From 56172fcd8bd045e38bbdf76697d1fcca1e965d6d Mon Sep 17 00:00:00 2001
From: Alex Huszagh <ahuszagh@gmail.com>
Date: Fri, 29 Jul 2022 16:58:05 -0500
Subject: [PATCH] Add compiler-rt fallbacks for sync builtins on armv5te-musl.

---
https://github.com/rust-lang/compiler-builtins/pull/484

 src/arm_linux.rs | 110 +++++++++++++++++++++++++++++++----------------
 1 file changed, 73 insertions(+), 37 deletions(-)

diff --git a/vendor/compiler_builtins/src/arm_linux.rs b/vendor/compiler_builtins/src/arm_linux.rs
index 8fe0948..8f22eb6 100644
--- a/vendor/compiler_builtins/src/arm_linux.rs
+++ b/vendor/compiler_builtins/src/arm_linux.rs
@@ -55,7 +55,7 @@ fn insert_aligned(aligned: u32, val: u32, shift: u32, mask: u32) -> u32 {
 }
 
 // Generic atomic read-modify-write operation
-unsafe fn atomic_rmw<T, F: Fn(u32) -> u32>(ptr: *mut T, f: F) -> u32 {
+unsafe fn atomic_rmw<T, F: Fn(u32) -> u32, G: Fn(u32, u32) -> u32>(ptr: *mut T, f: F, g: G) -> u32 {
     let aligned_ptr = align_ptr(ptr);
     let (shift, mask) = get_shift_mask(ptr);
 
@@ -65,7 +65,7 @@ unsafe fn atomic_rmw<T, F: Fn(u32) -> u32>(ptr: *mut T, f: F) -> u32 {
         let newval = f(curval);
         let newval_aligned = insert_aligned(curval_aligned, newval, shift, mask);
         if __kuser_cmpxchg(curval_aligned, newval_aligned, aligned_ptr) {
-            return curval;
+            return g(curval, newval);
         }
     }
 }
@@ -89,13 +89,21 @@ unsafe fn atomic_cmpxchg<T>(ptr: *mut T, oldval: u32, newval: u32) -> u32 {
 }
 
 macro_rules! atomic_rmw {
-    ($name:ident, $ty:ty, $op:expr) => {
+    ($name:ident, $ty:ty, $op:expr, $fetch:expr) => {
         intrinsics! {
             pub unsafe extern "C" fn $name(ptr: *mut $ty, val: $ty) -> $ty {
-                atomic_rmw(ptr, |x| $op(x as $ty, val) as u32) as $ty
+                atomic_rmw(ptr, |x| $op(x as $ty, val) as u32, |old, new| $fetch(old, new)) as $ty
             }
         }
     };
+
+    (@old $name:ident, $ty:ty, $op:expr) => {
+        atomic_rmw!($name, $ty, $op, |old, _| old);
+    };
+
+    (@new $name:ident, $ty:ty, $op:expr) => {
+        atomic_rmw!($name, $ty, $op, |_, new| new);
+    };
 }
 macro_rules! atomic_cmpxchg {
     ($name:ident, $ty:ty) => {
@@ -107,101 +115,129 @@ macro_rules! atomic_cmpxchg {
     };
 }
 
-atomic_rmw!(__sync_fetch_and_add_1, u8, |a: u8, b: u8| a.wrapping_add(b));
-atomic_rmw!(__sync_fetch_and_add_2, u16, |a: u16, b: u16| a
+atomic_rmw!(@old __sync_fetch_and_add_1, u8, |a: u8, b: u8| a.wrapping_add(b));
+atomic_rmw!(@old __sync_fetch_and_add_2, u16, |a: u16, b: u16| a
+    .wrapping_add(b));
+atomic_rmw!(@old __sync_fetch_and_add_4, u32, |a: u32, b: u32| a
+    .wrapping_add(b));
+
+atomic_rmw!(@new __sync_add_and_fetch_1, u8, |a: u8, b: u8| a.wrapping_add(b));
+atomic_rmw!(@new __sync_add_and_fetch_2, u16, |a: u16, b: u16| a
     .wrapping_add(b));
-atomic_rmw!(__sync_fetch_and_add_4, u32, |a: u32, b: u32| a
+atomic_rmw!(@new __sync_add_and_fetch_4, u32, |a: u32, b: u32| a
     .wrapping_add(b));
 
-atomic_rmw!(__sync_fetch_and_sub_1, u8, |a: u8, b: u8| a.wrapping_sub(b));
-atomic_rmw!(__sync_fetch_and_sub_2, u16, |a: u16, b: u16| a
+atomic_rmw!(@old __sync_fetch_and_sub_1, u8, |a: u8, b: u8| a.wrapping_sub(b));
+atomic_rmw!(@old __sync_fetch_and_sub_2, u16, |a: u16, b: u16| a
     .wrapping_sub(b));
-atomic_rmw!(__sync_fetch_and_sub_4, u32, |a: u32, b: u32| a
+atomic_rmw!(@old __sync_fetch_and_sub_4, u32, |a: u32, b: u32| a
     .wrapping_sub(b));
 
-atomic_rmw!(__sync_fetch_and_and_1, u8, |a: u8, b: u8| a & b);
-atomic_rmw!(__sync_fetch_and_and_2, u16, |a: u16, b: u16| a & b);
-atomic_rmw!(__sync_fetch_and_and_4, u32, |a: u32, b: u32| a & b);
+atomic_rmw!(@new __sync_sub_and_fetch_1, u8, |a: u8, b: u8| a.wrapping_sub(b));
+atomic_rmw!(@new __sync_sub_and_fetch_2, u16, |a: u16, b: u16| a
+    .wrapping_sub(b));
+atomic_rmw!(@new __sync_sub_and_fetch_4, u32, |a: u32, b: u32| a
+    .wrapping_sub(b));
+
+atomic_rmw!(@old __sync_fetch_and_and_1, u8, |a: u8, b: u8| a & b);
+atomic_rmw!(@old __sync_fetch_and_and_2, u16, |a: u16, b: u16| a & b);
+atomic_rmw!(@old __sync_fetch_and_and_4, u32, |a: u32, b: u32| a & b);
+
+atomic_rmw!(@new __sync_and_and_fetch_1, u8, |a: u8, b: u8| a & b);
+atomic_rmw!(@new __sync_and_and_fetch_2, u16, |a: u16, b: u16| a & b);
+atomic_rmw!(@new __sync_and_and_fetch_4, u32, |a: u32, b: u32| a & b);
+
+atomic_rmw!(@old __sync_fetch_and_or_1, u8, |a: u8, b: u8| a | b);
+atomic_rmw!(@old __sync_fetch_and_or_2, u16, |a: u16, b: u16| a | b);
+atomic_rmw!(@old __sync_fetch_and_or_4, u32, |a: u32, b: u32| a | b);
+
+atomic_rmw!(@new __sync_or_and_fetch_1, u8, |a: u8, b: u8| a | b);
+atomic_rmw!(@new __sync_or_and_fetch_2, u16, |a: u16, b: u16| a | b);
+atomic_rmw!(@new __sync_or_and_fetch_4, u32, |a: u32, b: u32| a | b);
+
+atomic_rmw!(@old __sync_fetch_and_xor_1, u8, |a: u8, b: u8| a ^ b);
+atomic_rmw!(@old __sync_fetch_and_xor_2, u16, |a: u16, b: u16| a ^ b);
+atomic_rmw!(@old __sync_fetch_and_xor_4, u32, |a: u32, b: u32| a ^ b);
 
-atomic_rmw!(__sync_fetch_and_or_1, u8, |a: u8, b: u8| a | b);
-atomic_rmw!(__sync_fetch_and_or_2, u16, |a: u16, b: u16| a | b);
-atomic_rmw!(__sync_fetch_and_or_4, u32, |a: u32, b: u32| a | b);
+atomic_rmw!(@new __sync_xor_and_fetch_1, u8, |a: u8, b: u8| a ^ b);
+atomic_rmw!(@new __sync_xor_and_fetch_2, u16, |a: u16, b: u16| a ^ b);
+atomic_rmw!(@new __sync_xor_and_fetch_4, u32, |a: u32, b: u32| a ^ b);
 
-atomic_rmw!(__sync_fetch_and_xor_1, u8, |a: u8, b: u8| a ^ b);
-atomic_rmw!(__sync_fetch_and_xor_2, u16, |a: u16, b: u16| a ^ b);
-atomic_rmw!(__sync_fetch_and_xor_4, u32, |a: u32, b: u32| a ^ b);
+atomic_rmw!(@old __sync_fetch_and_nand_1, u8, |a: u8, b: u8| !(a & b));
+atomic_rmw!(@old __sync_fetch_and_nand_2, u16, |a: u16, b: u16| !(a & b));
+atomic_rmw!(@old __sync_fetch_and_nand_4, u32, |a: u32, b: u32| !(a & b));
 
-atomic_rmw!(__sync_fetch_and_nand_1, u8, |a: u8, b: u8| !(a & b));
-atomic_rmw!(__sync_fetch_and_nand_2, u16, |a: u16, b: u16| !(a & b));
-atomic_rmw!(__sync_fetch_and_nand_4, u32, |a: u32, b: u32| !(a & b));
+atomic_rmw!(@new __sync_nand_and_fetch_1, u8, |a: u8, b: u8| !(a & b));
+atomic_rmw!(@new __sync_nand_and_fetch_2, u16, |a: u16, b: u16| !(a & b));
+atomic_rmw!(@new __sync_nand_and_fetch_4, u32, |a: u32, b: u32| !(a & b));
 
-atomic_rmw!(__sync_fetch_and_max_1, i8, |a: i8, b: i8| if a > b {
+atomic_rmw!(@old __sync_fetch_and_max_1, i8, |a: i8, b: i8| if a > b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_max_2, i16, |a: i16, b: i16| if a > b {
+atomic_rmw!(@old __sync_fetch_and_max_2, i16, |a: i16, b: i16| if a > b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_max_4, i32, |a: i32, b: i32| if a > b {
+atomic_rmw!(@old __sync_fetch_and_max_4, i32, |a: i32, b: i32| if a > b {
     a
 } else {
     b
 });
 
-atomic_rmw!(__sync_fetch_and_umax_1, u8, |a: u8, b: u8| if a > b {
+atomic_rmw!(@old __sync_fetch_and_umax_1, u8, |a: u8, b: u8| if a > b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_umax_2, u16, |a: u16, b: u16| if a > b {
+atomic_rmw!(@old __sync_fetch_and_umax_2, u16, |a: u16, b: u16| if a > b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_umax_4, u32, |a: u32, b: u32| if a > b {
+atomic_rmw!(@old __sync_fetch_and_umax_4, u32, |a: u32, b: u32| if a > b {
     a
 } else {
     b
 });
 
-atomic_rmw!(__sync_fetch_and_min_1, i8, |a: i8, b: i8| if a < b {
+atomic_rmw!(@old __sync_fetch_and_min_1, i8, |a: i8, b: i8| if a < b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_min_2, i16, |a: i16, b: i16| if a < b {
+atomic_rmw!(@old __sync_fetch_and_min_2, i16, |a: i16, b: i16| if a < b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_min_4, i32, |a: i32, b: i32| if a < b {
+atomic_rmw!(@old __sync_fetch_and_min_4, i32, |a: i32, b: i32| if a < b {
     a
 } else {
     b
 });
 
-atomic_rmw!(__sync_fetch_and_umin_1, u8, |a: u8, b: u8| if a < b {
+atomic_rmw!(@old __sync_fetch_and_umin_1, u8, |a: u8, b: u8| if a < b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_umin_2, u16, |a: u16, b: u16| if a < b {
+atomic_rmw!(@old __sync_fetch_and_umin_2, u16, |a: u16, b: u16| if a < b {
     a
 } else {
     b
 });
-atomic_rmw!(__sync_fetch_and_umin_4, u32, |a: u32, b: u32| if a < b {
+atomic_rmw!(@old __sync_fetch_and_umin_4, u32, |a: u32, b: u32| if a < b {
     a
 } else {
     b
 });
 
-atomic_rmw!(__sync_lock_test_and_set_1, u8, |_: u8, b: u8| b);
-atomic_rmw!(__sync_lock_test_and_set_2, u16, |_: u16, b: u16| b);
-atomic_rmw!(__sync_lock_test_and_set_4, u32, |_: u32, b: u32| b);
+atomic_rmw!(@old __sync_lock_test_and_set_1, u8, |_: u8, b: u8| b);
+atomic_rmw!(@old __sync_lock_test_and_set_2, u16, |_: u16, b: u16| b);
+atomic_rmw!(@old __sync_lock_test_and_set_4, u32, |_: u32, b: u32| b);
 
 atomic_cmpxchg!(__sync_val_compare_and_swap_1, u8);
 atomic_cmpxchg!(__sync_val_compare_and_swap_2, u16);
-- 
2.39.0