[libc][c23][fenv] Implement fetestexceptflag #87828

robincaloudis · 2024-04-05T21:09:54Z

Provide C23 fetestexceptflag function according to 7.6.4.6 in the latest revision of the C standard from 2023-04-02.

Closes #87565.

github-actions · 2024-04-05T21:33:21Z

✅ With the latest revision this PR passed the C/C++ code formatter.

llvmbot · 2024-04-09T20:51:54Z

@llvm/pr-subscribers-libc

Author: Robin Caloudis (robincaloudis)

Changes

Closes #87565.

Full diff: https://github.com/llvm/llvm-project/pull/87828.diff

18 Files Affected:

(modified) libc/config/baremetal/arm/entrypoints.txt (+1)
(modified) libc/config/baremetal/riscv/entrypoints.txt (+1)
(modified) libc/config/darwin/arm/entrypoints.txt (+1)
(modified) libc/config/darwin/x86_64/entrypoints.txt (+1)
(modified) libc/config/linux/aarch64/entrypoints.txt (+1)
(modified) libc/config/linux/arm/entrypoints.txt (+1)
(modified) libc/config/linux/riscv/entrypoints.txt (+1)
(modified) libc/config/linux/x86_64/entrypoints.txt (+1)
(modified) libc/config/windows/entrypoints.txt (+1)
(modified) libc/docs/c23.rst (+1-1)
(modified) libc/spec/stdc.td (+5)
(modified) libc/src/fenv/CMakeLists.txt (+13)
(added) libc/src/fenv/fetestexceptflag.cpp (+24)
(added) libc/src/fenv/fetestexceptflag.h (+20)
(modified) libc/test/src/fenv/CMakeLists.txt (+1)
(modified) libc/test/src/fenv/exception_flags_test.cpp (+10-2)
(modified) utils/bazel/llvm-project-overlay/libc/BUILD.bazel (+10)
(modified) utils/bazel/llvm-project-overlay/libc/test/src/fenv/BUILD.bazel (+1)

diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index f33f9430c79205..4e3d1cb9f5337a 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -201,6 +201,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index dad187fa0496d3..7efd9bcd5b3cb8 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -201,6 +201,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/darwin/arm/entrypoints.txt b/libc/config/darwin/arm/entrypoints.txt
index aea2f6d5771e87..e1303265b9ac41 100644
--- a/libc/config/darwin/arm/entrypoints.txt
+++ b/libc/config/darwin/arm/entrypoints.txt
@@ -112,6 +112,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/darwin/x86_64/entrypoints.txt b/libc/config/darwin/x86_64/entrypoints.txt
index 09fe3d7b476870..02912decadcf79 100644
--- a/libc/config/darwin/x86_64/entrypoints.txt
+++ b/libc/config/darwin/x86_64/entrypoints.txt
@@ -106,6 +106,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     # libc.src.fenv.fesetround
     # libc.src.fenv.feraiseexcept
     # libc.src.fenv.fetestexcept
+    # libc.src.fenv.fetestexceptflag
     # libc.src.fenv.feupdateenv
 
     ## Currently disabled for failing tests.
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index f5f5c437685a21..60e5b0be540e71 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -324,6 +324,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
index fca50735d320ba..244587d2b73068 100644
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -192,6 +192,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 71289789158f4b..f54d664a44a33d 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -332,6 +332,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 6bb53cb76220fc..ffff17e8ac7621 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -342,6 +342,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/config/windows/entrypoints.txt b/libc/config/windows/entrypoints.txt
index c46c947bf31354..71216530c4041b 100644
--- a/libc/config/windows/entrypoints.txt
+++ b/libc/config/windows/entrypoints.txt
@@ -110,6 +110,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.fenv.fesetround
     libc.src.fenv.feraiseexcept
     libc.src.fenv.fetestexcept
+    libc.src.fenv.fetestexceptflag
     libc.src.fenv.feupdateenv
 
     # math.h entrypoints
diff --git a/libc/docs/c23.rst b/libc/docs/c23.rst
index 4138c9d7104f33..44724fe1660cbe 100644
--- a/libc/docs/c23.rst
+++ b/libc/docs/c23.rst
@@ -21,7 +21,7 @@ Additions:
 * fenv.h
 
   * fesetexcept |check|
-  * fetestexceptflag
+  * fetestexceptflag |check|
   * fegetmode
   * fesetmode
 * math.h
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index 63d0449867114d..01aa7c70b3b9df 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -149,6 +149,11 @@ def StdC : StandardSpec<"stdc"> {
               RetValSpec<IntType>,
               [ArgSpec<IntType>]
           >,
+          FunctionSpec<
+              "fetestexceptflag",
+              RetValSpec<IntType>,
+              [ArgSpec<ConstFExceptTPtr>, ArgSpec<IntType>]
+          >,
           FunctionSpec<
               "feraiseexcept",
               RetValSpec<IntType>,
diff --git a/libc/src/fenv/CMakeLists.txt b/libc/src/fenv/CMakeLists.txt
index d2f90d3d007a1b..8c436a7a934b8a 100644
--- a/libc/src/fenv/CMakeLists.txt
+++ b/libc/src/fenv/CMakeLists.txt
@@ -63,6 +63,19 @@ add_entrypoint_object(
     -O2
 )
 
+add_entrypoint_object(
+  fetestexceptflag
+  SRCS
+    fetestexceptflag.cpp
+  HDRS
+    fetestexceptflag.h
+  DEPENDS
+    libc.include.fenv
+    libc.src.__support.FPUtil.fenv_impl
+  COMPILE_OPTIONS
+    -O2
+)
+
 add_entrypoint_object(
   fegetenv
   SRCS
diff --git a/libc/src/fenv/fetestexceptflag.cpp b/libc/src/fenv/fetestexceptflag.cpp
new file mode 100644
index 00000000000000..6fee0f3a36bcf7
--- /dev/null
+++ b/libc/src/fenv/fetestexceptflag.cpp
@@ -0,0 +1,24 @@
+//===-- Implementation of fetestexceptflag 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/fenv/fetestexceptflag.h"
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/common.h"
+
+#include <fenv.h>
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, fetestexceptflag,
+                   (const fexcept_t *flagp, int excepts)) {
+  static_assert(sizeof(int) >= sizeof(fexcept_t),
+                "fexcept_t value cannot fit in an int value.");
+  return *flagp | fputil::test_except(excepts);
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/fenv/fetestexceptflag.h b/libc/src/fenv/fetestexceptflag.h
new file mode 100644
index 00000000000000..d9f1a990a2a0f5
--- /dev/null
+++ b/libc/src/fenv/fetestexceptflag.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for fetestexceptflag --------------*- 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_FENV_FETESTEXCEPTFLAG_H
+#define LLVM_LIBC_SRC_FENV_FETESTEXCEPTFLAG_H
+
+#include <fenv.h>
+
+namespace LIBC_NAMESPACE {
+
+int fetestexceptflag(const fexcept_t *, int excepts);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_FENV_FETESTEXCEPTFLAG_H
diff --git a/libc/test/src/fenv/CMakeLists.txt b/libc/test/src/fenv/CMakeLists.txt
index 7e456b9a922fb9..b18fc914831bed 100644
--- a/libc/test/src/fenv/CMakeLists.txt
+++ b/libc/test/src/fenv/CMakeLists.txt
@@ -48,6 +48,7 @@ add_libc_unittest(
   DEPENDS
     libc.src.fenv.fegetexceptflag
     libc.src.fenv.fesetexceptflag
+    libc.src.fenv.fetestexceptflag
     libc.src.__support.FPUtil.fenv_impl
 )
 
diff --git a/libc/test/src/fenv/exception_flags_test.cpp b/libc/test/src/fenv/exception_flags_test.cpp
index 434adc06b1a36a..87ec974d16ddf0 100644
--- a/libc/test/src/fenv/exception_flags_test.cpp
+++ b/libc/test/src/fenv/exception_flags_test.cpp
@@ -1,4 +1,5 @@
-//===-- Unittests for fegetexceptflag and fesetexceptflag -----------------===//
+//===-- Unittests for fegetexceptflag, fesetexceptflag and ----------------===//
+//===-- fetestexceptflag --------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -8,13 +9,14 @@
 
 #include "src/fenv/fegetexceptflag.h"
 #include "src/fenv/fesetexceptflag.h"
+#include "src/fenv/fetestexceptflag.h"
 
 #include "src/__support/FPUtil/FEnvImpl.h"
 #include "test/UnitTest/Test.h"
 
 #include <fenv.h>
 
-TEST(LlvmLibcFenvTest, GetExceptFlagAndSetExceptFlag) {
+TEST(LlvmLibcFenvTest, GetExceptFlagAndSetExceptFlagAndTestExceptFlag) {
   // We will disable all exceptions to prevent invocation of the exception
   // handler.
   LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);
@@ -40,6 +42,11 @@ TEST(LlvmLibcFenvTest, GetExceptFlagAndSetExceptFlag) {
     ASSERT_EQ(LIBC_NAMESPACE::fesetexceptflag(&eflags, FE_ALL_EXCEPT), 0);
     ASSERT_NE(LIBC_NAMESPACE::fputil::test_except(FE_ALL_EXCEPT) & e, 0);
 
+    // Exception flags are exactly the flags corresponding to the previously
+    // raised exception.
+    ASSERT_EQ(LIBC_NAMESPACE::fetestexceptflag(&eflags, FE_ALL_EXCEPT),
+              LIBC_NAMESPACE::fputil::test_except(FE_ALL_EXCEPT));
+
     // Cleanup. We clear all excepts as raising excepts like FE_OVERFLOW
     // can also raise FE_INEXACT.
     LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
@@ -49,6 +56,7 @@ TEST(LlvmLibcFenvTest, GetExceptFlagAndSetExceptFlag) {
   LIBC_NAMESPACE::fputil::raise_except(FE_INVALID);
   fexcept_t eflags;
   LIBC_NAMESPACE::fegetexceptflag(&eflags, FE_ALL_EXCEPT);
+  ASSERT_EQ(LIBC_NAMESPACE::fetestexceptflag(&eflags, FE_ALL_EXCEPT), FE_INVALID);
   // Clear all exceptions and raise two other exceptions.
   LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
   LIBC_NAMESPACE::fputil::raise_except(FE_OVERFLOW | FE_INEXACT);
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 13b290c4bd2b8c..44b2396a4fa397 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -1094,6 +1094,16 @@ libc_function(
     ],
 )
 
+libc_function(
+    name = "fetestexceptflag",
+    srcs = ["src/fenv/fetestexceptflag.cpp"],
+    hdrs = ["src/fenv/fetestexceptflag.h"],
+    deps = [
+        ":__support_common",
+        ":__support_fputil_fenv_impl",
+    ],
+)
+
 libc_function(
     name = "feclearexcept",
     srcs = ["src/fenv/feclearexcept.cpp"],
diff --git a/utils/bazel/llvm-project-overlay/libc/test/src/fenv/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/src/fenv/BUILD.bazel
index 2a268ae227fba8..d5e3fc763b6ed3 100644
--- a/utils/bazel/llvm-project-overlay/libc/test/src/fenv/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/test/src/fenv/BUILD.bazel
@@ -71,6 +71,7 @@ libc_test(
     libc_function_deps = [
         "//libc:fegetexceptflag",
         "//libc:fesetexceptflag",
+        "//libc:fetestexceptflag",
     ],
     deps = [
         "//libc:__support_fputil_fenv_impl",

nickdesaulniers

Do you mind regenerating the docs for fenv.h?

./libc/utils/docgen/docgen.py fenv.h > libc/docs/fenv.rst

And thanks for the patch!

libc/test/src/fenv/exception_flags_test.cpp

libc/src/fenv/fetestexceptflag.h

robincaloudis · 2024-04-14T18:21:37Z

Thanks for the review, @nickdesaulniers and @lntue. I fully agree on the things you pointed out and made the corresponding changes. As #88467 is already approved, let's wait until it is merged and use #include "hdr/types/fexcept_t.h" instead of #include <fenv.h>.

robincaloudis · 2024-04-15T21:14:13Z

All done. Do you mind to take another look? Thanks!

libc/test/src/fenv/exception_flags_test.cpp

nickdesaulniers

Will merge once presubmit returns back green! Thanks for the patch!

robincaloudis · 2024-04-16T21:58:14Z

Sounds good. Thank you!

robincaloudis force-pushed the rc-impl-fetestexceptflag branch 2 times, most recently from 03bf0f1 to d9f362f Compare April 5, 2024 21:30

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from d9f362f to a5a0168 Compare April 9, 2024 20:49

robincaloudis marked this pull request as ready for review April 9, 2024 20:51

robincaloudis requested a review from rupprecht as a code owner April 9, 2024 20:51

llvmbot added libc bazel "Peripheral" support tier build system: utils/bazel labels Apr 9, 2024

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from a5a0168 to 530f0df Compare April 9, 2024 20:53

robincaloudis mentioned this pull request Apr 9, 2024

[libc][c23][fenv] implement fetestexceptflag #87565

Closed

nickdesaulniers self-requested a review April 12, 2024 16:41

nickdesaulniers reviewed Apr 12, 2024

View reviewed changes

libc/test/src/fenv/exception_flags_test.cpp Outdated Show resolved Hide resolved

libc/test/src/fenv/exception_flags_test.cpp Outdated Show resolved Hide resolved

nickdesaulniers requested a review from lntue April 12, 2024 16:53

lntue reviewed Apr 12, 2024

View reviewed changes

libc/src/fenv/fetestexceptflag.h Outdated Show resolved Hide resolved

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from 530f0df to 755443b Compare April 14, 2024 18:09

robincaloudis requested review from lntue and nickdesaulniers April 14, 2024 18:22

robincaloudis added 4 commits April 15, 2024 21:26

[libc][c23][fenv] Implement fetestexceptflag

375d3d0

Shorten description

32a2e2a

Regenerate docs

a25a77a

Use proxy headers

aa017d2

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from 755443b to aa017d2 Compare April 15, 2024 19:55

nickdesaulniers reviewed Apr 15, 2024

View reviewed changes

libc/test/src/fenv/exception_flags_test.cpp Show resolved Hide resolved

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from 2ad3f97 to 481cea3 Compare April 16, 2024 19:13

nickdesaulniers reviewed Apr 16, 2024

View reviewed changes

libc/test/src/fenv/exception_flags_test.cpp Show resolved Hide resolved

Verify that other exceptions are set

d319a2a

robincaloudis force-pushed the rc-impl-fetestexceptflag branch from 481cea3 to d319a2a Compare April 16, 2024 21:48

nickdesaulniers approved these changes Apr 16, 2024

View reviewed changes

nickdesaulniers merged commit b854a23 into llvm:main Apr 17, 2024

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[libc][c23][fenv] Implement fetestexceptflag #87828

[libc][c23][fenv] Implement fetestexceptflag #87828

Uh oh!

robincaloudis commented Apr 5, 2024 •

edited

Loading

Uh oh!

github-actions bot commented Apr 5, 2024 •

edited

Loading

Uh oh!

llvmbot commented Apr 9, 2024

Uh oh!

nickdesaulniers left a comment •

edited

Loading

Uh oh!

Uh oh!

Uh oh!

Uh oh!

robincaloudis commented Apr 14, 2024

Uh oh!

robincaloudis commented Apr 15, 2024

Uh oh!

Uh oh!

Uh oh!

nickdesaulniers left a comment

Uh oh!

robincaloudis commented Apr 16, 2024

Uh oh!

Uh oh!

[libc][c23][fenv] Implement fetestexceptflag #87828

[libc][c23][fenv] Implement fetestexceptflag #87828

Uh oh!

Conversation

robincaloudis commented Apr 5, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions bot commented Apr 5, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

llvmbot commented Apr 9, 2024

Uh oh!

nickdesaulniers left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

robincaloudis commented Apr 14, 2024

Uh oh!

robincaloudis commented Apr 15, 2024

Uh oh!

Uh oh!

Uh oh!

nickdesaulniers left a comment

Choose a reason for hiding this comment

Uh oh!

robincaloudis commented Apr 16, 2024

Uh oh!

Uh oh!

robincaloudis commented Apr 5, 2024 •

edited

Loading

github-actions bot commented Apr 5, 2024 •

edited

Loading

nickdesaulniers left a comment •

edited

Loading