/t/rfc-improving-fpmr-handling-for-fp8-intrinsics-in-llvm/86868/6 Currently, these locations are not yet target-specific. The goal is to enable the compiler to express read/write effects on these resources. What This Patch Does: Current Limitations: This patch is not functionally complete — it is a structural prototype to solicit feedback on the direction and I would like some suggestion on how to proceed. Full diff: https://github.com/llvm/llvm-project/pull/148650.diff 15 Files Affected:
diff --git a/llvm/include/llvm/AsmParser/LLToken.h b/llvm/include/llvm/AsmParser/LLToken.h
index c7e4bdf3ff811..c08eb99c1f5b2 100644
--- a/llvm/include/llvm/AsmParser/LLToken.h
+++ b/llvm/include/llvm/AsmParser/LLToken.h
@@ -202,6 +202,8 @@ enum Kind {
kw_readwrite,
kw_argmem,
kw_inaccessiblemem,
+ kw_aarch64_fpmr,
+ kw_aarch64_za,
kw_errnomem,
// Legacy attributes:
diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index bd6f94ac1286c..ad1b0b462be37 100644
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -49,6 +49,17 @@ def IntrArgMemOnly : IntrinsicProperty;
// accessible by the module being compiled. This is a weaker form of IntrNoMem.
def IntrInaccessibleMemOnly : IntrinsicProperty;
+
+
+class IntrinsicMemoryLocation;
+// This should be added in the Target, but once in IntrinsicsAArch64.td
+// It complains error: "Variable not defined: 'AArch64_FPMR'"
+def AArch64_FPMR : IntrinsicMemoryLocation;
+def AArch64_ZA: IntrinsicMemoryLocation;
+// IntrInaccessible{Read|Write}MemOnly needs to set Location
+class IntrInaccessibleReadMemOnly<IntrinsicMemoryLocation idx> : IntrinsicProperty{IntrinsicMemoryLocation Loc=idx;}
+class IntrInaccessibleWriteMemOnly<IntrinsicMemoryLocation idx> : IntrinsicProperty{IntrinsicMemoryLocation Loc=idx;}
+
// IntrInaccessibleMemOrArgMemOnly -- This intrinsic only accesses memory that
// its pointer-typed arguments point to or memory that is not accessible
// by the module being compiled. This is a weaker form of IntrArgMemOnly.
diff --git a/llvm/include/llvm/Support/ModRef.h b/llvm/include/llvm/Support/ModRef.h
index 71f3b5bcb9c2b..0de2b02e4e05a 100644
--- a/llvm/include/llvm/Support/ModRef.h
+++ b/llvm/include/llvm/Support/ModRef.h
@@ -56,6 +56,11 @@ enum class ModRefInfo : uint8_t {
/// Debug print ModRefInfo.
LLVM_ABI raw_ostream &operator<<(raw_ostream &OS, ModRefInfo MR);
+enum class InaccessibleTargetMemLocation {
+ AARCH64_FPMR = 3,
+ AARCH64_ZA = 4,
+};
+
/// The locations at which a function might access memory.
enum class IRMemLocation {
/// Access to memory via argument pointers.
@@ -65,7 +70,7 @@ enum class IRMemLocation {
/// Errno memory.
ErrnoMem = 2,
/// Any other memory.
- Other = 3,
+ Other = 5,
/// Helpers to iterate all locations in the MemoryEffectsBase class.
First = ArgMem,
@@ -152,6 +157,40 @@ template <typename LocationEnum> class MemoryEffectsBase {
return MemoryEffectsBase(Location::Other, MR);
}
+ /// Create MemoryEffectsBase that can only read inaccessible memory.
+ static MemoryEffectsBase
+ inaccessibleReadMemOnly(Location Loc = Location::InaccessibleMem) {
+ return MemoryEffectsBase(Loc, ModRefInfo::Ref);
+ }
+
+ /// Create MemoryEffectsBase that can only write inaccessible memory.
+ static MemoryEffectsBase
+ inaccessibleWriteMemOnly(Location Loc = Location::InaccessibleMem) {
+ return MemoryEffectsBase(Loc, ModRefInfo::Mod);
+ }
+
+ /// Checks if only target-specific memory locations are set.
+ /// Ignores standard locations like ArgMem or InaccessibleMem.
+ /// Needed because `Data` may be non-zero by default unless explicitly
+ /// cleared.
+ bool onlyAccessTargetMemoryLocation() {
+ MemoryEffectsBase ME = *this;
+ for (unsigned I = static_cast<int>(LocationEnum::ErrnoMem);
+ I < static_cast<int>(LocationEnum::Last); I++)
+ ME = ME.getWithoutLoc(static_cast<IRMemLocation>(I));
+ return ME.doesNotAccessMemory();
+ }
+
+ /// Create MemoryEffectsBase that can only access Target Memory Locations
+ static MemoryEffectsBase
+ setTargetMemLocationModRef(ModRefInfo MR = ModRefInfo::NoModRef) {
+ MemoryEffectsBase FRMB = none();
+ for (unsigned I = static_cast<int>(LocationEnum::ErrnoMem);
+ I < static_cast<int>(LocationEnum::Last); I++)
+ FRMB.setModRef(static_cast<Location>(I), MR);
+ return FRMB;
+ }
+
/// Create MemoryEffectsBase that can only access inaccessible or argument
/// memory.
static MemoryEffectsBase
@@ -178,6 +217,11 @@ template <typename LocationEnum> class MemoryEffectsBase {
return MemoryEffectsBase(Data);
}
+ bool isTargetMemLoc(IRMemLocation Loc) {
+ return static_cast<unsigned>(Loc) >
+ static_cast<unsigned>(Location::ErrnoMem);
+ }
+
/// Convert MemoryEffectsBase into an encoded integer value (used by memory
/// attribute).
uint32_t toIntValue() const {
diff --git a/llvm/include/llvm/TableGen/Record.h b/llvm/include/llvm/TableGen/Record.h
index a2b86eb8e7cad..5aeb331c49c9b 100644
--- a/llvm/include/llvm/TableGen/Record.h
+++ b/llvm/include/llvm/TableGen/Record.h
@@ -25,6 +25,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/ModRef.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/TrailingObjects.h"
@@ -1961,6 +1962,8 @@ class Record {
/// value is not the right type.
int64_t getValueAsInt(StringRef FieldName) const;
+ llvm::IRMemLocation getLocationTypeAsInt(StringRef FieldName) const;
+
/// This method looks up the specified field and returns its value as an Dag,
/// throwing an exception if the field does not exist or if the value is not
/// the right type.
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index ce813e1d7b1c4..c086f9f9585a2 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -701,6 +701,8 @@ lltok::Kind LLLexer::LexIdentifier() {
KEYWORD(write);
KEYWORD(readwrite);
KEYWORD(argmem);
+ KEYWORD(aarch64_fpmr);
+ KEYWORD(aarch64_za);
KEYWORD(inaccessiblemem);
KEYWORD(errnomem);
KEYWORD(argmemonly);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index b7f6950f679ef..abde2993bb048 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1666,6 +1666,25 @@ static bool upgradeMemoryAttr(MemoryEffects &ME, lltok::Kind Kind) {
}
}
+static std::optional<MemoryEffects::Location> keywordToLoc(lltok::Kind Tok) {
+ switch (Tok) {
+ case lltok::kw_argmem:
+ return IRMemLocation::ArgMem;
+ case lltok::kw_inaccessiblemem:
+ return IRMemLocation::InaccessibleMem;
+ case lltok::kw_errnomem:
+ return IRMemLocation::ErrnoMem;
+ case lltok::kw_aarch64_fpmr:
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_FPMR);
+ case lltok::kw_aarch64_za:
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_ZA);
+ default:
+ return std::nullopt;
+ }
+}
+
/// parseFnAttributeValuePairs
/// ::= <attr> | <attr> '=' <value>
bool LLParser::parseFnAttributeValuePairs(AttrBuilder &B,
@@ -2510,19 +2529,6 @@ bool LLParser::parseAllocKind(AllocFnKind &Kind) {
return false;
}
-static std::optional<MemoryEffects::Location> keywordToLoc(lltok::Kind Tok) {
- switch (Tok) {
- case lltok::kw_argmem:
- return IRMemLocation::ArgMem;
- case lltok::kw_inaccessiblemem:
- return IRMemLocation::InaccessibleMem;
- case lltok::kw_errnomem:
- return IRMemLocation::ErrnoMem;
- default:
- return std::nullopt;
- }
-}
-
static std::optional<ModRefInfo> keywordToModRef(lltok::Kind Tok) {
switch (Tok) {
case lltok::kw_none:
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index d1fbcb9e893a7..37e9d7c5c74db 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -640,6 +640,10 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
if (MR == OtherMR)
continue;
+ // Dont want to print Target Location if NoModRef
+ if (ME.isTargetMemLoc(Loc) && (MR == ModRefInfo::NoModRef))
+ continue;
+
if (!First)
OS << ", ";
First = false;
@@ -656,6 +660,15 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
break;
case IRMemLocation::Other:
llvm_unreachable("This is represented as the default access kind");
+ default: {
+ InaccessibleTargetMemLocation TargetLoc =
+ static_cast<InaccessibleTargetMemLocation>(Loc);
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_FPMR)
+ OS << "aarch64_fpmr: ";
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_ZA)
+ OS << "aarch64_za: ";
+ break;
+ }
}
OS << getModRefStr(MR);
}
diff --git a/llvm/lib/Support/ModRef.cpp b/llvm/lib/Support/ModRef.cpp
index 2bb9bc945bd2e..dc0dafdbe7e49 100644
--- a/llvm/lib/Support/ModRef.cpp
+++ b/llvm/lib/Support/ModRef.cpp
@@ -49,6 +49,15 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, MemoryEffects ME) {
case IRMemLocation::Other:
OS << "Other: ";
break;
+ default: {
+ InaccessibleTargetMemLocation TargetLoc =
+ static_cast<InaccessibleTargetMemLocation>(Loc);
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_FPMR)
+ OS << "AARCH64_FPMR: ";
+ if (TargetLoc == InaccessibleTargetMemLocation::AARCH64_ZA)
+ OS << "AARCH64_ZA: ";
+ break;
+ }
}
OS << ME.getModRef(Loc);
});
diff --git a/llvm/lib/TableGen/Record.cpp b/llvm/lib/TableGen/Record.cpp
index 1f3e5dc68f1d6..d114358266737 100644
--- a/llvm/lib/TableGen/Record.cpp
+++ b/llvm/lib/TableGen/Record.cpp
@@ -3102,6 +3102,21 @@ Record::getValueAsListOfDefs(StringRef FieldName) const {
return Defs;
}
+llvm::IRMemLocation Record::getLocationTypeAsInt(StringRef FieldName) const {
+ const Record *LocRec = getValueAsDef(FieldName);
+ StringRef Name = LocRec->getName();
+ if (Name == "AArch64_FPMR")
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_FPMR);
+ else if (Name == "AArch64_ZA")
+ return static_cast<IRMemLocation>(
+ llvm::InaccessibleTargetMemLocation::AARCH64_ZA);
+ else if (Name == "InaccessibleMem")
+ return llvm::IRMemLocation::InaccessibleMem;
+ else
+ PrintFatalError(getLoc(), "unknown IRMemLocation: " + Name);
+}
+
int64_t Record::getValueAsInt(StringRef FieldName) const {
const RecordVal *R = getValue(FieldName);
if (!R || !R->getValue())
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index f43202eea6306..49b822b3ef38e 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -143,6 +143,9 @@ static void addLocAccess(MemoryEffects &ME, const MemoryLocation &Loc,
ME |= MemoryEffects::argMemOnly(MR);
ME |= MemoryEffects(IRMemLocation::ErrnoMem, MR);
ME |= MemoryEffects(IRMemLocation::Other, MR);
+ // Should also set the other Target Memory Locations as MR.
+ // To compares with MemoryEffects::unknown() in addMemoryAttrs
+ ME |= MemoryEffects::setTargetMemLocationModRef(MR);
}
static void addArgLocs(MemoryEffects &ME, const CallBase *Call,
diff --git a/llvm/test/Assembler/memory-attribute.ll b/llvm/test/Assembler/memory-attribute.ll
index effd4ce7c4548..42f9b9f87e8b0 100644
--- a/llvm/test/Assembler/memory-attribute.ll
+++ b/llvm/test/Assembler/memory-attribute.ll
@@ -78,3 +78,28 @@ declare void @fn_argmem_read_inaccessiblemem_write()
; CHECK: @fn_argmem_read_inaccessiblemem_write_reordered()
declare void @fn_argmem_read_inaccessiblemem_write_reordered()
memory(inaccessiblemem: write, argmem: read)
+
+; CHECK: Function Attrs: memory(aarch64_za: write)
+; CHECK: @fn_inaccessiblemem_write_aarch64_za()
+declare void @fn_inaccessiblemem_write_aarch64_za()
+ memory(aarch64_za: write)
+
+; CHECK: Function Attrs: memory(aarch64_za: read)
+; CHECK: @fn_inaccessiblemem_read_aarch64_za()
+declare void @fn_inaccessiblemem_read_aarch64_za()
+ memory(aarch64_za: read)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: write)
+; CHECK: @fn_inaccessiblemem_write_aarch64_fpmr()
+declare void @fn_inaccessiblemem_write_aarch64_fpmr()
+ memory(aarch64_fpmr: write)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: read)
+; CHECK: @fn_inaccessiblemem_read_aarch64_fpmr()
+declare void @fn_inaccessiblemem_read_aarch64_fpmr()
+ memory(aarch64_fpmr: read)
+
+; CHECK: Function Attrs: memory(aarch64_fpmr: read, aarch64_za: write)
+; CHECK: @fn_inaccessiblemem_read_aarch64_fpmr_write_aarch64_za()
+declare void @fn_inaccessiblemem_read_aarch64_fpmr_write_aarch64_za()
+ memory(aarch64_fpmr: read, aarch64_za: write)
diff --git a/llvm/test/Bitcode/attributes.ll b/llvm/test/Bitcode/attributes.ll
index 8c1a76365e1b4..8e72e7ade54c1 100644
--- a/llvm/test/Bitcode/attributes.ll
+++ b/llvm/test/Bitcode/attributes.ll
@@ -572,7 +572,6 @@ define void @dead_on_return(ptr dead_on_return %p) {
ret void
}
-; CHECK: attributes #0 = { noreturn }
; CHECK: attributes #1 = { nounwind }
; CHECK: attributes #2 = { memory(none) }
; CHECK: attributes #3 = { memory(read) }
diff --git a/llvm/test/TableGen/intrinsic-attrs-fp8.td b/llvm/test/TableGen/intrinsic-attrs-fp8.td
new file mode 100644
index 0000000000000..5aaba44edcc45
--- /dev/null
+++ b/llvm/test/TableGen/intrinsic-attrs-fp8.td
@@ -0,0 +1,54 @@
+// RUN: llvm-tblgen -gen-intrinsic-impl -I %p/../../include -DTEST_INTRINSICS_SUPPRESS_DEFS %s | FileCheck %s
+
+include "llvm/IR/Intrinsics.td"
+
+def int_aarch64_set_fpmr_2 : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleWriteMemOnly<AArch64_FPMR>]>;
+
+def int_aarch64_get_za_2 : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_ZA>]>;
+
+def int_aarch64_get_fpmr_set_za : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_FPMR>, IntrInaccessibleWriteMemOnly<AArch64_ZA>]>;
+
+// CHECK: static constexpr unsigned IntrinsicNameOffsetTable[] = {
+// CHECK-NEXT: 1, // not_intrinsic
+// CHECK-NEXT: 15, // llvm.aarch64.get.fpmr.set.za
+// CHECK-NEXT: 44, // llvm.aarch64.get.za.2
+// CHECK-NEXT: 66, // llvm.aarch64.set.fpmr.2
+
+// CHECK: static AttributeSet getIntrinsicFnAttributeSet(LLVMContext &C, unsigned ID) {
+// CHECK-NEXT: switch (ID) {
+// CHECK-NEXT: default: llvm_unreachable("Invalid attribute set number");
+// CHECK-NEXT: case 0:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: Ref, AARCH64_ZA: Mod, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(576)),
+// CHECK-NEXT: });
+// CHECK-NEXT: case 1:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: NoModRef, AARCH64_ZA: Ref, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(256)),
+// CHECK-NEXT: });
+// CHECK-NEXT: case 2:
+// CHECK-NEXT: return AttributeSet::get(C, {
+// CHECK-NEXT: Attribute::get(C, Attribute::NoUnwind),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoCallback),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoSync),
+// CHECK-NEXT: Attribute::get(C, Attribute::NoFree),
+// CHECK-NEXT: Attribute::get(C, Attribute::WillReturn),
+// CHECK-NEXT: // ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: NoModRef, AARCH64_FPMR: Mod, AARCH64_ZA: NoModRef, Other: NoModRef
+// CHECK-NEXT: Attribute::getWithMemoryEffects(C, MemoryEffects::createFromIntValue(128)),
+
+// CHECK: static constexpr uint16_t IntrinsicsToAttributesMap[] = {
+// CHECK-NEXT: 0 << 8 | 0, // llvm.aarch64.get.fpmr.set.za
+// CHECK-NEXT: 1 << 8 | 0, // llvm.aarch64.get.za.2
+// CHECK-NEXT: 2 << 8 | 0, // llvm.aarch64.set.fpmr.2
+// CHECK-NEXT:};
diff --git a/llvm/unittests/Support/ModRefTest.cpp b/llvm/unittests/Support/ModRefTest.cpp
index 9c13908da44bb..7aa473ad20336 100644
--- a/llvm/unittests/Support/ModRefTest.cpp
+++ b/llvm/unittests/Support/ModRefTest.cpp
@@ -21,7 +21,8 @@ TEST(ModRefTest, PrintMemoryEffects) {
raw_string_ostream OS(S);
OS << MemoryEffects::none();
EXPECT_EQ(S, "ArgMem: NoModRef, InaccessibleMem: NoModRef, ErrnoMem: "
- "NoModRef, Other: NoModRef");
+ "NoModRef, AARCH64_FPMR: NoModRef, AARCH64_ZA: NoModRef, Other: "
+ "NoModRef");
}
} // namespace
diff --git a/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp b/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
index bc42efa3b2e9c..eb2d4de7e9320 100644
--- a/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
+++ b/llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp
@@ -374,7 +374,19 @@ void CodeGenIntrinsic::setProperty(const Record *R) {
ME &= MemoryEffects::argMemOnly();
else if (R->getName() == "IntrInaccessibleMemOnly")
ME &= MemoryEffects::inaccessibleMemOnly();
- else if (R->getName() == "IntrInaccessibleMemOrArgMemOnly")
+ else if (R->isSubClassOf("IntrInaccessibleReadMemOnly")) {
+ llvm::IRMemLocation Loc = R->getLocationTypeAsInt("Loc");
+ if (ME.onlyAccessTargetMemoryLocation())
+ ME = ME.getWithModRef(Loc, ModRefInfo::Ref);
+ else
+ ME &= MemoryEffects::inaccessibleReadMemOnly(Loc);
+ } else if (R->isSubClassOf("IntrInaccessibleWriteMemOnly")) {
+ llvm::IRMemLocation Loc = R->getLocationTypeAsInt("Loc");
+ if (ME.onlyAccessTargetMemoryLocation())
+ ME = ME.getWithModRef(Loc, ModRefInfo::Mod);
+ else
+ ME &= MemoryEffects::inaccessibleWriteMemOnly(Loc);
+ } else if (R->getName() == "IntrInaccessibleMemOrArgMemOnly")
ME &= MemoryEffects::inaccessibleOrArgMemOnly();
else if (R->getName() == "Commutative")
isCommutative = true;
|
CarolineConcatto
changed the title
|
I am removing from draft, but we are still open to suggestions. Maybe removing from draft to get more attention |
jurahul
reviewed
Jul 24, 2025
| @@ -202,6 +202,8 @@ enum Kind { | |||
| kw_readwrite, | |||
| kw_argmem, | |||
| kw_inaccessiblemem, | |||
| kw_aarch64_fpmr, | |||
There was a problem hiding this comment.
I'll let @nikic comment, but are we really planning to extend LLVM IR syntax with arch specific keywords?
jurahul
reviewed
Jul 24, 2025
| @@ -3102,6 +3102,21 @@ Record::getValueAsListOfDefs(StringRef FieldName) const { | |||
| return Defs; | |||
| } | |||
|
|
|||
| llvm::IRMemLocation Record::getLocationTypeAsInt(StringRef FieldName) const { | |||
There was a problem hiding this comment.
This function does not belong here. It should be moved instead to the specific backend that uses it (intrinsic emitter I am assuming)
jurahul
changed the title
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This patch introduces preliminary support for additional memory locations, such as FPMR and ZA, needed to model AArch64 architectural registers as memory dependencies.
It was a solution suggested in : https://discourse.llvm.org/t/rfc-improving-fpmr-handling-for-fp8-intrinsics-in-llvm/86868/6
Currently, these locations are not yet target-specific. The goal is to enable the compiler to express read/write effects on these resources.
What This Patch Does:
Adds two new memory locations: FPMR and ZA, intended to represent
AArch64-specific inaccessible memory types.
Current Limitations:
These new locations are not yet target-specific in the type-safe sense,
they are globally visible and hardcoded.
There is no mechanism yet to associate a memory location with its
corresponding target (e.g., AArch64 vs RISCV).
No changes are made yet to bitcode serialization, parser support, or alias
analysis behavior.
This patch is not functionally complete — it is a structural prototype to solicit feedback on the direction and I would like some suggestion on how to proceed.