[libc-commits] [libc] [libc][complex] Add cargf and carg functions to libc complex math (PR #204087)

via libc-commits libc-commits at lists.llvm.org
Tue Jun 16 01:46:34 PDT 2026


llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: jinge90

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/204087.diff


15 Files Affected:

- (modified) libc/config/linux/aarch64/entrypoints.txt (+2) 
- (modified) libc/config/linux/arm/entrypoints.txt (+2) 
- (modified) libc/config/linux/riscv/entrypoints.txt (+2) 
- (modified) libc/config/linux/x86_64/entrypoints.txt (+2) 
- (modified) libc/include/complex.yaml (+12) 
- (modified) libc/src/complex/CMakeLists.txt (+4) 
- (added) libc/src/complex/carg.h (+20) 
- (added) libc/src/complex/cargf.h (+20) 
- (modified) libc/src/complex/generic/CMakeLists.txt (+25) 
- (added) libc/src/complex/generic/carg.cpp (+22) 
- (added) libc/src/complex/generic/cargf.cpp (+22) 
- (added) libc/test/src/complex/CArgTest.h (+102) 
- (modified) libc/test/src/complex/CMakeLists.txt (+20) 
- (added) libc/test/src/complex/carg_test.cpp (+13) 
- (added) libc/test/src/complex/cargf_test.cpp (+13) 


``````````diff
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 5cddf3dc89799..a5785620bb4c2 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -440,6 +440,8 @@ endif()
 
 set(TARGET_LIBM_ENTRYPOINTS
     # complex.h entrypoints
+    libc.src.complex.carg
+    libc.src.complex.cargf
     libc.src.complex.creal
     libc.src.complex.crealf
     libc.src.complex.creall
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
index c4ac53c4925a3..d2a75f0e1c739 100644
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -236,6 +236,8 @@ endif()
 
 set(TARGET_LIBM_ENTRYPOINTS
     # complex.h entrypoints
+    libc.src.complex.carg
+    libc.src.complex.cargf
     libc.src.complex.creal
     libc.src.complex.crealf
     libc.src.complex.creall
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index a57efbb8e464d..491e6df66162c 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -444,6 +444,8 @@ endif()
 
 set(TARGET_LIBM_ENTRYPOINTS
     # complex.h entrypoints
+    libc.src.complex.carg
+    libc.src.complex.cargf
     libc.src.complex.creal
     libc.src.complex.crealf
     libc.src.complex.creall
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index ce88a6749d9dc..1ca5fab6da216 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -510,6 +510,8 @@ endif()
 
 set(TARGET_LIBM_ENTRYPOINTS
     # complex.h entrypoints
+    libc.src.complex.carg
+    libc.src.complex.cargf
     libc.src.complex.creal
     libc.src.complex.crealf
     libc.src.complex.creall
diff --git a/libc/include/complex.yaml b/libc/include/complex.yaml
index 4db42be6082da..29799799d2e6b 100644
--- a/libc/include/complex.yaml
+++ b/libc/include/complex.yaml
@@ -21,6 +21,18 @@ types:
 enums: []
 objects: []
 functions:
+  - name: carg
+    standards:
+      - stdc
+    return_type: double
+    arguments:
+      - type: _Complex double
+  - name: cargf
+    standards:
+      - stdc
+    return_type: float
+    arguments:
+      - type: _Complex float
   - name: cimag
     standards:
       - stdc
diff --git a/libc/src/complex/CMakeLists.txt b/libc/src/complex/CMakeLists.txt
index bc66a5445d727..1ebc1e8ac6141 100644
--- a/libc/src/complex/CMakeLists.txt
+++ b/libc/src/complex/CMakeLists.txt
@@ -36,3 +36,7 @@ add_complex_entrypoint_object(cprojf)
 add_complex_entrypoint_object(cprojl)
 add_complex_entrypoint_object(cprojf16)
 add_complex_entrypoint_object(cprojf128)
+
+add_complex_entrypoint_object(carg)
+add_complex_entrypoint_object(cargf)
+
diff --git a/libc/src/complex/carg.h b/libc/src/complex/carg.h
new file mode 100644
index 0000000000000..3dfaf592d38ce
--- /dev/null
+++ b/libc/src/complex/carg.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for carg --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CARG_H
+#define LLVM_LIBC_SRC_COMPLEX_CARG_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+double carg(_Complex double x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CARG_H
diff --git a/libc/src/complex/cargf.h b/libc/src/complex/cargf.h
new file mode 100644
index 0000000000000..24d3cc0684fc8
--- /dev/null
+++ b/libc/src/complex/cargf.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for cargf -------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CARGF_H
+#define LLVM_LIBC_SRC_COMPLEX_CARGF_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+float cargf(_Complex float x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CARGF_H
diff --git a/libc/src/complex/generic/CMakeLists.txt b/libc/src/complex/generic/CMakeLists.txt
index f1c21e4ed7271..f9e149c9c0230 100644
--- a/libc/src/complex/generic/CMakeLists.txt
+++ b/libc/src/complex/generic/CMakeLists.txt
@@ -1,3 +1,28 @@
+add_entrypoint_object(
+  carg
+  SRCS
+    carg.cpp
+  HDRS
+    ../carg.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+    libc.src.__support.math.atan2
+)
+
+add_entrypoint_object(
+  cargf
+  SRCS
+    cargf.cpp
+  HDRS
+    ../cargf.h
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+    libc.src.__support.math.atan2f
+)
+
+
 add_entrypoint_object(
   cproj
   SRCS
diff --git a/libc/src/complex/generic/carg.cpp b/libc/src/complex/generic/carg.cpp
new file mode 100644
index 0000000000000..c0f731d55da1e
--- /dev/null
+++ b/libc/src/complex/generic/carg.cpp
@@ -0,0 +1,22 @@
+//===-- Implementation of carg function -----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/carg.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+#include "src/__support/math/atan2.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(double, carg, (_Complex double x)) {
+  Complex<double> x_c = cpp::bit_cast<Complex<double>>(x);
+  return math::atan2(x_c.imag, x_c.real);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/complex/generic/cargf.cpp b/libc/src/complex/generic/cargf.cpp
new file mode 100644
index 0000000000000..7497192d8a147
--- /dev/null
+++ b/libc/src/complex/generic/cargf.cpp
@@ -0,0 +1,22 @@
+//===-- Implementation of cargf function ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/cargf.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+#include "src/__support/math/atan2f.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(float, cargf, (_Complex float x)) {
+  Complex<float> x_c = cpp::bit_cast<Complex<float>>(x);
+  return math::atan2f(x_c.imag, x_c.real);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/complex/CArgTest.h b/libc/test/src/complex/CArgTest.h
new file mode 100644
index 0000000000000..890b3f280d9dc
--- /dev/null
+++ b/libc/test/src/complex/CArgTest.h
@@ -0,0 +1,102 @@
+//===-- Utility class to test different flavors of carg ---------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TEST_SRC_COMPLEX_CARGTEST_H
+#define LLVM_LIBC_TEST_SRC_COMPLEX_CARGTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+#include "hdr/math_macros.h"
+
+template <typename CFPT, typename FPT>
+class CArgTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(FPT)
+
+public:
+  typedef FPT (*CArgFunc)(CFPT);
+
+  void testZeroValues(CArgFunc func) {
+    EXPECT_FP_EQ(func(CFPT{0.0, 0.0}), zero);
+    EXPECT_FP_EQ(func(CFPT{0.0, -0.0}), neg_zero);
+    EXPECT_FP_EQ(func(CFPT{1.0, 0.0}), zero);
+    EXPECT_FP_EQ(func(CFPT{128.0, 0.0}), zero);
+    EXPECT_FP_EQ(func(CFPT{1.0, -0.0}), neg_zero);
+  }
+
+  void testInfinityValues(CArgFunc func) {
+    // carg(+inf + yi) = +0 for finite y > 0
+    EXPECT_FP_EQ(zero, func(CFPT{inf, 1.0}));
+    EXPECT_FP_EQ(zero, func(CFPT{inf, 256.0}));
+    // carg(+inf - yi) = -0 for finite y > 0
+    EXPECT_FP_EQ(neg_zero, func(CFPT{inf, -1.0}));
+    EXPECT_FP_EQ(neg_zero, func(CFPT{inf, -1024.0}));
+    // carg(+inf + 0i) = +0
+    EXPECT_FP_EQ(zero, func(CFPT{inf, 0.0}));
+    // carg(+inf - 0i) = -0
+    EXPECT_FP_EQ(neg_zero, func(CFPT{inf, -0.0}));
+
+    // carg(-inf + yi) = +pi for finite y > 0
+    EXPECT_FP_EQ(FPT(M_PI), func(CFPT{neg_inf, 1.0}));
+    EXPECT_FP_EQ(FPT(M_PI), func(CFPT{neg_inf, 64.0}));
+    // carg(-inf - yi) = -pi for finite y > 0
+    EXPECT_FP_EQ(FPT(-M_PI), func(CFPT{neg_inf,-1.0}));
+    EXPECT_FP_EQ(FPT(-M_PI), func(CFPT{neg_inf, -512.0}));
+    // carg(-inf + 0i) = +pi
+    EXPECT_FP_EQ(FPT(M_PI), func(CFPT{neg_inf, 0.0}));
+    // carg(-inf - 0i) = -pi
+    EXPECT_FP_EQ(FPT(-M_PI), func(CFPT{neg_inf, -0.0}));
+
+    // carg(x + inf*i) = +pi/2 for finite x
+    EXPECT_FP_EQ(FPT(M_PI_2), func(CFPT{1.0, inf}));
+    EXPECT_FP_EQ(FPT(M_PI_2), func(CFPT{-1.0, inf}));
+    EXPECT_FP_EQ(FPT(M_PI_2), func(CFPT{0.0, inf}));
+    EXPECT_FP_EQ(FPT(M_PI_2), func(CFPT{4.0, inf}));
+    // carg(x - inf*i) = -pi/2 for finite x
+    EXPECT_FP_EQ(FPT(-M_PI_2), func(CFPT{1.0, neg_inf}));
+    EXPECT_FP_EQ(FPT(-M_PI_2), func(CFPT{-1.0, neg_inf}));
+    EXPECT_FP_EQ(FPT(-M_PI_2), func(CFPT{0.0, neg_inf}));
+    EXPECT_FP_EQ(FPT(-M_PI_2), func(CFPT{4.0, neg_inf}));
+  }
+
+  void testNaNValues(CArgFunc func) {
+    // carg(NaN + yi) = NaN for finite y
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, 0.0}));
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, 1.0}));
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, -1.0}));
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, 512.0}));
+
+    // carg(x + NaN*i) = NaN for finite x
+    EXPECT_FP_IS_NAN(func(CFPT{0.0, aNaN}));
+    EXPECT_FP_IS_NAN(func(CFPT{1.0, aNaN}));
+    EXPECT_FP_IS_NAN(func(CFPT{-1.0, aNaN}));
+    EXPECT_FP_IS_NAN(func(CFPT{4.0, aNaN}));
+
+    // carg(NaN + NaN*i) = NaN
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, aNaN}));
+
+    // carg(+inf + NaN*i) = NaN
+    EXPECT_FP_IS_NAN(func(CFPT{inf, aNaN}));
+    // carg(-inf + NaN*i) = NaN
+    EXPECT_FP_IS_NAN(func(CFPT{neg_inf, aNaN}));
+    // carg(NaN + inf*i) = NaN
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, inf}));
+    // carg(NaN - inf*i) = NaN
+    EXPECT_FP_IS_NAN(func(CFPT{aNaN, neg_inf}));
+  }
+};
+
+#define LIST_CARG_TESTS(U, T, func)                                            \
+  using LlvmLibcCArgTest = CArgTest<U, T>;                                     \
+  TEST_F(LlvmLibcCArgTest, ZeroValues) { testZeroValues(&func); }              \
+  TEST_F(LlvmLibcCArgTest, InfinityValues) { testInfinityValues(&func); }      \
+  TEST_F(LlvmLibcCArgTest, NaNValues) { testNaNValues(&func); }
+
+#endif // LLVM_LIBC_TEST_SRC_COMPLEX_CARGTEST_H
diff --git a/libc/test/src/complex/CMakeLists.txt b/libc/test/src/complex/CMakeLists.txt
index efd1ede63eca5..fda44fa2f1422 100644
--- a/libc/test/src/complex/CMakeLists.txt
+++ b/libc/test/src/complex/CMakeLists.txt
@@ -1,5 +1,25 @@
 add_custom_target(libc-complex-unittests)
 
+add_fp_unittest(
+  carg_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    carg_test.cpp
+  DEPENDS
+    libc.src.complex.carg
+)
+
+add_fp_unittest(
+  cargf_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    cargf_test.cpp
+  DEPENDS
+    libc.src.complex.cargf
+)
+
 add_fp_unittest(
   conj_test
   SUITE
diff --git a/libc/test/src/complex/carg_test.cpp b/libc/test/src/complex/carg_test.cpp
new file mode 100644
index 0000000000000..f6fd1d7df5e31
--- /dev/null
+++ b/libc/test/src/complex/carg_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for carg -------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CArgTest.h"
+
+#include "src/complex/carg.h"
+
+LIST_CARG_TESTS(_Complex double, double, LIBC_NAMESPACE::carg)
diff --git a/libc/test/src/complex/cargf_test.cpp b/libc/test/src/complex/cargf_test.cpp
new file mode 100644
index 0000000000000..1c47be9c644ae
--- /dev/null
+++ b/libc/test/src/complex/cargf_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for cargf ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CArgTest.h"
+
+#include "src/complex/cargf.h"
+
+LIST_CARG_TESTS(_Complex float, float, LIBC_NAMESPACE::cargf)

``````````

</details>


https://github.com/llvm/llvm-project/pull/204087


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