[libc][math][c23] Add setpayloadf16 C23 math function

overmighty · overmighty · commit b841bd813008 · 2024-06-13T19:10:12.000+02:00
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
@@ -543,6 +543,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
+    libc.src.math.setpayloadf16
     libc.src.math.totalorderf16
     libc.src.math.totalordermagf16
     libc.src.math.truncf16
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
@@ -573,6 +573,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
+    libc.src.math.setpayloadf16
     libc.src.math.totalorderf16
     libc.src.math.totalordermagf16
     libc.src.math.truncf16
diff --git a/libc/docs/c23.rst b/libc/docs/c23.rst
@@ -45,7 +45,7 @@ Additions:
   * totalorder* |check|
   * totalordermag* |check|
   * getpayload* |check|
-  * setpayload*
+  * setpayload* |check|
   * iscannonical
   * issignaling
   * issubnormal
diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst
@@ -212,6 +212,8 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | scalbn           | |check|          | |check|         | |check|                |                      | |check|                | 7.12.6.19              | F.10.3.19                  |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
+| setpayload       |                  |                 |                        | |check|              |                        | F.10.13.2              | N/A                        |
++------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | totalorder       |                  |                 |                        | |check|              |                        | F.10.12.1              | N/A                        |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | totalordermag    |                  |                 |                        | |check|              |                        | F.10.12.2              | N/A                        |
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
@@ -717,6 +717,8 @@ def StdC : StandardSpec<"stdc"> {
 
           GuardedFunctionSpec<"getpayloadf16", RetValSpec<Float16Type>, [ArgSpec<Float16Ptr>], "LIBC_TYPES_HAS_FLOAT16">,
 
+          GuardedFunctionSpec<"setpayloadf16", RetValSpec<IntType>, [ArgSpec<Float16Ptr>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
+
           GuardedFunctionSpec<"f16sqrtf", RetValSpec<Float16Type>, [ArgSpec<FloatType>], "LIBC_TYPES_HAS_FLOAT16">,
       ]
   >;
diff --git a/libc/src/__support/FPUtil/BasicOperations.h b/libc/src/__support/FPUtil/BasicOperations.h
@@ -276,6 +276,31 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> getpayload(T x) {
   return T(x_bits.uintval() & (FPBits::FRACTION_MASK >> 1));
 }
 
+template <typename T>
+LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, bool>
+setpayload(T *res, T pl) {
+  using FPBits = FPBits<T>;
+  FPBits pl_bits(pl);
+
+  if (pl_bits.is_zero()) {
+    *res = FPBits::quiet_nan(Sign::POS).get_val();
+    return false;
+  }
+
+  int pl_exp = pl_bits.get_exponent();
+
+  if (pl_bits.is_neg() || pl_exp < 0 || pl_exp >= FPBits::FRACTION_LEN - 1 ||
+      ((pl_bits.get_mantissa() << pl_exp) & FPBits::FRACTION_MASK) != 0) {
+    *res = T(0.0);
+    return true;
+  }
+
+  using StorageType = typename FPBits::StorageType;
+  StorageType v(pl_bits.get_explicit_mantissa() >> (FPBits::SIG_LEN - pl_exp));
+  *res = FPBits::quiet_nan(Sign::POS, v).get_val();
+  return false;
+}
+
 } // namespace fputil
 } // namespace LIBC_NAMESPACE
 
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
@@ -350,6 +350,8 @@ add_math_entrypoint_object(scalbnf)
 add_math_entrypoint_object(scalbnl)
 add_math_entrypoint_object(scalbnf128)
 
+add_math_entrypoint_object(setpayloadf16)
+
 add_math_entrypoint_object(sincos)
 add_math_entrypoint_object(sincosf)
 
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
@@ -3615,6 +3615,19 @@ add_entrypoint_object(
     -O3
 )
 
+add_entrypoint_object(
+  setpayloadf16
+  SRCS
+    setpayloadf16.cpp
+  HDRS
+    ../setpayloadf16.h
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.basic_operations
+  COMPILE_OPTIONS
+    -O3
+)
+
 add_entrypoint_object(
   f16sqrtf
   SRCS
diff --git a/libc/src/math/generic/setpayloadf16.cpp b/libc/src/math/generic/setpayloadf16.cpp
@@ -0,0 +1,19 @@
+//===-- Implementation of setpayloadf16 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/math/setpayloadf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, setpayloadf16, (float16 * res, float16 pl)) {
+  return static_cast<int>(fputil::setpayload(res, pl));
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/setpayloadf16.h b/libc/src/math/setpayloadf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for setpayloadf16 -----------------*- 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_MATH_SETPAYLOADF16_H
+#define LLVM_LIBC_SRC_MATH_SETPAYLOADF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+int setpayloadf16(float16 *res, float16 pl);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_SETPAYLOADF16_H
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
@@ -3560,6 +3560,18 @@ add_fp_unittest(
     libc.src.math.getpayloadf16
 )
 
+add_fp_unittest(
+  setpayloadf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    setpayloadf16_test.cpp
+  HDRS
+    SetPayloadTest.h
+  DEPENDS
+    libc.src.math.setpayloadf16
+)
+
 add_fp_unittest(
   f16sqrtf_test
   SUITE
diff --git a/libc/test/src/math/smoke/SetPayloadTest.h b/libc/test/src/math/smoke/SetPayloadTest.h
@@ -0,0 +1,66 @@
+//===-- Utility class to test different flavors of setpayload ---*- 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 LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
+#define LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+template <typename T>
+class SetPayloadTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(T)
+
+public:
+  typedef int (*SetPayloadFunc)(T *, T);
+
+  void testInvalidPayloads(SetPayloadFunc func) {
+    T res;
+
+    EXPECT_EQ(1, func(&res, T(aNaN)));
+    EXPECT_EQ(1, func(&res, T(neg_aNaN)));
+    EXPECT_EQ(1, func(&res, T(inf)));
+    EXPECT_EQ(1, func(&res, T(neg_inf)));
+    EXPECT_EQ(1, func(&res, T(0.1)));
+    EXPECT_EQ(1, func(&res, T(-0.1)));
+    EXPECT_EQ(1, func(&res, T(-1.0)));
+    EXPECT_EQ(1, func(&res, T(0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(-0x42.1p+0)));
+    EXPECT_EQ(1, func(&res, T(StorageType(1) << (FPBits::FRACTION_LEN - 1))));
+  }
+
+  void testValidPayloads(SetPayloadFunc func) {
+    T res;
+
+    EXPECT_EQ(0, func(&res, T(0.0)));
+    EXPECT_EQ(FPBits(aNaN).uintval(), FPBits(res).uintval());
+    EXPECT_EQ(0, func(&res, T(1.0)));
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 1).uintval(), FPBits(res).uintval());
+    EXPECT_EQ(0, func(&res, T(0x42.0p+0)));
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 0x42).uintval(),
+              FPBits(res).uintval());
+    EXPECT_EQ(0, func(&res, T(0x123.0p+0)));
+    EXPECT_EQ(FPBits::quiet_nan(Sign::POS, 0x123).uintval(),
+              FPBits(res).uintval());
+    EXPECT_EQ(0, func(&res, T(FPBits::FRACTION_MASK >> 1)));
+    EXPECT_EQ(
+        FPBits::quiet_nan(Sign::POS, FPBits::FRACTION_MASK >> 1).uintval(),
+        FPBits(res).uintval());
+  }
+};
+
+#define LIST_SETPAYLOAD_TESTS(T, func)                                         \
+  using LlvmLibcSetPayloadTest = SetPayloadTestTemplate<T>;                    \
+  TEST_F(LlvmLibcSetPayloadTest, InvalidPayloads) {                            \
+    testInvalidPayloads(&func);                                                \
+  }                                                                            \
+  TEST_F(LlvmLibcSetPayloadTest, ValidPayloads) { testValidPayloads(&func); }
+
+#endif // LIBC_TEST_SRC_MATH_SMOKE_SETPAYLOADTEST_H
diff --git a/libc/test/src/math/smoke/setpayloadf16_test.cpp b/libc/test/src/math/smoke/setpayloadf16_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for setpayloadf16 ---------------------------------------===//
+//
+// 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 "SetPayloadTest.h"
+
+#include "src/math/setpayloadf16.h"
+
+LIST_SETPAYLOAD_TESTS(float16, LIBC_NAMESPACE::setpayloadf16)

Original file line number	Diff line number	Diff line change
`@@ -717,6 +717,8 @@ def StdC : StandardSpec<"stdc"> {`
`717`	`717`
`718`	`718`	`GuardedFunctionSpec<"getpayloadf16", RetValSpec<Float16Type>, [ArgSpec<Float16Ptr>], "LIBC_TYPES_HAS_FLOAT16">,`
`719`	`719`
	`720`	`+ GuardedFunctionSpec<"setpayloadf16", RetValSpec<IntType>, [ArgSpec<Float16Ptr>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,`
	`721`	`+`
`720`	`722`	`GuardedFunctionSpec<"f16sqrtf", RetValSpec<Float16Type>, [ArgSpec<FloatType>], "LIBC_TYPES_HAS_FLOAT16">,`
`721`	`723`	`]`
`722`	`724`	`>;`