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

libc/nexgen32e/ffs.S

@@ -1,44 +0,0 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 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/macros.internal.h"
-
-//	Finds lowest set bit in word.
-//
-//	      uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
-//	    0x00000000      wut       32        0      wut       32
-//	    0x00000001        0        0        1        0       31
-//	    0x80000001        0        0        1       31        0
-//	    0x80000000       31       31       32       31        0
-//	    0x00000010        4        4        5        4       27
-//	    0x08000010        4        4        5       27        4
-//	    0x08000000       27       27       28       27        4
-//	    0xffffffff        0        0        1       31        0
-//
-//	@param	edi is the input number
-//	@return	number in range [1,32] or 0 if no bits set
-//	@see	also treasure trove of nearly identical functions
-//	@asyncsignalsafe
-ffs:	.leafprologue
-	.profilable
-	or	$-1,%edx
-	bsf	%edi,%eax
-	cmovz	%edx,%eax
-	inc	%eax
-	.leafepilogue
-	.endfn	ffs,globl

libc/nexgen32e/ffs.h

@@ -3,20 +3,6 @@
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-/*
- * BIT SCANNING 101
- *                          ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
- *      uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
- *    0x00000000      wut       32        0      wut       32
- *    0x00000001        0        0        1        0       31
- *    0x80000001        0        0        1       31        0
- *    0x80000000       31       31       32       31        0
- *    0x00000010        4        4        5        4       27
- *    0x08000010        4        4        5       27        4
- *    0x08000000       27       27       28       27        4
- *    0xffffffff        0        0        1       31        0
- */
-
 int ffs(int) pureconst;
 int ffsl(long) pureconst;
 int ffsll(long long) pureconst;

libc/nexgen32e/ffsl.S

@@ -1,45 +0,0 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 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/macros.internal.h"
-
-//	Finds lowest set bit in word.
-//
-//	      uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
-//	    0x00000000      wut       32        0      wut       32
-//	    0x00000001        0        0        1        0       31
-//	    0x80000001        0        0        1       31        0
-//	    0x80000000       31       31       32       31        0
-//	    0x00000010        4        4        5        4       27
-//	    0x08000010        4        4        5       27        4
-//	    0x08000000       27       27       28       27        4
-//	    0xffffffff        0        0        1       31        0
-//
-//	@param	rdi is the input number
-//	@return	number in range [1,64] or 0 if no bits set
-//	@see	also treasure trove of nearly identical functions
-//	@asyncsignalsafe
-ffsl:	.leafprologue
-	.profilable
-	or	$-1,%edx
-	bsf	%rdi,%rax
-	cmovz	%edx,%eax
-	inc	%eax
-	.leafepilogue
-	.endfn	ffsl,globl
-	.alias	ffsl,ffsll