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[clang][CodeGen] Add range metadata for atomic load of boolean type. #131476 #133546

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Merged
merged 11 commits into from
Apr 14, 2025
Merged

[clang][CodeGen] Add range metadata for atomic load of boolean type. #131476 #133546

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4581169
[clang][CodeGen] Added llvm ir pre-commit test.
janagor Mar 28, 2025
852b691
[clang][CodeGen] Added `!range` metadata to atomic load for `bool`.
janagor Mar 28, 2025
e42772b
Updated codestyle.
janagor Mar 29, 2025
c95f16c
Refactored early returns into normal if statement.
janagor Apr 4, 2025
ecc0f40
Reverted adding `range!` metadata from 852b691fac48. Added `isSafeNUW…
janagor Apr 10, 2025
97dc8df
Merge branch 'main' into add_range_metadata
janagor Apr 10, 2025
91142fa
Merge branch 'main' into add_range_metadata
janagor Apr 10, 2025
7e60e8f
fixup! Merge branch 'main' into add_range_metadata
janagor Apr 10, 2025
df9c2bc
Reverted to state before ecc0f4060b91.
janagor Apr 10, 2025
f25e687
Exposed `getRangeForLoadFromType` as a public method to support addin…
janagor Apr 10, 2025
a348252
Created helper function for calling `EmitScalarRangeCheck()` and addi…
janagor Apr 11, 2025
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23 changes: 23 additions & 0 deletions clang/lib/CodeGen/CGAtomic.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -590,6 +590,29 @@ static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *E, Address Dest,
llvm::LoadInst *Load = CGF.Builder.CreateLoad(Ptr);
Load->setAtomic(Order, Scope);
Load->setVolatile(E->isVolatile());

if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
CGF.Builder.CreateStore(Load, Dest);
return;
}

QualType Ty = E->getValueType();
if (!Ty->isBooleanType()) {
CGF.Builder.CreateStore(Load, Dest);
return;
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@efriedma-quic efriedma-quic Apr 2, 2025

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Using an early return like this is weird; just stick a normal if statement around the code that creates the metadata.

}

llvm::MDBuilder MDHelper(CGF.getLLVMContext());
llvm::APInt BooleanMin = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
llvm::APInt BooleanEnd = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);

if (llvm::MDNode *RangeInfo =
MDHelper.createRange(BooleanMin, BooleanEnd)) {
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@efriedma-quic efriedma-quic Apr 2, 2025

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Please refactor the code from CodeGenFunction::EmitLoadOfScalar, instead of reinventing the code to compute the range metadata.

Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
Load->setMetadata(llvm::LLVMContext::MD_noundef,
llvm::MDNode::get(CGF.getLLVMContext(), {}));
}

CGF.Builder.CreateStore(Load, Dest);
return;
}
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11 changes: 11 additions & 0 deletions clang/test/CodeGen/atomic-ops-load.c
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@@ -0,0 +1,11 @@
// RUN: %clang_cc1 -triple riscv64 -O1 -emit-llvm %s -o - | FileCheck %s
#include <stdbool.h>

extern bool t1;
bool test1(void) {
// CHECK-LABEL: define{{.*}} i1 @test1
// CHECK: load atomic i8, ptr @t1 monotonic, align 1, !range ![[$WS_RANGE:[0-9]*]], !noundef !{{[0-9]+}}
// CHECK-NEXT: trunc nuw i8 %{{.*}} to i1
// CHECK-NEXT: ret i1 %{{.*}}
return __atomic_load_n(&t1, __ATOMIC_RELAXED);
}