Get aarch64 hello world working

$ m=aarch64-tiny
    $ make -j8 m=$m o/$m/tool/hello/hello.com o/third_party/qemu/qemu-aarch64
    $ o/third_party/qemu/qemu-aarch64 o/$m/tool/hello/hello.com
    hello world
    $ ls -hal o/$m/tool/hello/hello.com
    -rwxr-xr-x 1 jart jart 4.0K May  9 05:04 o/aarch64-tiny/tool/hello/hello.com

libc/intrin/asan.c

@@ -1021,9 +1021,9 @@ static void __asan_trace(struct AsanTrace *bt, const struct StackFrame *bp) {
     }
     if (!__asan_checka(SHADOW(bp), sizeof(*bp) >> 3).kind) {
       addr = bp->addr;
-      if (addr == _weakaddr("__gc") && _weakaddr("__gc")) {
+      if (addr == (uintptr_t)_weaken(__gc) && (uintptr_t)_weaken(__gc)) {
         do --gi;
-        while ((addr = garbage->p[gi].ret) == _weakaddr("__gc"));
+        while ((addr = garbage->p[gi].ret) == (uintptr_t)_weaken(__gc));
       }
       bt->p[i] = addr;
     } else {

libc/intrin/ashlti3.c

@@ -0,0 +1,46 @@
+/* clang-format off */
+/* ===-- ashlti3.c - Implement __ashlti3 -----------------------------------===
+ *
+ *                     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 __ashlti3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "third_party/compiler_rt/int_lib.h"
+
+#ifdef CRT_HAS_128BIT
+
+/* Returns: a << b */
+
+/* Precondition:  0 <= b < bits_in_tword */
+
+COMPILER_RT_ABI ti_int
+__ashlti3(ti_int a, si_int b)
+{
+    const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
+    twords input;
+    twords result;
+    input.all = a;
+    if (b & bits_in_dword)  /* bits_in_dword <= b < bits_in_tword */
+    {
+        result.s.low = 0;
+        result.s.high = input.s.low << (b - bits_in_dword);
+    }
+    else  /* 0 <= b < bits_in_dword */
+    {
+        if (b == 0)
+            return a;
+        result.s.low  = input.s.low << b;
+        result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_dword - b));
+    }
+    return result.all;
+}
+
+#endif /* CRT_HAS_128BIT */

libc/intrin/exit.c

@@ -36,7 +36,7 @@
  * @vforksafe
  * @noreturn
  */
-privileged wontreturn void _Exit(int exitcode) {
+wontreturn void _Exit(int exitcode) {
   int i;
   STRACE("_Exit(%d)", exitcode);
 #ifdef __x86_64__
@@ -67,7 +67,7 @@ privileged wontreturn void _Exit(int exitcode) {
   for (;;) asm("ud2");
 #elif defined(__aarch64__)
   register long x0 asm("x0") = exitcode;
-  asm volatile("mov\tx8,%1\n\t"
+  asm volatile("mov\tx8,%0\n\t"
                "svc\t0"
                : /* no outputs */
                : "i"(94), "r"(x0)

libc/intrin/exit1.greg.c

@@ -75,7 +75,7 @@ privileged wontreturn void _Exit1(int rc) {
   notpossible;
 #elif defined(__aarch64__)
   register long r0 asm("x0") = rc;
-  asm volatile("mov\tx8,%1\n\t"
+  asm volatile("mov\tx8,%0\n\t"
                "svc\t0"
                : /* no outputs */
                : "i"(93), "r"(r0)

libc/intrin/exitr.c

@@ -16,9 +16,12 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
 #include "libc/runtime/runtime.h"
 
-privileged wontreturn void _Exitr(int exitcode) {
+wontreturn void _Exitr(int exitcode) {
+#if SupportsWindows()
   _restorewintty();
+#endif
   _Exit(exitcode);
 }

libc/intrin/ezlea.h

@@ -1,12 +0,0 @@
-#ifndef COSMOPOLITAN_LIBC_BITS_EZLEA_H_
-#define COSMOPOLITAN_LIBC_BITS_EZLEA_H_
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
-
-#if __pic__ + __pie__ + __code_model_medium__ + __code_model_large__ + 0 > 1
-#define _ezlea(symbol) "lea\t" symbol "(%%rip),%"
-#else
-#define _ezlea(symbol) "mov\t$" symbol ",%k"
-#endif
-
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_BITS_EZLEA_H_ */

libc/intrin/fenv.S

@@ -29,7 +29,7 @@
 
 feclearexcept:
 #ifdef __x86_64__
-	# maintain exceptions in the sse mxcsr, clear x87 exceptions
+//	maintain exceptions in the sse mxcsr, clear x87 exceptions
 	mov	%edi,%ecx
 	and	$0x3f,%ecx
 	fnstsw	%ax

libc/intrin/restorewintty.c

@@ -35,7 +35,7 @@ const unsigned char kConsoleHandles[3] = {
 };
 
 // Puts cmd.exe gui back the way it was.
-privileged noinstrument void _restorewintty(void) {
+noinstrument void _restorewintty(void) {
   if (!IsWindows()) return;
   if (__imp_GetCurrentProcessId() != __pid_exec) return;
   for (int i = 0; i < 3; ++i) {

libc/intrin/sched_yield.S

@@ -91,7 +91,6 @@ sched_yield:
 #elif defined(__aarch64__)
 	mov	x8,#0x7c
 	svc	0
-	mov	w0,#0
 	ret
 
 #else

libc/intrin/weaken.h

@@ -1,33 +1,12 @@
 #ifndef COSMOPOLITAN_LIBC_BITS_WEAKEN_H_
 #define COSMOPOLITAN_LIBC_BITS_WEAKEN_H_
-#include "libc/intrin/ezlea.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
-#ifndef __STRICT_ANSI__
 
-#define _weaken(symbol)                \
-  ({                                   \
-    typeof(&symbol) _p = &symbol;      \
-    asm(".weak\t" #symbol : "+r"(_p)); \
-    _p;                                \
+#define _weaken(symbol)                                         \
+  __extension__({                                               \
+    extern __typeof__(symbol) symbol __attribute__((__weak__)); \
+    &symbol;                                                    \
   })
 
-#define _strongaddr(symbolstr)                \
-  ({                                          \
-    intptr_t waddr;                           \
-    asm(_ezlea(symbolstr) "0" : "=r"(waddr)); \
-    waddr;                                    \
-  })
-
-#define _weakaddr(symbolstr)                                             \
-  ({                                                                     \
-    intptr_t waddr;                                                      \
-    asm(".weak\t" symbolstr "\n\t" _ezlea(symbolstr) "0" : "=r"(waddr)); \
-    waddr;                                                               \
-  })
-
-#else
-#define _weaken(symbol)      symbol
-#define _weakaddr(symbolstr) &(symbolstr)
-#endif /* __STRICT_ANSI__ */
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_LIBC_BITS_WEAKEN_H_ */