Make improvements

- More timspec_*() and timeval_*() APIs have been introduced.
- The copyfd() function is now simplified thanks to POSIX rules.
- More Cosmo-specific APIs have been moved behind the COSMO define.
- The setitimer() polyfill for Windows NT is now much higher quality.
- Fixed build error for MODE=aarch64 due to -mstringop-strategy=loop.
- This change introduces `make MODE=nox87 toolchain` which makes it
  possible to build programs using your cosmocc toolchain that don't
  have legacy fpu instructions. This is useful, for example, if you
  want to have a ~22kb tinier blink virtual machine.

third_party/compiler_rt/addtf3.c

@@ -12,6 +12,8 @@
 // default rounding (to nearest, ties to even).
 //
 //===----------------------------------------------------------------------===//
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -26,3 +28,5 @@ COMPILER_RT_ABI long double __addtf3(long double a, long double b){
 }
 
 #endif
+
+#endif /* long double is long */

third_party/compiler_rt/divtc3.c

@@ -12,6 +12,8 @@
  *
  *===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -64,3 +66,5 @@ __divtc3(long double __a, long double __b, long double __c, long double __d)
     }
     return z;
 }
+
+#endif /* long double is long */

third_party/compiler_rt/divxc3.c

@@ -11,6 +11,8 @@
  * This file implements __divxc3 for the compiler_rt library.
  *
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -64,3 +66,5 @@ __divxc3(long double __a, long double __b, long double __c, long double __d)
 }
 
 #endif
+
+#endif /* long double is long */

third_party/compiler_rt/fixunsxfdi.c

@@ -12,6 +12,8 @@
  *
  * ===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -47,3 +49,5 @@ __fixunsxfdi(long double a)
 }
 
 #endif
+
+#endif /* long double is long */

third_party/compiler_rt/fixunsxfsi.c

@@ -12,6 +12,8 @@
  *
  * ===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -46,3 +48,5 @@ __fixunsxfsi(long double a)
 }
 
 #endif /* !_ARCH_PPC */
+
+#endif /* long double is long */

third_party/compiler_rt/fixunsxfti.c

@@ -12,6 +12,8 @@
  *
  * ===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -51,3 +53,5 @@ __fixunsxfti(long double a)
 }
 
 #endif /* CRT_HAS_128BIT */
+
+#endif /* long double is long */

third_party/compiler_rt/fixxfdi.c

@@ -12,6 +12,8 @@
  *
  * ===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -49,3 +51,5 @@ __fixxfdi(long double a)
 }
 
 #endif /* !_ARCH_PPC */
+
+#endif /* long double is long */

third_party/compiler_rt/fixxfti.c

@@ -12,6 +12,8 @@
  *
  * ===----------------------------------------------------------------------===
  */
+#include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 STATIC_YOINK("huge_compiler_rt_license");
 
@@ -52,3 +54,5 @@ __fixxfti(long double a)
 }
 
 #endif /* CRT_HAS_128BIT */
+
+#endif /* long double is long */

third_party/compiler_rt/ilogbl.c

@@ -29,22 +29,21 @@
 #include "libc/math.h"
 #include "libc/tinymath/internal.h"
 #include "libc/tinymath/ldshape.internal.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
 Copyright 2005-2014 Rich Felker, et. al.\"");
 asm(".include \"libc/disclaimer.inc\"");
-/* clang-format off */
+// clang-format off
 
-#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+/**
+ * Returns log₂𝑥 exponent part of double.
+ */
 int ilogbl(long double x)
 {
-	return ilogb(x);
-}
-#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
-int ilogbl(long double x)
-{
-	//#pragma STDC FENV_ACCESS ON
+#if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
+// #pragma STDC FENV_ACCESS ON
 	union ldshape u = {x};
 	uint64_t m = u.i.m;
 	int e = u.i.se & 0x7fff;
@@ -63,11 +62,8 @@ int ilogbl(long double x)
 		return m<<1 ? FP_ILOGBNAN : INT_MAX;
 	}
 	return e - 0x3fff;
-}
 #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
-int ilogbl(long double x)
-{
-	//#pragma STDC FENV_ACCESS ON
+// #pragma STDC FENV_ACCESS ON
 	union ldshape u = {x};
 	int e = u.i.se & 0x7fff;
 
@@ -86,5 +82,7 @@ int ilogbl(long double x)
 		return u.f ? FP_ILOGBNAN : INT_MAX;
 	}
 	return e - 0x3fff;
-}
 #endif
+}
+
+#endif /* long double is long */

third_party/compiler_rt/logbl.c

@@ -26,19 +26,14 @@
 │                                                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/math.h"
+#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
 
 asm(".ident\t\"\\n\\n\
 Musl libc (MIT License)\\n\
 Copyright 2005-2014 Rich Felker, et. al.\"");
 asm(".include \"libc/disclaimer.inc\"");
-/* clang-format off */
+// clang-format off
 
-#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
-long double logbl(long double x)
-{
-	return logb(x);
-}
-#else
 long double logbl(long double x)
 {
 	if (!isfinite(x))
@@ -47,4 +42,5 @@ long double logbl(long double x)
 		return -1/(x*x);
 	return ilogbl(x);
 }
-#endif
+
+#endif /* long double is long */