feat(compiler-rt): update compiler-rt source files

Update the compiler-rt source files to the tip of the llvm-project [1].
To do this some new header files were pulled in from the freebsd-src
repo [2].

[1] https://github.com/llvm/llvm-project/commit/fae258e
[2] https://github.com/freebsd/freebsd-src/commit/243a0eda

Change-Id: I1a012b1fe04e127d35e208923877c98c5d999d00
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>

16 files changed, 958 insertions, 681 deletions

diff --git a/lib/compiler-rt/builtins/arm/aeabi_ldivmod.S b/lib/compiler-rt/builtins/arm/aeabi_ldivmod.S
index 038ae5d72..d0d06be6f 100644
--- a/lib/compiler-rt/builtins/arm/aeabi_ldivmod.S
+++ b/lib/compiler-rt/builtins/arm/aeabi_ldivmod.S
@@ -1,9 +1,8 @@
 //===-- aeabi_ldivmod.S - EABI ldivmod implementation ---------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/compiler-rt/builtins/arm/aeabi_uldivmod.S b/lib/compiler-rt/builtins/arm/aeabi_uldivmod.S
index be343b6bc..4fc97704d 100644
--- a/lib/compiler-rt/builtins/arm/aeabi_uldivmod.S
+++ b/lib/compiler-rt/builtins/arm/aeabi_uldivmod.S
@@ -1,9 +1,8 @@
 //===-- aeabi_uldivmod.S - EABI uldivmod implementation -------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/compiler-rt/builtins/assembly.h b/lib/compiler-rt/builtins/assembly.h
index 29d9f8844..69a3d8620 100644
--- a/lib/compiler-rt/builtins/assembly.h
+++ b/lib/compiler-rt/builtins/assembly.h
@@ -1,23 +1,27 @@
-/* ===-- assembly.h - compiler-rt assembler support macros -----------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file defines macros for use in compiler-rt assembler source.
- * This file is not part of the interface of this library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- assembly.h - compiler-rt assembler support macros -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines macros for use in compiler-rt assembler source.
+// This file is not part of the interface of this library.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef COMPILERRT_ASSEMBLY_H
 #define COMPILERRT_ASSEMBLY_H
 
-#if defined(__POWERPC__) || defined(__powerpc__) || defined(__ppc__)
-#define SEPARATOR @
+#if defined(__linux__) && defined(__CET__)
+#if __has_include(<cet.h>)
+#include <cet.h>
+#endif
+#endif
+
+#if defined(__APPLE__) && defined(__aarch64__)
+#define SEPARATOR %%
 #else
 #define SEPARATOR ;
 #endif
@@ -37,14 +41,15 @@
 #define HIDDEN(name) .hidden name
 #define LOCAL_LABEL(name) .L_##name
 #define FILE_LEVEL_DIRECTIVE
-#if defined(__arm__)
+#if defined(__arm__) || defined(__aarch64__)
 #define SYMBOL_IS_FUNC(name) .type name,%function
 #else
 #define SYMBOL_IS_FUNC(name) .type name,@function
 #endif
 #define CONST_SECTION .section .rodata
 
-#if defined(__GNU__) || defined(__ANDROID__) || defined(__FreeBSD__)
+#if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) ||        \
+    defined(__linux__)
 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
 #else
 #define NO_EXEC_STACK_DIRECTIVE
@@ -66,11 +71,103 @@
 
 #endif
 
+#if defined(__arm__) || defined(__aarch64__)
+#define FUNC_ALIGN                                                             \
+  .text SEPARATOR                                                              \
+  .balign 16 SEPARATOR
+#else
+#define FUNC_ALIGN
+#endif
+
+// BTI and PAC gnu property note
+#define NT_GNU_PROPERTY_TYPE_0 5
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI 1
+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC 2
+
+#if defined(__ARM_FEATURE_BTI_DEFAULT)
+#define BTI_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_BTI
+#else
+#define BTI_FLAG 0
+#endif
+
+#if __ARM_FEATURE_PAC_DEFAULT & 3
+#define PAC_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_PAC
+#else
+#define PAC_FLAG 0
+#endif
+
+#define GNU_PROPERTY(type, value)                                              \
+  .pushsection .note.gnu.property, "a" SEPARATOR                               \
+  .p2align 3 SEPARATOR                                                         \
+  .word 4 SEPARATOR                                                            \
+  .word 16 SEPARATOR                                                           \
+  .word NT_GNU_PROPERTY_TYPE_0 SEPARATOR                                       \
+  .asciz "GNU" SEPARATOR                                                       \
+  .word type SEPARATOR                                                         \
+  .word 4 SEPARATOR                                                            \
+  .word value SEPARATOR                                                        \
+  .word 0 SEPARATOR                                                            \
+  .popsection
+
+#if BTI_FLAG != 0
+#define BTI_C hint #34
+#define BTI_J hint #36
+#else
+#define BTI_C
+#define BTI_J
+#endif
+
+#if (BTI_FLAG | PAC_FLAG) != 0
+#define GNU_PROPERTY_BTI_PAC                                                   \
+  GNU_PROPERTY(GNU_PROPERTY_AARCH64_FEATURE_1_AND, BTI_FLAG | PAC_FLAG)
+#else
+#define GNU_PROPERTY_BTI_PAC
+#endif
+
+#if defined(__clang__) || defined(__GCC_HAVE_DWARF2_CFI_ASM)
+#define CFI_START .cfi_startproc
+#define CFI_END .cfi_endproc
+#else
+#define CFI_START
+#define CFI_END
+#endif
+
 #if defined(__arm__)
+
+// Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
+// - for '-mthumb -march=armv6' compiler defines '__thumb__'
+// - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
+#if defined(__thumb2__) || defined(__thumb__)
+#define DEFINE_CODE_STATE .thumb SEPARATOR
+#define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
+#if defined(__thumb2__)
+#define USE_THUMB_2
+#define IT(cond)  it cond
+#define ITT(cond) itt cond
+#define ITE(cond) ite cond
+#else
+#define USE_THUMB_1
+#define IT(cond)
+#define ITT(cond)
+#define ITE(cond)
+#endif // defined(__thumb__2)
+#else // !defined(__thumb2__) && !defined(__thumb__)
+#define DEFINE_CODE_STATE .arm SEPARATOR
+#define DECLARE_FUNC_ENCODING
+#define IT(cond)
+#define ITT(cond)
+#define ITE(cond)
+#endif
+
+#if defined(USE_THUMB_1) && defined(USE_THUMB_2)
+#error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
+#endif
+
 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
 #define ARM_HAS_BX
 #endif
-#if !defined(__ARM_FEATURE_CLZ) && __ARM_ARCH_ISA_THUMB != 1 &&                \
+#if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
 #define __ARM_FEATURE_CLZ
 #endif
@@ -92,40 +189,47 @@
   JMP(ip)
 #endif
 
-#if __ARM_ARCH_ISA_THUMB == 2
-#define IT(cond)  it cond
-#define ITT(cond) itt cond
-#else
-#define IT(cond)
-#define ITT(cond)
-#endif
-
-#if __ARM_ARCH_ISA_THUMB == 2
+#if defined(USE_THUMB_2)
 #define WIDE(op) op.w
 #else
 #define WIDE(op) op
 #endif
+#else // !defined(__arm)
+#define DECLARE_FUNC_ENCODING
+#define DEFINE_CODE_STATE
 #endif
 
-#define GLUE2(a, b) a##b
-#define GLUE(a, b) GLUE2(a, b)
+#define GLUE2_(a, b) a##b
+#define GLUE(a, b) GLUE2_(a, b)
+#define GLUE2(a, b) GLUE2_(a, b)
+#define GLUE3_(a, b, c) a##b##c
+#define GLUE3(a, b, c) GLUE3_(a, b, c)
+#define GLUE4_(a, b, c, d) a##b##c##d
+#define GLUE4(a, b, c, d) GLUE4_(a, b, c, d)
+
 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
 
 #ifdef VISIBILITY_HIDDEN
 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
+#define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) \
+  HIDDEN(name) SEPARATOR
 #else
 #define DECLARE_SYMBOL_VISIBILITY(name)
+#define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name)
 #endif
 
 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
   DECLARE_SYMBOL_VISIBILITY(name)                                              \
+  DECLARE_FUNC_ENCODING                                                        \
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
@@ -134,18 +238,32 @@
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
+  DECLARE_FUNC_ENCODING                                                        \
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
+  DEFINE_CODE_STATE                                                            \
   .globl name SEPARATOR                                                        \
   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
   HIDDEN(name) SEPARATOR                                                       \
+  DECLARE_FUNC_ENCODING                                                        \
   name:
 
+#define DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(name)                     \
+  DEFINE_CODE_STATE                                                            \
+  FUNC_ALIGN                                                                   \
+  .globl name SEPARATOR                                                        \
+  SYMBOL_IS_FUNC(name) SEPARATOR                                               \
+  DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) SEPARATOR                          \
+  CFI_START SEPARATOR                                                          \
+  DECLARE_FUNC_ENCODING                                                        \
+  name: SEPARATOR BTI_C
+
 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
@@ -162,8 +280,13 @@
 #ifdef __ELF__
 #define END_COMPILERRT_FUNCTION(name)                                          \
   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
+#define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
+  CFI_END SEPARATOR                                                            \
+  .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
 #else
 #define END_COMPILERRT_FUNCTION(name)
+#define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
+  CFI_END
 #endif
 
-#endif /* COMPILERRT_ASSEMBLY_H */
+#endif // COMPILERRT_ASSEMBLY_H
diff --git a/lib/compiler-rt/builtins/ctzdi2.c b/lib/compiler-rt/builtins/ctzdi2.c
index db3c6fdc0..26c908d87 100644
--- a/lib/compiler-rt/builtins/ctzdi2.c
+++ b/lib/compiler-rt/builtins/ctzdi2.c
@@ -1,29 +1,35 @@
-/* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __ctzdi2 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __ctzdi2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: the number of trailing 0-bits  */
+// Returns: the number of trailing 0-bits
 
-/* Precondition: a != 0 */
+#if !defined(__clang__) &&                                                     \
+    ((defined(__sparc__) && defined(__arch64__)) || defined(__mips64) ||       \
+     (defined(__riscv) && __SIZEOF_POINTER__ >= 8))
+// On 64-bit architectures with neither a native clz instruction nor a native
+// ctz instruction, gcc resolves __builtin_ctz to __ctzdi2 rather than
+// __ctzsi2, leading to infinite recursion.
+#define __builtin_ctz(a) __ctzsi2(a)
+extern int __ctzsi2(si_int);
+#endif
 
-COMPILER_RT_ABI si_int
-__ctzdi2(di_int a)
-{
-    dwords x;
-    x.all = a;
-    const si_int f = -(x.s.low == 0);
-    return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) +
-              (f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
+// Precondition: a != 0
+
+COMPILER_RT_ABI int __ctzdi2(di_int a) {
+  dwords x;
+  x.all = a;
+  const si_int f = -(x.s.low == 0);
+  return ctzsi((x.s.high & f) | (x.s.low & ~f)) +
+         (f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
 }
diff --git a/lib/compiler-rt/builtins/divdi3.c b/lib/compiler-rt/builtins/divdi3.c
index b8eebcb20..d71e138d9 100644
--- a/lib/compiler-rt/builtins/divdi3.c
+++ b/lib/compiler-rt/builtins/divdi3.c
@@ -1,29 +1,22 @@
-/* ===-- divdi3.c - Implement __divdi3 -------------------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __divdi3 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- divdi3.c - Implement __divdi3 -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __divdi3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: a / b */
+// Returns: a / b
 
-COMPILER_RT_ABI di_int
-__divdi3(di_int a, di_int b)
-{
-    const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
-    di_int s_a = a >> bits_in_dword_m1;           /* s_a = a < 0 ? -1 : 0 */
-    di_int s_b = b >> bits_in_dword_m1;           /* s_b = b < 0 ? -1 : 0 */
-    a = (a ^ s_a) - s_a;                         /* negate if s_a == -1 */
-    b = (b ^ s_b) - s_b;                         /* negate if s_b == -1 */
-    s_a ^= s_b;                                  /*sign of quotient */
-    return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a;  /* negate if s_a == -1 */
-}
+#define fixint_t di_int
+#define fixuint_t du_int
+#define COMPUTE_UDIV(a, b) __udivmoddi4((a), (b), (du_int *)0)
+#include "int_div_impl.inc"
+
+COMPILER_RT_ABI di_int __divdi3(di_int a, di_int b) { return __divXi3(a, b); }
diff --git a/lib/compiler-rt/builtins/divmoddi4.c b/lib/compiler-rt/builtins/divmoddi4.c
index 0d4df67a6..e7cbbb1aa 100644
--- a/lib/compiler-rt/builtins/divmoddi4.c
+++ b/lib/compiler-rt/builtins/divmoddi4.c
@@ -1,25 +1,28 @@
-/*===-- divmoddi4.c - Implement __divmoddi4 --------------------------------===
- *
- *                    The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __divmoddi4 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- divmoddi4.c - Implement __divmoddi4 -------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __divmoddi4 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: a / b, *rem = a % b  */
+// Returns: a / b, *rem = a % b
 
-COMPILER_RT_ABI di_int
-__divmoddi4(di_int a, di_int b, di_int* rem)
-{
-  di_int d = __divdi3(a,b);
-  *rem = a - (d*b);
-  return d;
+COMPILER_RT_ABI di_int __divmoddi4(di_int a, di_int b, di_int *rem) {
+  const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
+  di_int s_a = a >> bits_in_dword_m1;                   // s_a = a < 0 ? -1 : 0
+  di_int s_b = b >> bits_in_dword_m1;                   // s_b = b < 0 ? -1 : 0
+  a = (a ^ s_a) - s_a;                                  // negate if s_a == -1
+  b = (b ^ s_b) - s_b;                                  // negate if s_b == -1
+  s_b ^= s_a;                                           // sign of quotient
+  du_int r;
+  di_int q = (__udivmoddi4(a, b, &r) ^ s_b) - s_b;      // negate if s_b == -1
+  *rem = (r ^ s_a) - s_a;                               // negate if s_a == -1
+  return q;
 }
diff --git a/lib/compiler-rt/builtins/int_div_impl.inc b/lib/compiler-rt/builtins/int_div_impl.inc
new file mode 100644
index 000000000..dc1f97cbe
--- /dev/null
+++ b/lib/compiler-rt/builtins/int_div_impl.inc
@@ -0,0 +1,95 @@
+//===-- int_div_impl.inc - Integer division ---------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Helpers used by __udivsi3, __umodsi3, __udivdi3, and __umodsi3.
+//
+//===----------------------------------------------------------------------===//
+
+#define clz(a) (sizeof(a) == sizeof(unsigned long long) ? __builtin_clzll(a) : clzsi(a))
+
+// Adapted from Figure 3-40 of The PowerPC Compiler Writer's Guide
+static __inline fixuint_t __udivXi3(fixuint_t n, fixuint_t d) {
+  const unsigned N = sizeof(fixuint_t) * CHAR_BIT;
+  // d == 0 cases are unspecified.
+  unsigned sr = (d ? clz(d) : N) - (n ? clz(n) : N);
+  // 0 <= sr <= N - 1 or sr is very large.
+  if (sr > N - 1) // n < d
+    return 0;
+  if (sr == N - 1) // d == 1
+    return n;
+  ++sr;
+  // 1 <= sr <= N - 1. Shifts do not trigger UB.
+  fixuint_t r = n >> sr;
+  n <<= N - sr;
+  fixuint_t carry = 0;
+  for (; sr > 0; --sr) {
+    r = (r << 1) | (n >> (N - 1));
+    n = (n << 1) | carry;
+    // Branch-less version of:
+    // carry = 0;
+    // if (r >= d) r -= d, carry = 1;
+    const fixint_t s = (fixint_t)(d - r - 1) >> (N - 1);
+    carry = s & 1;
+    r -= d & s;
+  }
+  n = (n << 1) | carry;
+  return n;
+}
+
+// Mostly identical to __udivXi3 but the return values are different.
+static __inline fixuint_t __umodXi3(fixuint_t n, fixuint_t d) {
+  const unsigned N = sizeof(fixuint_t) * CHAR_BIT;
+  // d == 0 cases are unspecified.
+  unsigned sr = (d ? clz(d) : N) - (n ? clz(n) : N);
+  // 0 <= sr <= N - 1 or sr is very large.
+  if (sr > N - 1) // n < d
+    return n;
+  if (sr == N - 1) // d == 1
+    return 0;
+  ++sr;
+  // 1 <= sr <= N - 1. Shifts do not trigger UB.
+  fixuint_t r = n >> sr;
+  n <<= N - sr;
+  fixuint_t carry = 0;
+  for (; sr > 0; --sr) {
+    r = (r << 1) | (n >> (N - 1));
+    n = (n << 1) | carry;
+    // Branch-less version of:
+    // carry = 0;
+    // if (r >= d) r -= d, carry = 1;
+    const fixint_t s = (fixint_t)(d - r - 1) >> (N - 1);
+    carry = s & 1;
+    r -= d & s;
+  }
+  return r;
+}
+
+#ifdef COMPUTE_UDIV
+static __inline fixint_t __divXi3(fixint_t a, fixint_t b) {
+  const int N = (int)(sizeof(fixint_t) * CHAR_BIT) - 1;
+  fixint_t s_a = a >> N;                            // s_a = a < 0 ? -1 : 0
+  fixint_t s_b = b >> N;                            // s_b = b < 0 ? -1 : 0
+  fixuint_t a_u = (fixuint_t)(a ^ s_a) + (-s_a);    // negate if s_a == -1
+  fixuint_t b_u = (fixuint_t)(b ^ s_b) + (-s_b);    // negate if s_b == -1
+  s_a ^= s_b;                                       // sign of quotient
+  return (COMPUTE_UDIV(a_u, b_u) ^ s_a) + (-s_a);   // negate if s_a == -1
+}
+#endif // COMPUTE_UDIV
+
+#ifdef ASSIGN_UMOD
+static __inline fixint_t __modXi3(fixint_t a, fixint_t b) {
+  const int N = (int)(sizeof(fixint_t) * CHAR_BIT) - 1;
+  fixint_t s = b >> N;                              // s = b < 0 ? -1 : 0
+  fixuint_t b_u = (fixuint_t)(b ^ s) + (-s);        // negate if s == -1
+  s = a >> N;                                       // s = a < 0 ? -1 : 0
+  fixuint_t a_u = (fixuint_t)(a ^ s) + (-s);        // negate if s == -1
+  fixuint_t res;
+  ASSIGN_UMOD(res, a_u, b_u);
+  return (res ^ s) + (-s);                          // negate if s == -1
+}
+#endif // ASSIGN_UMOD
diff --git a/lib/compiler-rt/builtins/int_endianness.h b/lib/compiler-rt/builtins/int_endianness.h
index 7995ddbb9..291c6b58c 100644
--- a/lib/compiler-rt/builtins/int_endianness.h
+++ b/lib/compiler-rt/builtins/int_endianness.h
@@ -1,51 +1,49 @@
-/* ===-- int_endianness.h - configuration header for compiler-rt ------------===
- *
- *		       The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file is a configuration header for compiler-rt.
- * This file is not part of the interface of this library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- int_endianness.h - configuration header for compiler-rt -----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a configuration header for compiler-rt.
+// This file is not part of the interface of this library.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef INT_ENDIANNESS_H
 #define INT_ENDIANNESS_H
 
-#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
+#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) &&                \
     defined(__ORDER_LITTLE_ENDIAN__)
 
-/* Clang and GCC provide built-in endianness definitions. */
+// Clang and GCC provide built-in endianness definitions.
 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #define _YUGA_LITTLE_ENDIAN 0
-#define _YUGA_BIG_ENDIAN    1
+#define _YUGA_BIG_ENDIAN 1
 #elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
-#endif /* __BYTE_ORDER__ */
+#define _YUGA_BIG_ENDIAN 0
+#endif // __BYTE_ORDER__
 
-#else /* Compilers other than Clang or GCC. */
+#else // Compilers other than Clang or GCC.
 
 #if defined(__SVR4) && defined(__sun)
 #include <sys/byteorder.h>
 
 #if defined(_BIG_ENDIAN)
 #define _YUGA_LITTLE_ENDIAN 0
-#define _YUGA_BIG_ENDIAN    1
+#define _YUGA_BIG_ENDIAN 1
 #elif defined(_LITTLE_ENDIAN)
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
-#else /* !_LITTLE_ENDIAN */
+#define _YUGA_BIG_ENDIAN 0
+#else // !_LITTLE_ENDIAN
 #error "unknown endianness"
-#endif /* !_LITTLE_ENDIAN */
+#endif // !_LITTLE_ENDIAN
 
-#endif /* Solaris and AuroraUX. */
+#endif // Solaris
 
-/* .. */
+// ..
 
 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__) ||   \
     defined(__minix)
@@ -53,64 +51,64 @@
 
 #if _BYTE_ORDER == _BIG_ENDIAN
 #define _YUGA_LITTLE_ENDIAN 0
-#define _YUGA_BIG_ENDIAN    1
+#define _YUGA_BIG_ENDIAN 1
 #elif _BYTE_ORDER == _LITTLE_ENDIAN
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
-#endif /* _BYTE_ORDER */
+#define _YUGA_BIG_ENDIAN 0
+#endif // _BYTE_ORDER
 
-#endif /* *BSD */
+#endif // *BSD
 
-#if defined(__OpenBSD__) || defined(__Bitrig__)
+#if defined(__OpenBSD__)
 #include <machine/endian.h>
 
 #if _BYTE_ORDER == _BIG_ENDIAN
 #define _YUGA_LITTLE_ENDIAN 0
-#define _YUGA_BIG_ENDIAN    1
+#define _YUGA_BIG_ENDIAN 1
 #elif _BYTE_ORDER == _LITTLE_ENDIAN
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
-#endif /* _BYTE_ORDER */
+#define _YUGA_BIG_ENDIAN 0
+#endif // _BYTE_ORDER
 
-#endif /* OpenBSD and Bitrig. */
+#endif // OpenBSD
 
-/* .. */
+// ..
 
-/* Mac OSX has __BIG_ENDIAN__ or __LITTLE_ENDIAN__ automatically set by the
- * compiler (at least with GCC) */
-#if defined(__APPLE__) || defined(__ellcc__ )
+// Mac OSX has __BIG_ENDIAN__ or __LITTLE_ENDIAN__ automatically set by the
+// compiler (at least with GCC)
+#if defined(__APPLE__) || defined(__ellcc__)
 
 #ifdef __BIG_ENDIAN__
 #if __BIG_ENDIAN__
 #define _YUGA_LITTLE_ENDIAN 0
-#define _YUGA_BIG_ENDIAN    1
+#define _YUGA_BIG_ENDIAN 1
 #endif
-#endif /* __BIG_ENDIAN__ */
+#endif // __BIG_ENDIAN__
 
 #ifdef __LITTLE_ENDIAN__
 #if __LITTLE_ENDIAN__
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
+#define _YUGA_BIG_ENDIAN 0
 #endif
-#endif /* __LITTLE_ENDIAN__ */
+#endif // __LITTLE_ENDIAN__
 
-#endif /* Mac OSX */
+#endif // Mac OSX
 
-/* .. */
+// ..
 
 #if defined(_WIN32)
 
 #define _YUGA_LITTLE_ENDIAN 1
-#define _YUGA_BIG_ENDIAN    0
+#define _YUGA_BIG_ENDIAN 0
 
-#endif /* Windows */
+#endif // Windows
 
-#endif /* Clang or GCC. */
+#endif // Clang or GCC.
 
-/* . */
+// .
 
 #if !defined(_YUGA_LITTLE_ENDIAN) || !defined(_YUGA_BIG_ENDIAN)
 #error Unable to determine endian
-#endif /* Check we found an endianness correctly. */
+#endif // Check we found an endianness correctly.
 
-#endif /* INT_ENDIANNESS_H */
+#endif // INT_ENDIANNESS_H
diff --git a/lib/compiler-rt/builtins/int_lib.h b/lib/compiler-rt/builtins/int_lib.h
index 80a7c41a4..fb791ebc4 100644
--- a/lib/compiler-rt/builtins/int_lib.h
+++ b/lib/compiler-rt/builtins/int_lib.h
@@ -1,49 +1,33 @@
-/* ===-- int_lib.h - configuration header for compiler-rt  -----------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file is a configuration header for compiler-rt.
- * This file is not part of the interface of this library.
- *
- * ===----------------------------------------------------------------------===
- */
-
-/*
- * Portions copyright (c) 2017-2018, ARM Limited and Contributors.
- * All rights reserved.
- */
+//===-- int_lib.h - configuration header for compiler-rt  -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a configuration header for compiler-rt.
+// This file is not part of the interface of this library.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef INT_LIB_H
 #define INT_LIB_H
 
-/* Assumption: Signed integral is 2's complement. */
-/* Assumption: Right shift of signed negative is arithmetic shift. */
-/* Assumption: Endianness is little or big (not mixed). */
+// Assumption: Signed integral is 2's complement.
+// Assumption: Right shift of signed negative is arithmetic shift.
+// Assumption: Endianness is little or big (not mixed).
 
-#if defined(__ELF__)
-#define FNALIAS(alias_name, original_name) \
-  void alias_name() __attribute__((__alias__(#original_name)))
-#define COMPILER_RT_ALIAS(aliasee) __attribute__((__alias__(#aliasee)))
-#else
-#define FNALIAS(alias, name) _Pragma("GCC error(\"alias unsupported on this file format\")")
-#define COMPILER_RT_ALIAS(aliasee) _Pragma("GCC error(\"alias unsupported on this file format\")")
-#endif
-
-/* ABI macro definitions */
+// ABI macro definitions
 
 #if __ARM_EABI__
-# ifdef COMPILER_RT_ARMHF_TARGET
-#   define COMPILER_RT_ABI
-# else
-#   define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
-# endif
+#ifdef COMPILER_RT_ARMHF_TARGET
+#define COMPILER_RT_ABI
+#else
+#define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
+#endif
 #else
-# define COMPILER_RT_ABI
+#define COMPILER_RT_ABI
 #endif
 
 #define AEABI_RTABI __attribute__((__pcs__("aapcs")))
@@ -60,42 +44,89 @@
 #define UNUSED __attribute__((unused))
 #endif
 
-/*
- * Kernel and boot environment can't use normal headers,
- * so use the equivalent system headers.
- */
-#  include <limits.h>
-#  include <stdint.h>
+#define STR(a) #a
+#define XSTR(a) STR(a)
+#define SYMBOL_NAME(name) XSTR(__USER_LABEL_PREFIX__) #name
+
+#if defined(__ELF__) || defined(__MINGW32__) || defined(__wasm__) ||           \
+    defined(_AIX)
+#define COMPILER_RT_ALIAS(name, aliasname) \
+  COMPILER_RT_ABI __typeof(name) aliasname __attribute__((__alias__(#name)));
+#elif defined(__APPLE__)
+#if defined(VISIBILITY_HIDDEN)
+#define COMPILER_RT_ALIAS_VISIBILITY(name) \
+  __asm__(".private_extern " SYMBOL_NAME(name));
+#else
+#define COMPILER_RT_ALIAS_VISIBILITY(name)
+#endif
+#define COMPILER_RT_ALIAS(name, aliasname) \
+  __asm__(".globl " SYMBOL_NAME(aliasname)); \
+  COMPILER_RT_ALIAS_VISIBILITY(aliasname) \
+  __asm__(SYMBOL_NAME(aliasname) " = " SYMBOL_NAME(name)); \
+  COMPILER_RT_ABI __typeof(name) aliasname;
+#elif defined(_WIN32)
+#define COMPILER_RT_ALIAS(name, aliasname)
+#else
+#error Unsupported target
+#endif
+
+#if (defined(__FreeBSD__) || defined(__NetBSD__)) &&                           \
+    (defined(_KERNEL) || defined(_STANDALONE))
+//
+// Kernel and boot environment can't use normal headers,
+// so use the equivalent system headers.
+// NB: FreeBSD (and OpenBSD) deprecate machine/limits.h in
+// favour of sys/limits.h, so prefer the former, but fall
+// back on the latter if not available since NetBSD only has
+// the latter.
+//
+#if defined(__has_include) && __has_include(<sys/limits.h>)
+#include <sys/limits.h>
+#else
+#include <machine/limits.h>
+#endif
+#include <sys/stdint.h>
+#include <sys/types.h>
+#else
+// Include the standard compiler builtin headers we use functionality from.
+#include <float.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#endif
 
-/* Include the commonly used internal type definitions. */
+// Include the commonly used internal type definitions.
 #include "int_types.h"
 
-COMPILER_RT_ABI si_int __paritysi2(si_int a);
-COMPILER_RT_ABI si_int __paritydi2(di_int a);
+// Include internal utility function declarations.
+#include "int_util.h"
+
+COMPILER_RT_ABI int __paritysi2(si_int a);
+COMPILER_RT_ABI int __paritydi2(di_int a);
 
 COMPILER_RT_ABI di_int __divdi3(di_int a, di_int b);
 COMPILER_RT_ABI si_int __divsi3(si_int a, si_int b);
 COMPILER_RT_ABI su_int __udivsi3(su_int n, su_int d);
 
-COMPILER_RT_ABI su_int __udivmodsi4(su_int a, su_int b, su_int* rem);
-COMPILER_RT_ABI du_int __udivmoddi4(du_int a, du_int b, du_int* rem);
+COMPILER_RT_ABI su_int __udivmodsi4(su_int a, su_int b, su_int *rem);
+COMPILER_RT_ABI du_int __udivmoddi4(du_int a, du_int b, du_int *rem);
 #ifdef CRT_HAS_128BIT
-COMPILER_RT_ABI si_int __clzti2(ti_int a);
-COMPILER_RT_ABI tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);
+COMPILER_RT_ABI int __clzti2(ti_int a);
+COMPILER_RT_ABI tu_int __udivmodti4(tu_int a, tu_int b, tu_int *rem);
 #endif
 
-/* Definitions for builtins unavailable on MSVC */
+// Definitions for builtins unavailable on MSVC
 #if defined(_MSC_VER) && !defined(__clang__)
 #include <intrin.h>
 
-uint32_t __inline __builtin_ctz(uint32_t value) {
+int __inline __builtin_ctz(uint32_t value) {
   unsigned long trailing_zero = 0;
   if (_BitScanForward(&trailing_zero, value))
     return trailing_zero;
   return 32;
 }
 
-uint32_t __inline __builtin_clz(uint32_t value) {
+int __inline __builtin_clz(uint32_t value) {
   unsigned long leading_zero = 0;
   if (_BitScanReverse(&leading_zero, value))
     return 31 - leading_zero;
@@ -103,14 +134,14 @@ uint32_t __inline __builtin_clz(uint32_t value) {
 }
 
 #if defined(_M_ARM) || defined(_M_X64)
-uint32_t __inline __builtin_clzll(uint64_t value) {
+int __inline __builtin_clzll(uint64_t value) {
   unsigned long leading_zero = 0;
   if (_BitScanReverse64(&leading_zero, value))
     return 63 - leading_zero;
   return 64;
 }
 #else
-uint32_t __inline __builtin_clzll(uint64_t value) {
+int __inline __builtin_clzll(uint64_t value) {
   if (value == 0)
     return 64;
   uint32_t msh = (uint32_t)(value >> 32);
@@ -122,6 +153,19 @@ uint32_t __inline __builtin_clzll(uint64_t value) {
 #endif
 
 #define __builtin_clzl __builtin_clzll
-#endif /* defined(_MSC_VER) && !defined(__clang__) */
 
-#endif /* INT_LIB_H */
+bool __inline __builtin_sadd_overflow(int x, int y, int *result) {
+  if ((x < 0) != (y < 0)) {
+    *result = x + y;
+    return false;
+  }
+  int tmp = (unsigned int)x + (unsigned int)y;
+  if ((tmp < 0) != (x < 0))
+    return true;
+  *result = tmp;
+  return false;
+}
+
+#endif // defined(_MSC_VER) && !defined(__clang__)
+
+#endif // INT_LIB_H
diff --git a/lib/compiler-rt/builtins/int_math.h b/lib/compiler-rt/builtins/int_math.h
index fc81fb7f0..48b9580f5 100644
--- a/lib/compiler-rt/builtins/int_math.h
+++ b/lib/compiler-rt/builtins/int_math.h
@@ -1,34 +1,31 @@
-/* ===-- int_math.h - internal math inlines ---------------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===-----------------------------------------------------------------------===
- *
- * This file is not part of the interface of this library.
- *
- * This file defines substitutes for the libm functions used in some of the
- * compiler-rt implementations, defined in such a way that there is not a direct
- * dependency on libm or math.h. Instead, we use the compiler builtin versions
- * where available. This reduces our dependencies on the system SDK by foisting
- * the responsibility onto the compiler.
- *
- * ===-----------------------------------------------------------------------===
- */
+//===-- int_math.h - internal math inlines --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is not part of the interface of this library.
+//
+// This file defines substitutes for the libm functions used in some of the
+// compiler-rt implementations, defined in such a way that there is not a direct
+// dependency on libm or math.h. Instead, we use the compiler builtin versions
+// where available. This reduces our dependencies on the system SDK by foisting
+// the responsibility onto the compiler.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef INT_MATH_H
 #define INT_MATH_H
 
 #ifndef __has_builtin
-#  define  __has_builtin(x) 0
+#define __has_builtin(x) 0
 #endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
 #include <math.h>
 #include <stdlib.h>
-#include <ymath.h>
 #endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
@@ -42,24 +39,23 @@
 #define crt_isinf(x) !_finite((x))
 #define crt_isnan(x) _isnan((x))
 #else
-/* Define crt_isfinite in terms of the builtin if available, otherwise provide
- * an alternate version in terms of our other functions. This supports some
- * versions of GCC which didn't have __builtin_isfinite.
- */
+// Define crt_isfinite in terms of the builtin if available, otherwise provide
+// an alternate version in terms of our other functions. This supports some
+// versions of GCC which didn't have __builtin_isfinite.
 #if __has_builtin(__builtin_isfinite)
-#  define crt_isfinite(x) __builtin_isfinite((x))
+#define crt_isfinite(x) __builtin_isfinite((x))
 #elif defined(__GNUC__)
-#  define crt_isfinite(x) \
-  __extension__(({ \
-      __typeof((x)) x_ = (x); \
-      !crt_isinf(x_) && !crt_isnan(x_); \
-    }))
+#define crt_isfinite(x)                                                        \
+  __extension__(({                                                             \
+    __typeof((x)) x_ = (x);                                                    \
+    !crt_isinf(x_) && !crt_isnan(x_);                                          \
+  }))
 #else
-#  error "Do not know how to check for infinity"
-#endif /* __has_builtin(__builtin_isfinite) */
+#error "Do not know how to check for infinity"
+#endif // __has_builtin(__builtin_isfinite)
 #define crt_isinf(x) __builtin_isinf((x))
 #define crt_isnan(x) __builtin_isnan((x))
-#endif /* _MSC_VER */
+#endif // _MSC_VER
 
 #if defined(_MSC_VER) && !defined(__clang__)
 #define crt_copysign(x, y) copysign((x), (y))
@@ -82,33 +78,21 @@
 #endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
-#define crt_fmax(x, y) __max((x), (y))
-#define crt_fmaxf(x, y) __max((x), (y))
 #define crt_fmaxl(x, y) __max((x), (y))
 #else
-#define crt_fmax(x, y) __builtin_fmax((x), (y))
-#define crt_fmaxf(x, y) __builtin_fmaxf((x), (y))
 #define crt_fmaxl(x, y) __builtin_fmaxl((x), (y))
 #endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
-#define crt_logb(x) logb((x))
-#define crt_logbf(x) logbf((x))
 #define crt_logbl(x) logbl((x))
 #else
-#define crt_logb(x) __builtin_logb((x))
-#define crt_logbf(x) __builtin_logbf((x))
 #define crt_logbl(x) __builtin_logbl((x))
 #endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
-#define crt_scalbn(x, y) scalbn((x), (y))
-#define crt_scalbnf(x, y) scalbnf((x), (y))
 #define crt_scalbnl(x, y) scalbnl((x), (y))
 #else
-#define crt_scalbn(x, y) __builtin_scalbn((x), (y))
-#define crt_scalbnf(x, y) __builtin_scalbnf((x), (y))
 #define crt_scalbnl(x, y) __builtin_scalbnl((x), (y))
 #endif
 
-#endif /* INT_MATH_H */
+#endif // INT_MATH_H
diff --git a/lib/compiler-rt/builtins/int_types.h b/lib/compiler-rt/builtins/int_types.h
index 660385ecd..7a72de480 100644
--- a/lib/compiler-rt/builtins/int_types.h
+++ b/lib/compiler-rt/builtins/int_types.h
@@ -1,148 +1,174 @@
-/* ===-- int_lib.h - configuration header for compiler-rt  -----------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file is not part of the interface of this library.
- *
- * This file defines various standard types, most importantly a number of unions
- * used to access parts of larger types.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- int_lib.h - configuration header for compiler-rt  -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is not part of the interface of this library.
+//
+// This file defines various standard types, most importantly a number of unions
+// used to access parts of larger types.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef INT_TYPES_H
 #define INT_TYPES_H
 
 #include "int_endianness.h"
 
-/* si_int is defined in Linux sysroot's asm-generic/siginfo.h */
+// si_int is defined in Linux sysroot's asm-generic/siginfo.h
 #ifdef si_int
 #undef si_int
 #endif
-typedef      int si_int;
-typedef unsigned su_int;
+typedef int32_t si_int;
+typedef uint32_t su_int;
+#if UINT_MAX == 0xFFFFFFFF
+#define clzsi __builtin_clz
+#define ctzsi __builtin_ctz
+#elif ULONG_MAX == 0xFFFFFFFF
+#define clzsi __builtin_clzl
+#define ctzsi __builtin_ctzl
+#else
+#error could not determine appropriate clzsi macro for this system
+#endif
 
-typedef          long long di_int;
-typedef unsigned long long du_int;
+typedef int64_t di_int;
+typedef uint64_t du_int;
 
-typedef union
-{
-    di_int all;
-    struct
-    {
+typedef union {
+  di_int all;
+  struct {
 #if _YUGA_LITTLE_ENDIAN
-        su_int low;
-        si_int high;
+    su_int low;
+    si_int high;
 #else
-        si_int high;
-        su_int low;
-#endif /* _YUGA_LITTLE_ENDIAN */
-    }s;
+    si_int high;
+    su_int low;
+#endif // _YUGA_LITTLE_ENDIAN
+  } s;
 } dwords;
 
-typedef union
-{
-    du_int all;
-    struct
-    {
+typedef union {
+  du_int all;
+  struct {
 #if _YUGA_LITTLE_ENDIAN
-        su_int low;
-        su_int high;
+    su_int low;
+    su_int high;
 #else
-        su_int high;
-        su_int low;
-#endif /* _YUGA_LITTLE_ENDIAN */
-    }s;
+    su_int high;
+    su_int low;
+#endif // _YUGA_LITTLE_ENDIAN
+  } s;
 } udwords;
 
-/* MIPS64 issue: PR 20098 */
-#if (defined(__LP64__) || defined(__wasm__)) && \
-    !(defined(__mips__) && defined(__clang__))
+#if defined(__LP64__) || defined(__wasm__) || defined(__mips64) ||             \
+    defined(__riscv) || defined(_WIN64)
 #define CRT_HAS_128BIT
 #endif
 
+// MSVC doesn't have a working 128bit integer type. Users should really compile
+// compiler-rt with clang, but if they happen to be doing a standalone build for
+// asan or something else, disable the 128 bit parts so things sort of work.
+#if defined(_MSC_VER) && !defined(__clang__)
+#undef CRT_HAS_128BIT
+#endif
+
 #ifdef CRT_HAS_128BIT
-typedef int      ti_int __attribute__ ((mode (TI)));
-typedef unsigned tu_int __attribute__ ((mode (TI)));
-
-typedef union
-{
-    ti_int all;
-    struct
-    {
+typedef int ti_int __attribute__((mode(TI)));
+typedef unsigned tu_int __attribute__((mode(TI)));
+
+typedef union {
+  ti_int all;
+  struct {
 #if _YUGA_LITTLE_ENDIAN
-        du_int low;
-        di_int high;
+    du_int low;
+    di_int high;
 #else
-        di_int high;
-        du_int low;
-#endif /* _YUGA_LITTLE_ENDIAN */
-    }s;
+    di_int high;
+    du_int low;
+#endif // _YUGA_LITTLE_ENDIAN
+  } s;
 } twords;
 
-typedef union
-{
-    tu_int all;
-    struct
-    {
+typedef union {
+  tu_int all;
+  struct {
 #if _YUGA_LITTLE_ENDIAN
-        du_int low;
-        du_int high;
+    du_int low;
+    du_int high;
 #else
-        du_int high;
-        du_int low;
-#endif /* _YUGA_LITTLE_ENDIAN */
-    }s;
+    du_int high;
+    du_int low;
+#endif // _YUGA_LITTLE_ENDIAN
+  } s;
 } utwords;
 
 static __inline ti_int make_ti(di_int h, di_int l) {
-    twords r;
-    r.s.high = h;
-    r.s.low = l;
-    return r.all;
+  twords r;
+  r.s.high = h;
+  r.s.low = l;
+  return r.all;
 }
 
 static __inline tu_int make_tu(du_int h, du_int l) {
-    utwords r;
-    r.s.high = h;
-    r.s.low = l;
-    return r.all;
+  utwords r;
+  r.s.high = h;
+  r.s.low = l;
+  return r.all;
 }
 
-#endif /* CRT_HAS_128BIT */
+#endif // CRT_HAS_128BIT
+
+// FreeBSD's boot environment does not support using floating-point and poisons
+// the float and double keywords.
+#if defined(__FreeBSD__) && defined(_STANDALONE)
+#define CRT_HAS_FLOATING_POINT 0
+#else
+#define CRT_HAS_FLOATING_POINT 1
+#endif
 
-typedef union
-{
-    su_int u;
-    float f;
+#if CRT_HAS_FLOATING_POINT
+typedef union {
+  su_int u;
+  float f;
 } float_bits;
 
-typedef union
-{
-    udwords u;
-    double  f;
+typedef union {
+  udwords u;
+  double f;
 } double_bits;
+#endif
 
-typedef struct
-{
+typedef struct {
 #if _YUGA_LITTLE_ENDIAN
-    udwords low;
-    udwords high;
+  udwords low;
+  udwords high;
 #else
-    udwords high;
-    udwords low;
-#endif /* _YUGA_LITTLE_ENDIAN */
+  udwords high;
+  udwords low;
+#endif // _YUGA_LITTLE_ENDIAN
 } uqwords;
 
-typedef union
-{
-    uqwords     u;
-    long double f;
+// Check if the target supports 80 bit extended precision long doubles.
+// Notably, on x86 Windows, MSVC only provides a 64-bit long double, but GCC
+// still makes it 80 bits. Clang will match whatever compiler it is trying to
+// be compatible with. On 32-bit x86 Android, long double is 64 bits, while on
+// x86_64 Android, long double is 128 bits.
+#if (defined(__i386__) || defined(__x86_64__)) &&                              \
+    !(defined(_MSC_VER) || defined(__ANDROID__))
+#define HAS_80_BIT_LONG_DOUBLE 1
+#elif defined(__m68k__) || defined(__ia64__)
+#define HAS_80_BIT_LONG_DOUBLE 1
+#else
+#define HAS_80_BIT_LONG_DOUBLE 0
+#endif
+
+#if CRT_HAS_FLOATING_POINT
+typedef union {
+  uqwords u;
+  long double f;
 } long_double_bits;
 
 #if __STDC_VERSION__ >= 199901L
@@ -153,14 +179,20 @@ typedef long double _Complex Lcomplex;
 #define COMPLEX_REAL(x) __real__(x)
 #define COMPLEX_IMAGINARY(x) __imag__(x)
 #else
-typedef struct { float real, imaginary; } Fcomplex;
+typedef struct {
+  float real, imaginary;
+} Fcomplex;
 
-typedef struct { double real, imaginary; } Dcomplex;
+typedef struct {
+  double real, imaginary;
+} Dcomplex;
 
-typedef struct { long double real, imaginary; } Lcomplex;
+typedef struct {
+  long double real, imaginary;
+} Lcomplex;
 
 #define COMPLEX_REAL(x) (x).real
 #define COMPLEX_IMAGINARY(x) (x).imaginary
 #endif
-#endif /* INT_TYPES_H */
-
+#endif
+#endif // INT_TYPES_H
diff --git a/lib/compiler-rt/builtins/int_util.h b/lib/compiler-rt/builtins/int_util.h
new file mode 100644
index 000000000..c372c2edc
--- /dev/null
+++ b/lib/compiler-rt/builtins/int_util.h
@@ -0,0 +1,47 @@
+//===-- int_util.h - internal utility functions ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is not part of the interface of this library.
+//
+// This file defines non-inline utilities which are available for use in the
+// library. The function definitions themselves are all contained in int_util.c
+// which will always be compiled into any compiler-rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef INT_UTIL_H
+#define INT_UTIL_H
+
+/// \brief Trigger a program abort (or panic for kernel code).
+#define compilerrt_abort() __compilerrt_abort_impl(__FILE__, __LINE__, __func__)
+
+NORETURN void __compilerrt_abort_impl(const char *file, int line,
+                                      const char *function);
+
+#define COMPILE_TIME_ASSERT(expr) COMPILE_TIME_ASSERT1(expr, __COUNTER__)
+#define COMPILE_TIME_ASSERT1(expr, cnt) COMPILE_TIME_ASSERT2(expr, cnt)
+#define COMPILE_TIME_ASSERT2(expr, cnt)                                        \
+  typedef char ct_assert_##cnt[(expr) ? 1 : -1] UNUSED
+
+// Force unrolling the code specified to be repeated N times.
+#define REPEAT_0_TIMES(code_to_repeat) /* do nothing */
+#define REPEAT_1_TIMES(code_to_repeat) code_to_repeat
+#define REPEAT_2_TIMES(code_to_repeat)                                         \
+  REPEAT_1_TIMES(code_to_repeat)                                               \
+  code_to_repeat
+#define REPEAT_3_TIMES(code_to_repeat)                                         \
+  REPEAT_2_TIMES(code_to_repeat)                                               \
+  code_to_repeat
+#define REPEAT_4_TIMES(code_to_repeat)                                         \
+  REPEAT_3_TIMES(code_to_repeat)                                               \
+  code_to_repeat
+
+#define REPEAT_N_TIMES_(N, code_to_repeat) REPEAT_##N##_TIMES(code_to_repeat)
+#define REPEAT_N_TIMES(N, code_to_repeat) REPEAT_N_TIMES_(N, code_to_repeat)
+
+#endif // INT_UTIL_H
diff --git a/lib/compiler-rt/builtins/lshrdi3.c b/lib/compiler-rt/builtins/lshrdi3.c
index 67b2a7668..607215258 100644
--- a/lib/compiler-rt/builtins/lshrdi3.c
+++ b/lib/compiler-rt/builtins/lshrdi3.c
@@ -1,45 +1,38 @@
-/* ===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __lshrdi3 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __lshrdi3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: logical a >> b */
+// Returns: logical a >> b
 
-/* Precondition:  0 <= b < bits_in_dword */
+// Precondition:  0 <= b < bits_in_dword
 
-COMPILER_RT_ABI di_int
-__lshrdi3(di_int a, si_int b)
-{
-    const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
-    udwords input;
-    udwords result;
-    input.all = a;
-    if (b & bits_in_word)  /* bits_in_word <= b < bits_in_dword */
-    {
-        result.s.high = 0;
-        result.s.low = input.s.high >> (b - bits_in_word);
-    }
-    else  /* 0 <= b < bits_in_word */
-    {
-        if (b == 0)
-            return a;
-        result.s.high  = input.s.high >> b;
-        result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
-    }
-    return result.all;
+COMPILER_RT_ABI di_int __lshrdi3(di_int a, int b) {
+  const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
+  udwords input;
+  udwords result;
+  input.all = a;
+  if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ {
+    result.s.high = 0;
+    result.s.low = input.s.high >> (b - bits_in_word);
+  } else /* 0 <= b < bits_in_word */ {
+    if (b == 0)
+      return a;
+    result.s.high = input.s.high >> b;
+    result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
+  }
+  return result.all;
 }
 
 #if defined(__ARM_EABI__)
-AEABI_RTABI di_int __aeabi_llsr(di_int a, si_int b) COMPILER_RT_ALIAS(__lshrdi3);
+COMPILER_RT_ALIAS(__lshrdi3, __aeabi_llsr)
 #endif
diff --git a/lib/compiler-rt/builtins/popcountdi2.c b/lib/compiler-rt/builtins/popcountdi2.c
index 5e8a62f07..20dd0b023 100644
--- a/lib/compiler-rt/builtins/popcountdi2.c
+++ b/lib/compiler-rt/builtins/popcountdi2.c
@@ -1,36 +1,32 @@
-/* ===-- popcountdi2.c - Implement __popcountdi2 ----------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __popcountdi2 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- popcountdi2.c - Implement __popcountdi2 ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __popcountdi2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: count of 1 bits */
+// Returns: count of 1 bits
 
-COMPILER_RT_ABI si_int
-__popcountdi2(di_int a)
-{
-    du_int x2 = (du_int)a;
-    x2 = x2 - ((x2 >> 1) & 0x5555555555555555uLL);
-    /* Every 2 bits holds the sum of every pair of bits (32) */
-    x2 = ((x2 >> 2) & 0x3333333333333333uLL) + (x2 & 0x3333333333333333uLL);
-    /* Every 4 bits holds the sum of every 4-set of bits (3 significant bits) (16) */
-    x2 = (x2 + (x2 >> 4)) & 0x0F0F0F0F0F0F0F0FuLL;
-    /* Every 8 bits holds the sum of every 8-set of bits (4 significant bits) (8) */
-    su_int x = (su_int)(x2 + (x2 >> 32));
-    /* The lower 32 bits hold four 16 bit sums (5 significant bits). */
-    /*   Upper 32 bits are garbage */
-    x = x + (x >> 16);
-    /* The lower 16 bits hold two 32 bit sums (6 significant bits). */
-    /*   Upper 16 bits are garbage */
-    return (x + (x >> 8)) & 0x0000007F;  /* (7 significant bits) */
+COMPILER_RT_ABI int __popcountdi2(di_int a) {
+  du_int x2 = (du_int)a;
+  x2 = x2 - ((x2 >> 1) & 0x5555555555555555uLL);
+  // Every 2 bits holds the sum of every pair of bits (32)
+  x2 = ((x2 >> 2) & 0x3333333333333333uLL) + (x2 & 0x3333333333333333uLL);
+  // Every 4 bits holds the sum of every 4-set of bits (3 significant bits) (16)
+  x2 = (x2 + (x2 >> 4)) & 0x0F0F0F0F0F0F0F0FuLL;
+  // Every 8 bits holds the sum of every 8-set of bits (4 significant bits) (8)
+  su_int x = (su_int)(x2 + (x2 >> 32));
+  // The lower 32 bits hold four 16 bit sums (5 significant bits).
+  //   Upper 32 bits are garbage
+  x = x + (x >> 16);
+  // The lower 16 bits hold two 32 bit sums (6 significant bits).
+  //   Upper 16 bits are garbage
+  return (x + (x >> 8)) & 0x0000007F; // (7 significant bits)
 }
diff --git a/lib/compiler-rt/builtins/popcountsi2.c b/lib/compiler-rt/builtins/popcountsi2.c
index 44544ff49..4d346c45d 100644
--- a/lib/compiler-rt/builtins/popcountsi2.c
+++ b/lib/compiler-rt/builtins/popcountsi2.c
@@ -1,33 +1,29 @@
-/* ===-- popcountsi2.c - Implement __popcountsi2 ---------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __popcountsi2 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- popcountsi2.c - Implement __popcountsi2 ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __popcountsi2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: count of 1 bits */
+// Returns: count of 1 bits
 
-COMPILER_RT_ABI si_int
-__popcountsi2(si_int a)
-{
-    su_int x = (su_int)a;
-    x = x - ((x >> 1) & 0x55555555);
-    /* Every 2 bits holds the sum of every pair of bits */
-    x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
-    /* Every 4 bits holds the sum of every 4-set of bits (3 significant bits) */
-    x = (x + (x >> 4)) & 0x0F0F0F0F;
-    /* Every 8 bits holds the sum of every 8-set of bits (4 significant bits) */
-    x = (x + (x >> 16));
-    /* The lower 16 bits hold two 8 bit sums (5 significant bits).*/
-    /*    Upper 16 bits are garbage */
-    return (x + (x >> 8)) & 0x0000003F;  /* (6 significant bits) */
+COMPILER_RT_ABI int __popcountsi2(si_int a) {
+  su_int x = (su_int)a;
+  x = x - ((x >> 1) & 0x55555555);
+  // Every 2 bits holds the sum of every pair of bits
+  x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
+  // Every 4 bits holds the sum of every 4-set of bits (3 significant bits)
+  x = (x + (x >> 4)) & 0x0F0F0F0F;
+  // Every 8 bits holds the sum of every 8-set of bits (4 significant bits)
+  x = (x + (x >> 16));
+  // The lower 16 bits hold two 8 bit sums (5 significant bits).
+  //    Upper 16 bits are garbage
+  return (x + (x >> 8)) & 0x0000003F; // (6 significant bits)
 }
diff --git a/lib/compiler-rt/builtins/udivmoddi4.c b/lib/compiler-rt/builtins/udivmoddi4.c
index 0c8b4ff46..123e5fb05 100644
--- a/lib/compiler-rt/builtins/udivmoddi4.c
+++ b/lib/compiler-rt/builtins/udivmoddi4.c
@@ -1,231 +1,200 @@
-/* ===-- udivmoddi4.c - Implement __udivmoddi4 -----------------------------===
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is dual licensed under the MIT and the University of Illinois Open
- * Source Licenses. See LICENSE.TXT for details.
- *
- * ===----------------------------------------------------------------------===
- *
- * This file implements __udivmoddi4 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- udivmoddi4.c - Implement __udivmoddi4 -----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __udivmoddi4 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Effects: if rem != 0, *rem = a % b
- * Returns: a / b
- */
+// Effects: if rem != 0, *rem = a % b
+// Returns: a / b
 
-/* Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide */
+// Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide
 
-COMPILER_RT_ABI du_int
-__udivmoddi4(du_int a, du_int b, du_int* rem)
-{
-    const unsigned n_uword_bits = sizeof(su_int) * CHAR_BIT;
-    const unsigned n_udword_bits = sizeof(du_int) * CHAR_BIT;
-    udwords n;
-    n.all = a;
-    udwords d;
-    d.all = b;
-    udwords q;
-    udwords r;
-    unsigned sr;
-    /* special cases, X is unknown, K != 0 */
-    if (n.s.high == 0)
-    {
-        if (d.s.high == 0)
-        {
-            /* 0 X
-             * ---
-             * 0 X
-             */
-            if (rem)
-                *rem = n.s.low % d.s.low;
-            return n.s.low / d.s.low;
-        }
-        /* 0 X
-         * ---
-         * K X
-         */
-        if (rem)
-            *rem = n.s.low;
-        return 0;
+#if defined(_MSC_VER) && !defined(__clang__)
+// MSVC throws a warning about mod 0 here, disable it for builds that
+// warn-as-error
+#pragma warning(push)
+#pragma warning(disable : 4723 4724)
+#endif
+
+COMPILER_RT_ABI du_int __udivmoddi4(du_int a, du_int b, du_int *rem) {
+  const unsigned n_uword_bits = sizeof(su_int) * CHAR_BIT;
+  const unsigned n_udword_bits = sizeof(du_int) * CHAR_BIT;
+  udwords n;
+  n.all = a;
+  udwords d;
+  d.all = b;
+  udwords q;
+  udwords r;
+  unsigned sr;
+  // special cases, X is unknown, K != 0
+  if (n.s.high == 0) {
+    if (d.s.high == 0) {
+      // 0 X
+      // ---
+      // 0 X
+      if (rem)
+        *rem = n.s.low % d.s.low;
+      return n.s.low / d.s.low;
     }
-    /* n.s.high != 0 */
-    if (d.s.low == 0)
-    {
-        if (d.s.high == 0)
-        {
-            /* K X
-             * ---
-             * 0 0
-             */ 
-            if (rem)
-                *rem = n.s.high % d.s.low;
-            return n.s.high / d.s.low;
-        }
-        /* d.s.high != 0 */
-        if (n.s.low == 0)
-        {
-            /* K 0
-             * ---
-             * K 0
-             */
-            if (rem)
-            {
-                r.s.high = n.s.high % d.s.high;
-                r.s.low = 0;
-                *rem = r.all;
-            }
-            return n.s.high / d.s.high;
-        }
-        /* K K
-         * ---
-         * K 0
-         */
-        if ((d.s.high & (d.s.high - 1)) == 0)     /* if d is a power of 2 */
-        {
-            if (rem)
-            {
-                r.s.low = n.s.low;
-                r.s.high = n.s.high & (d.s.high - 1);
-                *rem = r.all;
-            }
-            return n.s.high >> __builtin_ctz(d.s.high);
-        }
-        /* K K
-         * ---
-         * K 0
-         */
-        sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high);
-        /* 0 <= sr <= n_uword_bits - 2 or sr large */
-        if (sr > n_uword_bits - 2)
-        {
-           if (rem)
-                *rem = n.all;
-            return 0;
-        }
-        ++sr;
-        /* 1 <= sr <= n_uword_bits - 1 */
-        /* q.all = n.all << (n_udword_bits - sr); */
+    // 0 X
+    // ---
+    // K X
+    if (rem)
+      *rem = n.s.low;
+    return 0;
+  }
+  // n.s.high != 0
+  if (d.s.low == 0) {
+    if (d.s.high == 0) {
+      // K X
+      // ---
+      // 0 0
+      if (rem)
+        *rem = n.s.high % d.s.low;
+      return n.s.high / d.s.low;
+    }
+    // d.s.high != 0
+    if (n.s.low == 0) {
+      // K 0
+      // ---
+      // K 0
+      if (rem) {
+        r.s.high = n.s.high % d.s.high;
+        r.s.low = 0;
+        *rem = r.all;
+      }
+      return n.s.high / d.s.high;
+    }
+    // K K
+    // ---
+    // K 0
+    if ((d.s.high & (d.s.high - 1)) == 0) /* if d is a power of 2 */ {
+      if (rem) {
+        r.s.low = n.s.low;
+        r.s.high = n.s.high & (d.s.high - 1);
+        *rem = r.all;
+      }
+      return n.s.high >> ctzsi(d.s.high);
+    }
+    // K K
+    // ---
+    // K 0
+    sr = clzsi(d.s.high) - clzsi(n.s.high);
+    // 0 <= sr <= n_uword_bits - 2 or sr large
+    if (sr > n_uword_bits - 2) {
+      if (rem)
+        *rem = n.all;
+      return 0;
+    }
+    ++sr;
+    // 1 <= sr <= n_uword_bits - 1
+    // q.all = n.all << (n_udword_bits - sr);
+    q.s.low = 0;
+    q.s.high = n.s.low << (n_uword_bits - sr);
+    // r.all = n.all >> sr;
+    r.s.high = n.s.high >> sr;
+    r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+  } else /* d.s.low != 0 */ {
+    if (d.s.high == 0) {
+      // K X
+      // ---
+      // 0 K
+      if ((d.s.low & (d.s.low - 1)) == 0) /* if d is a power of 2 */ {
+        if (rem)
+          *rem = n.s.low & (d.s.low - 1);
+        if (d.s.low == 1)
+          return n.all;
+        sr = ctzsi(d.s.low);
+        q.s.high = n.s.high >> sr;
+        q.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+        return q.all;
+      }
+      // K X
+      // ---
+      // 0 K
+      sr = 1 + n_uword_bits + clzsi(d.s.low) - clzsi(n.s.high);
+      // 2 <= sr <= n_udword_bits - 1
+      // q.all = n.all << (n_udword_bits - sr);
+      // r.all = n.all >> sr;
+      if (sr == n_uword_bits) {
+        q.s.low = 0;
+        q.s.high = n.s.low;
+        r.s.high = 0;
+        r.s.low = n.s.high;
+      } else if (sr < n_uword_bits) /* 2 <= sr <= n_uword_bits - 1 */ {
         q.s.low = 0;
         q.s.high = n.s.low << (n_uword_bits - sr);
-        /* r.all = n.all >> sr; */
         r.s.high = n.s.high >> sr;
         r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+      } else /* n_uword_bits + 1 <= sr <= n_udword_bits - 1 */ {
+        q.s.low = n.s.low << (n_udword_bits - sr);
+        q.s.high = (n.s.high << (n_udword_bits - sr)) |
+                   (n.s.low >> (sr - n_uword_bits));
+        r.s.high = 0;
+        r.s.low = n.s.high >> (sr - n_uword_bits);
+      }
+    } else {
+      // K X
+      // ---
+      // K K
+      sr = clzsi(d.s.high) - clzsi(n.s.high);
+      // 0 <= sr <= n_uword_bits - 1 or sr large
+      if (sr > n_uword_bits - 1) {
+        if (rem)
+          *rem = n.all;
+        return 0;
+      }
+      ++sr;
+      // 1 <= sr <= n_uword_bits
+      // q.all = n.all << (n_udword_bits - sr);
+      q.s.low = 0;
+      if (sr == n_uword_bits) {
+        q.s.high = n.s.low;
+        r.s.high = 0;
+        r.s.low = n.s.high;
+      } else {
+        q.s.high = n.s.low << (n_uword_bits - sr);
+        r.s.high = n.s.high >> sr;
+        r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+      }
     }
-    else  /* d.s.low != 0 */
-    {
-        if (d.s.high == 0)
-        {
-            /* K X
-             * ---
-             * 0 K
-             */
-            if ((d.s.low & (d.s.low - 1)) == 0)     /* if d is a power of 2 */
-            {
-                if (rem)
-                    *rem = n.s.low & (d.s.low - 1);
-                if (d.s.low == 1)
-                    return n.all;
-                sr = __builtin_ctz(d.s.low);
-                q.s.high = n.s.high >> sr;
-                q.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
-                return q.all;
-            }
-            /* K X
-             * ---
-             * 0 K
-             */
-            sr = 1 + n_uword_bits + __builtin_clz(d.s.low) - __builtin_clz(n.s.high);
-            /* 2 <= sr <= n_udword_bits - 1
-             * q.all = n.all << (n_udword_bits - sr);
-             * r.all = n.all >> sr;
-             */
-            if (sr == n_uword_bits)
-            {
-                q.s.low = 0;
-                q.s.high = n.s.low;
-                r.s.high = 0;
-                r.s.low = n.s.high;
-            }
-            else if (sr < n_uword_bits)  // 2 <= sr <= n_uword_bits - 1
-            {
-                q.s.low = 0;
-                q.s.high = n.s.low << (n_uword_bits - sr);
-                r.s.high = n.s.high >> sr;
-                r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
-            }
-            else              // n_uword_bits + 1 <= sr <= n_udword_bits - 1
-            {
-                q.s.low = n.s.low << (n_udword_bits - sr);
-                q.s.high = (n.s.high << (n_udword_bits - sr)) |
-                           (n.s.low >> (sr - n_uword_bits));
-                r.s.high = 0;
-                r.s.low = n.s.high >> (sr - n_uword_bits);
-            }
-        }
-        else
-        {
-            /* K X
-             * ---
-             * K K
-             */
-            sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high);
-            /* 0 <= sr <= n_uword_bits - 1 or sr large */
-            if (sr > n_uword_bits - 1)
-            {
-                if (rem)
-                    *rem = n.all;
-                return 0;
-            }
-            ++sr;
-            /* 1 <= sr <= n_uword_bits */
-            /*  q.all = n.all << (n_udword_bits - sr); */
-            q.s.low = 0;
-            if (sr == n_uword_bits)
-            {
-                q.s.high = n.s.low;
-                r.s.high = 0;
-                r.s.low = n.s.high;
-            }
-            else
-            {
-                q.s.high = n.s.low << (n_uword_bits - sr);
-                r.s.high = n.s.high >> sr;
-                r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
-            }
-        }
-    }
-    /* Not a special case
-     * q and r are initialized with:
-     * q.all = n.all << (n_udword_bits - sr);
-     * r.all = n.all >> sr;
-     * 1 <= sr <= n_udword_bits - 1
-     */
-    su_int carry = 0;
-    for (; sr > 0; --sr)
-    {
-        /* r:q = ((r:q)  << 1) | carry */
-        r.s.high = (r.s.high << 1) | (r.s.low  >> (n_uword_bits - 1));
-        r.s.low  = (r.s.low  << 1) | (q.s.high >> (n_uword_bits - 1));
-        q.s.high = (q.s.high << 1) | (q.s.low  >> (n_uword_bits - 1));
-        q.s.low  = (q.s.low  << 1) | carry;
-        /* carry = 0;
-         * if (r.all >= d.all)
-         * {
-         *      r.all -= d.all;
-         *      carry = 1;
-         * }
-         */
-        const di_int s = (di_int)(d.all - r.all - 1) >> (n_udword_bits - 1);
-        carry = s & 1;
-        r.all -= d.all & s;
-    }
-    q.all = (q.all << 1) | carry;
-    if (rem)
-        *rem = r.all;
-    return q.all;
+  }
+  // Not a special case
+  // q and r are initialized with:
+  // q.all = n.all << (n_udword_bits - sr);
+  // r.all = n.all >> sr;
+  // 1 <= sr <= n_udword_bits - 1
+  su_int carry = 0;
+  for (; sr > 0; --sr) {
+    // r:q = ((r:q)  << 1) | carry
+    r.s.high = (r.s.high << 1) | (r.s.low >> (n_uword_bits - 1));
+    r.s.low = (r.s.low << 1) | (q.s.high >> (n_uword_bits - 1));
+    q.s.high = (q.s.high << 1) | (q.s.low >> (n_uword_bits - 1));
+    q.s.low = (q.s.low << 1) | carry;
+    // carry = 0;
+    // if (r.all >= d.all)
+    // {
+    //      r.all -= d.all;
+    //      carry = 1;
+    // }
+    const di_int s = (di_int)(d.all - r.all - 1) >> (n_udword_bits - 1);
+    carry = s & 1;
+    r.all -= d.all & s;
+  }
+  q.all = (q.all << 1) | carry;
+  if (rem)
+    *rem = r.all;
+  return q.all;
 }
+
+#if defined(_MSC_VER) && !defined(__clang__)
+#pragma warning(pop)
+#endif