Make atomics faster on aarch64

This change implements the compiler runtime for ARM v8.1 ISE atomics and
gets rid of the mandatory -mno-outline-atomics flag. It can dramatically
speed things up, on newer ARM CPUs, as indicated by the changed lines in
test/libc/thread/footek_test.c. In llamafile dispatching on hwcap atomic
also shaved microseconds off synchronization barriers.
This commit is contained in:
Justine Tunney 2024-08-16 11:05:37 -07:00
parent de0cde8def
commit 11d9fb521d
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GPG key ID: BE714B4575D6E328
12 changed files with 2053 additions and 71 deletions

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@ -131,7 +131,7 @@ elif [ x"$ARCH" = x"aarch64" ]; then
OBJCOPYFLAGS="-S"
PAGESZ=16384
CPPFLAGS="$CPPFLAGS -fsigned-char"
CFLAGS="$CFLAGS -ffixed-x18 -ffixed-x28 -mno-outline-atomics"
CFLAGS="$CFLAGS -ffixed-x18 -ffixed-x28"
LDFLAGS="$LDFLAGS -Wl,-T,$LIB/aarch64.lds"
else
fatal_error "$ARCH: unsupported architecture"