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-rw-r--r--libc/src/__support/OSUtil/linux/auxv.h3
-rw-r--r--libc/src/__support/OSUtil/linux/syscall.h14
-rw-r--r--libc/src/__support/math/CMakeLists.txt44
-rw-r--r--libc/src/__support/math/rsqrtf.h71
-rw-r--r--libc/src/__support/threads/linux/thread.cpp2
-rw-r--r--libc/src/math/CMakeLists.txt1
-rw-r--r--libc/src/math/generic/CMakeLists.txt10
-rw-r--r--libc/src/math/generic/rsqrtf.cpp16
-rw-r--r--libc/src/math/rsqrtf.h20
-rw-r--r--libc/src/sys/mman/linux/mmap.cpp2
10 files changed, 164 insertions, 19 deletions
diff --git a/libc/src/__support/OSUtil/linux/auxv.h b/libc/src/__support/OSUtil/linux/auxv.h
index 894868a..9c07c54 100644
--- a/libc/src/__support/OSUtil/linux/auxv.h
+++ b/libc/src/__support/OSUtil/linux/auxv.h
@@ -16,6 +16,7 @@
#include <linux/auxvec.h> // For AT_ macros
#include <linux/mman.h> // For mmap flags
+#include <linux/param.h> // For EXEC_PAGESIZE
#include <linux/prctl.h> // For prctl
#include <sys/syscall.h> // For syscall numbers
@@ -90,7 +91,7 @@ LIBC_INLINE void Vector::fallback_initialize_unsync() {
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
// We do not proceed if mmap fails.
- if (mmap_ret <= 0)
+ if (!linux_utils::is_valid_mmap(mmap_ret))
return;
// Initialize the auxv array with AT_NULL entries.
diff --git a/libc/src/__support/OSUtil/linux/syscall.h b/libc/src/__support/OSUtil/linux/syscall.h
index 24e0fca..0e25618 100644
--- a/libc/src/__support/OSUtil/linux/syscall.h
+++ b/libc/src/__support/OSUtil/linux/syscall.h
@@ -12,6 +12,7 @@
#include "src/__support/CPP/bit.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
+#include "src/__support/macros/optimization.h"
#include "src/__support/macros/properties/architectures.h"
#ifdef LIBC_TARGET_ARCH_IS_X86_32
@@ -34,6 +35,19 @@ LIBC_INLINE R syscall_impl(long __number, Ts... ts) {
return cpp::bit_or_static_cast<R>(syscall_impl(__number, (long)ts...));
}
+// Linux-specific function for checking
+namespace linux_utils {
+LIBC_INLINE_VAR constexpr unsigned long MAX_ERRNO = 4095;
+// Ideally, this should be defined using PAGE_OFFSET
+// However, that is a configurable parameter. We mimic kernel's behavior
+// by checking against MAX_ERRNO.
+template <typename PointerLike>
+LIBC_INLINE constexpr bool is_valid_mmap(PointerLike ptr) {
+ long addr = cpp::bit_cast<long>(ptr);
+ return LIBC_LIKELY(addr > 0 || addr < -static_cast<long>(MAX_ERRNO));
+}
+} // namespace linux_utils
+
} // namespace LIBC_NAMESPACE_DECL
#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_SYSCALL_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index 203ebb4..61253de 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -109,22 +109,6 @@ add_header_library(
libc.src.__support.macros.properties.types
)
-
-add_header_library(
- rsqrtf16
- HDRS
- rsqrtf16.h
- DEPENDS
- libc.src.__support.FPUtil.cast
- libc.src.__support.FPUtil.fenv_impl
- libc.src.__support.FPUtil.fp_bits
- libc.src.__support.FPUtil.multiply_add
- libc.src.__support.FPUtil.polyeval
- libc.src.__support.FPUtil.manipulation_functions
- libc.src.__support.macros.optimization
- libc.src.__support.macros.properties.types
-)
-
add_header_library(
asin_utils
HDRS
@@ -867,6 +851,34 @@ add_header_library(
)
add_header_library(
+ rsqrtf
+ HDRS
+ rsqrtf.h
+ DEPENDS
+ libc.hdr.errno_macros
+ libc.hdr.fenv_macros
+ libc.src.__support.FPUtil.cast
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.sqrt
+ libc.src.__support.macros.optimization
+)
+
+add_header_library(
+ rsqrtf16
+ HDRS
+ rsqrtf16.h
+ DEPENDS
+ libc.hdr.errno_macros
+ libc.hdr.fenv_macros
+ libc.src.__support.FPUtil.cast
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.sqrt
+ libc.src.__support.macros.optimization
+)
+
+add_header_library(
sincos_eval
HDRS
sincos_eval.h
diff --git a/libc/src/__support/math/rsqrtf.h b/libc/src/__support/math/rsqrtf.h
new file mode 100644
index 0000000..5da1e73
--- /dev/null
+++ b/libc/src/__support/math/rsqrtf.h
@@ -0,0 +1,71 @@
+//===-- Implementation header for rsqrtf ------------------------*- 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___SUPPORT_MATH_RSQRTF_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_RSQRTF_H
+
+#include "hdr/errno_macros.h"
+#include "hdr/fenv_macros.h"
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/cast.h"
+#include "src/__support/FPUtil/sqrt.h"
+#include "src/__support/macros/optimization.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace math {
+
+LIBC_INLINE static constexpr float rsqrtf(float x) {
+ using FPBits = fputil::FPBits<float>;
+ FPBits xbits(x);
+
+ uint32_t x_u = xbits.uintval();
+ uint32_t x_abs = x_u & 0x7fff'ffffU;
+
+ constexpr uint32_t INF_BITS = FPBits::inf().uintval();
+
+ // x is 0, inf/nan, or negative.
+ if (LIBC_UNLIKELY(x_u == 0 || x_u >= INF_BITS)) {
+ // x is NaN
+ if (x_abs > INF_BITS) {
+ if (xbits.is_signaling_nan()) {
+ fputil::raise_except_if_required(FE_INVALID);
+ return FPBits::quiet_nan().get_val();
+ }
+ return x;
+ }
+
+ // |x| = 0
+ if (x_abs == 0) {
+ fputil::raise_except_if_required(FE_DIVBYZERO);
+ fputil::set_errno_if_required(ERANGE);
+ return FPBits::inf(xbits.sign()).get_val();
+ }
+
+ // -inf <= x < 0
+ if (x_u > 0x7fff'ffffU) {
+ fputil::raise_except_if_required(FE_INVALID);
+ fputil::set_errno_if_required(EDOM);
+ return FPBits::quiet_nan().get_val();
+ }
+
+ // x = +inf => rsqrt(x) = 0
+ return FPBits::zero(xbits.sign()).get_val();
+ }
+
+ // TODO: add float based approximation when
+ // LIBC_TARGET_CPU_HAS_FPU_DOUBLE is not defined
+ double result = 1.0 / fputil::sqrt<double>(fputil::cast<double>(x));
+
+ return fputil::cast<float>(result);
+}
+
+} // namespace math
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_RSQRTF_H
diff --git a/libc/src/__support/threads/linux/thread.cpp b/libc/src/__support/threads/linux/thread.cpp
index d9e479ee..4f1e911 100644
--- a/libc/src/__support/threads/linux/thread.cpp
+++ b/libc/src/__support/threads/linux/thread.cpp
@@ -100,7 +100,7 @@ LIBC_INLINE ErrorOr<void *> alloc_stack(size_t stacksize, size_t guardsize) {
-1, // Not backed by any file
0 // No offset
);
- if (mmap_result < 0 && (uintptr_t(mmap_result) >= UINTPTR_MAX - size))
+ if (!linux_utils::is_valid_mmap(mmap_result))
return Error{int(-mmap_result)};
if (guardsize) {
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index 3c7e99f..e37e22f 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -517,6 +517,7 @@ add_math_entrypoint_object(roundevenf16)
add_math_entrypoint_object(roundevenf128)
add_math_entrypoint_object(roundevenbf16)
+add_math_entrypoint_object(rsqrtf)
add_math_entrypoint_object(rsqrtf16)
add_math_entrypoint_object(scalbln)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index 5738fe8..55f4aaf 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -989,6 +989,16 @@ add_entrypoint_object(
)
add_entrypoint_object(
+ rsqrtf
+ SRCS
+ rsqrtf.cpp
+ HDRS
+ ../rsqrtf.h
+ DEPENDS
+ libc.src.__support.math.rsqrtf
+)
+
+add_entrypoint_object(
rsqrtf16
SRCS
rsqrtf16.cpp
diff --git a/libc/src/math/generic/rsqrtf.cpp b/libc/src/math/generic/rsqrtf.cpp
new file mode 100644
index 0000000..6a38fa7
--- /dev/null
+++ b/libc/src/math/generic/rsqrtf.cpp
@@ -0,0 +1,16 @@
+//===-- Single-precision rsqrt 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/rsqrtf.h"
+#include "src/__support/math/rsqrtf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(float, rsqrtf, (float x)) { return math::rsqrtf(x); }
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/math/rsqrtf.h b/libc/src/math/rsqrtf.h
new file mode 100644
index 0000000..bc55904
--- /dev/null
+++ b/libc/src/math/rsqrtf.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for rsqrtf ------------------------*- 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_RSQRTF_H
+#define LLVM_LIBC_SRC_MATH_RSQRTF_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+float rsqrtf(float x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_MATH_RSQRTF_H
diff --git a/libc/src/sys/mman/linux/mmap.cpp b/libc/src/sys/mman/linux/mmap.cpp
index 33f9fe8..76a6611 100644
--- a/libc/src/sys/mman/linux/mmap.cpp
+++ b/libc/src/sys/mman/linux/mmap.cpp
@@ -56,7 +56,7 @@ LLVM_LIBC_FUNCTION(void *, mmap,
// However, since a valid return address cannot be within the last page, a
// return value corresponding to a location in the last page is an error
// value.
- if (ret < 0 && ret > -EXEC_PAGESIZE) {
+ if (!linux_utils::is_valid_mmap(ret)) {
libc_errno = static_cast<int>(-ret);
return MAP_FAILED;
}
generated by cgit v1.1 at 2025-10-10 04:51:14 +0000