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[OpenMP] Conditional modifier on lastprivate clause is producing incorrect result in C mode #156004

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Merged
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Sep 11, 2025
Merged

[OpenMP] Conditional modifier on lastprivate clause is producing incorrect result in C mode #156004

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5098dda
Conditional modifier on lastprivate code is producing incorrect resul…
Aug 29, 2025
6c604dd
code formating
Aug 29, 2025
408f70c
formating
chandraghale Aug 29, 2025
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5 changes: 5 additions & 0 deletions clang/lib/CodeGen/CGExprScalar.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5183,6 +5183,11 @@ Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) {
CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS);
}
}
// OpenMP: Handle lastprivate(condition:) in scalar assignment
if (CGF.getLangOpts().OpenMP) {
CGF.CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(CGF,
E->getLHS());
}

// If the result is clearly ignored, return now.
if (Ignore)
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53 changes: 53 additions & 0 deletions clang/test/OpenMP/for_lst_private_codegen_c.c
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@@ -0,0 +1,53 @@
// RUN: %clang_cc1 -verify -x c -triple x86_64-unknown-linux-gnu -fopenmp -fopenmp-version=52 -emit-llvm -o - %s | FileCheck %s
// expected-no-diagnostics

#define N 100
int A[N];

void condlastprivate() {
int x, y, z, k;
x = y = z = k = 0;

#pragma omp parallel for lastprivate(conditional: x,y,z) lastprivate(k)
for (k = 0; k < N; k++) {
if ((k > 2) && (k < 6)) {
x = A[k];
z = A[k] + 111;
} else {
y = A[k] + 222;
}
}
}

int main() {
for (int i = 0; i < N; i++)
A[i] = i;
condlastprivate();
return 0;
}

// CHECK: @.pl_cond.x_[[ID:[0-9]+]].iv = common global i32 0, align 4
// CHECK: @pl_cond.x_[[ID]] = common global i32 0, align 4
// CHECK: @.gomp_critical_user_pl_cond.x_[[ID]].var = common global [8 x i32] zeroinitializer, align 8

// CHECK: @.pl_cond.z_[[ID]].iv = common global i32 0, align 4
// CHECK: @pl_cond.z_[[ID]] = common global i32 0, align 4
// CHECK: @.gomp_critical_user_pl_cond.z_[[ID]].var = common global [8 x i32] zeroinitializer, align 8

// CHECK: @.pl_cond.y_[[ID]].iv = common global i32 0, align 4
// CHECK: @pl_cond.y_[[ID]] = common global i32 0, align 4
// CHECK: @.gomp_critical_user_pl_cond.y_[[ID]].var = common global [8 x i32] zeroinitializer, align 8

// CHECK-LABEL: define internal void @condlastprivate.omp_outlined(
// CHECK: call void @__kmpc_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.x_[[ID]].var)
// CHECK: store i32 %{{[0-9]+}}, ptr @pl_cond.x_[[ID]], align 4
// CHECK: call void @__kmpc_end_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.x_[[ID]].var)

// CHECK: call void @__kmpc_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.z_[[ID]].var)
// CHECK: store i32 %{{[0-9]+}}, ptr @pl_cond.z_[[ID]], align 4
// CHECK: call void @__kmpc_end_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.z_[[ID]].var)

// CHECK: call void @__kmpc_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.y_[[ID]].var)
// CHECK: store i32 %{{[0-9]+}}, ptr @pl_cond.y_[[ID]], align 4
// CHECK: call void @__kmpc_end_critical(ptr @2, {{.*}}, ptr @.gomp_critical_user_pl_cond.y_[[ID]].var)

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