Port a lot more code to AARCH64

- Introduce epoll_pwait()
- Rewrite -ftrapv and ffs() libraries in C code
- Use more FreeBSD code in math function library
- Get significantly more tests passing on qemu-aarch64
- Fix many Musl long double functions that were broken on AARCH64

tool/decode/x87.c

@@ -1,135 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/math.h"
-#include "libc/mem/gc.internal.h"
-#include "libc/stdio/stdio.h"
-#include "libc/str/str.h"
-#include "libc/x/x.h"
-#include "third_party/gdtoa/gdtoa.h"
-
-const char kConfig[] = "\
-/* FPU Control Word (x87) Exception Masks\n\
-   @see Intel Manual V1 §8.1.5\n\
-       IM: Invalid Operation ───────────────┐\n\
-       DM: Denormal Operand ───────────────┐│\n\
-       ZM: Zero Divide ───────────────────┐││\n\
-       OM: Overflow ─────────────────────┐│││\n\
-       UM: Underflow ───────────────────┐││││\n\
-       PM: Precision ──────────────────┐│││││\n\
-      PC: Precision Control ────────┐  ││││││\n\
-       {float,∅,double,long double} │  ││││││\n\
-      RC: Rounding Control ───────┐ │  ││││││\n\
-       {even, →-∞, →+∞, →0}       │┌┤  ││││││\n\
-                                 ┌┤││  ││││││\n\
-                                d││││rr││││││*/\n\
-                          ";
-
-const char kStatus[] = "\
-/* FPU Status Word (x87)\n\
-   @see Intel Manual V1 §8.1.3\n\
-   IE: Invalid Operation ────────────────┐\n\
-   DE: Denormalized Operand ────────────┐│\n\
-   ZE: Zero Divide ────────────────────┐││\n\
-   OE: Overflow Flag ─────────────────┐│││\n\
-   UE: Underflow Flag ───────────────┐││││\n\
-   PE: Precision Flag ──────────────┐│││││\n\
-   SF: Stack Fault ────────────────┐││││││\n\
-   ES: Exception Summary Status ──┐│││││││\n\
-   C0-3: Condition Codes ──┬────┐ ││││││││\n\
-   TOP of Stack Pointer ─────┐  │ ││││││││\n\
-   B: FPU Busy ───────────┐│ │  │ ││││││││\n\
-                          ││┌┴┐┌┼┐││││││││\n\
-                          │↓│ │↓↓↓││││││││*/\n\
-                          ";
-
-const char kRegister[] = "\
-/\t┌sign\n\
-/\t│ ┌exponent\n\
-/\t│ │             ┌intpart\n\
-/\t│ │             │ ┌fraction\n\
-/\t│ │             │ │\n\
-/\t│┌┴────────────┐│┌┴────────────────────────────────────────────────────────────┐\n";
-
-void PrintRegister(long double x) {
-  char buf[32];
-  uint16_t lo, hi;
-  memcpy(buf, &x, sizeof(x));
-  memcpy(&lo, &buf[0], sizeof(lo));
-  memcpy(&hi, &buf[8], sizeof(hi));
-  g_xfmt_p(buf, &x, 15, 32, 0);
-  printf("/\t%016lb%064lb %s\n", hi, lo, buf);
-}
-
-int main(int argc, char *argv[]) {
-  double d;
-  unsigned short sw;
-  long double st0, st1;
-
-#define ST0 1
-#define ST1 2
-  d = 0;
-  st0 = ST0;
-  st1 = ST1;
-  asm("fstl\t%1\n\t"
-      "fstsw"
-      : "=a"(sw), "=m"(d) /*, "+t"(st0), "+u"(st1) */);
-  printf("\n%s%016b\n\n%s", kStatus, sw, kRegister);
-  PrintRegister(st0);
-  PrintRegister(st1);
-  printf("/\t%-80s %s\n", "d", gc(xdtoa(d)));
-
-#if 0
-#define ST0 2e18L
-#define ST1 0.0000000000000123L
-  st0 = ST0;
-  st1 = ST1;
-  asm("fldpi\n\t"
-      "fadd\t%%st\n\t"
-      "fxch\n2:\t"
-      "fprem1\n\t"
-      "fnstsw\n\t"
-      "test\t$4,%%ah\n\t"
-      "jnz\t2b\n\t"
-      "fstp\t%%st(1)\n\t"
-      "fsin\n\t"
-      "fstsw"
-      : "=a"(sw), "+t"(st0), "+u"(st1));
-  printf("\n%s%016b\n\n%s", kStatus, sw, kRegister);
-  PrintRegister(st0);
-  PrintRegister(st1);
-#endif
-
-#if 0
-  st0 = ST0;
-  st1 = ST1;
-  asm("fsin\n\t"
-      "fstsw"
-      : "=a"(sw), "+t"(st0), "+u"(st1));
-  printf("\n%s%016b\n\n%s", kStatus, sw, kRegister);
-  PrintRegister(st0);
-  PrintRegister(st1);
-#endif
-
-#if 0
-  printf("\n");
-  PrintRegister(sinl(remainderl(2e40L, M_PI * 2)));
-#endif
-
-  return 0;
-}