libc: implement common abs for various integer sizes (#23893)

* libc: implement common `abs` for various integer sizes

* libc: move imaxabs to inttypes.zig and don't use cInclude

* libc: delete `fabs` c implementations because already implemented in compiler_rt

* libc: export functions depending on the target libc

Previously all the functions that were exported were handled equally,
though some may exist and some not inside the same file. Moving the
checks inside the file allows handling different functions differently

* remove empty ifs in inttypes

Co-authored-by: Alex Rønne Petersen <alex@alexrp.com>

* remove empty ifs in stdlib

Co-authored-by: Alex Rønne Petersen <alex@alexrp.com>

* libc: use `@abs` for the absolute value calculation

---------

Co-authored-by: Alex Rønne Petersen <alex@alexrp.com>

lib/libc/mingw/math/fabsf.c

@@ -1,18 +0,0 @@
-/**
- * This file has no copyright assigned and is placed in the Public Domain.
- * This file is part of the mingw-w64 runtime package.
- * No warranty is given; refer to the file DISCLAIMER.PD within this package.
- */
-float fabsf (float x);
-
-float
-fabsf (float x)
-{
-#if defined(__x86_64__) || defined(_AMD64_) || defined(__arm__) || defined(_ARM_) || defined(__aarch64__) || defined(_ARM64_)
-  return __builtin_fabsf (x);
-#elif defined(__i386__) || defined(_X86_)
-  float res = 0.0F;
-  asm volatile ("fabs;" : "=t" (res) : "0" (x));
-  return res;
-#endif /* defined(__x86_64__) || defined(_AMD64_) || defined(__arm__) || defined(_ARM_) || defined(__aarch64__) || defined(_ARM64_) */
-}

lib/libc/mingw/math/fabsl.c

@@ -1,18 +0,0 @@
-/**
- * This file has no copyright assigned and is placed in the Public Domain.
- * This file is part of the mingw-w64 runtime package.
- * No warranty is given; refer to the file DISCLAIMER.PD within this package.
- */
-long double fabsl (long double x);
-
-long double
-fabsl (long double x)
-{
-#if defined(__x86_64__) || defined(_AMD64_) || defined(__i386__) || defined(_X86_)
-  long double res = 0.0L;
-  asm volatile ("fabs;" : "=t" (res) : "0" (x));
-  return res;
-#elif defined(__arm__) || defined(_ARM_) || defined(__aarch64__) || defined(_ARM64_)
-  return __builtin_fabsl (x);
-#endif /* defined(__x86_64__) || defined(_AMD64_) || defined(__i386__) || defined(_X86_) */
-}

lib/libc/musl/src/math/aarch64/fabs.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-double fabs(double x)
-{
-	__asm__ ("fabs %d0, %d1" : "=w"(x) : "w"(x));
-	return x;
-}

lib/libc/musl/src/math/aarch64/fabsf.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-float fabsf(float x)
-{
-	__asm__ ("fabs %s0, %s1" : "=w"(x) : "w"(x));
-	return x;
-}

lib/libc/musl/src/math/arm/fabs.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __ARM_PCS_VFP && __ARM_FP&8
-
-double fabs(double x)
-{
-	__asm__ ("vabs.f64 %P0, %P1" : "=w"(x) : "w"(x));
-	return x;
-}
-
-#else
-
-#include "../fabs.c"
-
-#endif

lib/libc/musl/src/math/arm/fabsf.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __ARM_PCS_VFP && !BROKEN_VFP_ASM
-
-float fabsf(float x)
-{
-	__asm__ ("vabs.f32 %0, %1" : "=t"(x) : "t"(x));
-	return x;
-}
-
-#else
-
-#include "../fabsf.c"
-
-#endif

lib/libc/musl/src/math/fabs.c

@@ -1,9 +0,0 @@
-#include <math.h>
-#include <stdint.h>
-
-double fabs(double x)
-{
-	union {double f; uint64_t i;} u = {x};
-	u.i &= -1ULL/2;
-	return u.f;
-}

lib/libc/musl/src/math/fabsf.c

@@ -1,9 +0,0 @@
-#include <math.h>
-#include <stdint.h>
-
-float fabsf(float x)
-{
-	union {float f; uint32_t i;} u = {x};
-	u.i &= 0x7fffffff;
-	return u.f;
-}

lib/libc/musl/src/math/fabsl.c

@@ -1,15 +0,0 @@
-#include "libm.h"
-#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
-long double fabsl(long double x)
-{
-	return fabs(x);
-}
-#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
-long double fabsl(long double x)
-{
-	union ldshape u = {x};
-
-	u.i.se &= 0x7fff;
-	return u.f;
-}
-#endif

lib/libc/musl/src/math/i386/fabs.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-double fabs(double x)
-{
-	__asm__ ("fabs" : "+t"(x));
-	return x;
-}

lib/libc/musl/src/math/i386/fabsf.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-float fabsf(float x)
-{
-	__asm__ ("fabs" : "+t"(x));
-	return x;
-}

lib/libc/musl/src/math/i386/fabsl.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-long double fabsl(long double x)
-{
-	__asm__ ("fabs" : "+t"(x));
-	return x;
-}

lib/libc/musl/src/math/mips/fabs.c

@@ -1,16 +0,0 @@
-#if !defined(__mips_soft_float) && defined(__mips_abs2008)
-
-#include <math.h>
-
-double fabs(double x)
-{
-	double r;
-	__asm__("abs.d %0,%1" : "=f"(r) : "f"(x));
-	return r;
-}
-
-#else
-
-#include "../fabs.c"
-
-#endif

lib/libc/musl/src/math/mips/fabsf.c

@@ -1,16 +0,0 @@
-#if !defined(__mips_soft_float) && defined(__mips_abs2008)
-
-#include <math.h>
-
-float fabsf(float x)
-{
-	float r;
-	__asm__("abs.s %0,%1" : "=f"(r) : "f"(x));
-	return r;
-}
-
-#else
-
-#include "../fabsf.c"
-
-#endif

lib/libc/musl/src/math/powerpc/fabs.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if defined(_SOFT_FLOAT) || defined(__NO_FPRS__) || defined(BROKEN_PPC_D_ASM)
-
-#include "../fabs.c"
-
-#else
-
-double fabs(double x)
-{
-	__asm__ ("fabs %0, %1" : "=d"(x) : "d"(x));
-	return x;
-}
-
-#endif

lib/libc/musl/src/math/powerpc/fabsf.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if defined(_SOFT_FLOAT) || defined(__NO_FPRS__)
-
-#include "../fabsf.c"
-
-#else
-
-float fabsf(float x)
-{
-	__asm__ ("fabs %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#endif

lib/libc/musl/src/math/powerpc64/fabs.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-double fabs(double x)
-{
-	__asm__ ("fabs %0, %1" : "=d"(x) : "d"(x));
-	return x;
-}

lib/libc/musl/src/math/powerpc64/fabsf.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-float fabsf(float x)
-{
-	__asm__ ("fabs %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}

lib/libc/musl/src/math/riscv32/fabs.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __riscv_flen >= 64
-
-double fabs(double x)
-{
-	__asm__ ("fabs.d %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabs.c"
-
-#endif

lib/libc/musl/src/math/riscv32/fabsf.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __riscv_flen >= 32
-
-float fabsf(float x)
-{
-	__asm__ ("fabs.s %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabsf.c"
-
-#endif

lib/libc/musl/src/math/riscv64/fabs.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __riscv_flen >= 64
-
-double fabs(double x)
-{
-	__asm__ ("fabs.d %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabs.c"
-
-#endif

lib/libc/musl/src/math/riscv64/fabsf.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if __riscv_flen >= 32
-
-float fabsf(float x)
-{
-	__asm__ ("fabs.s %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabsf.c"
-
-#endif

lib/libc/musl/src/math/s390x/fabs.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if defined(__HTM__) || __ARCH__ >= 9
-
-double fabs(double x)
-{
-	__asm__ ("lpdbr %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabs.c"
-
-#endif

lib/libc/musl/src/math/s390x/fabsf.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if defined(__HTM__) || __ARCH__ >= 9
-
-float fabsf(float x)
-{
-	__asm__ ("lpebr %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabsf.c"
-
-#endif

lib/libc/musl/src/math/s390x/fabsl.c

@@ -1,15 +0,0 @@
-#include <math.h>
-
-#if defined(__HTM__) || __ARCH__ >= 9
-
-long double fabsl(long double x)
-{
-	__asm__ ("lpxbr %0, %1" : "=f"(x) : "f"(x));
-	return x;
-}
-
-#else
-
-#include "../fabsl.c"
-
-#endif

lib/libc/musl/src/math/x32/fabs.s

@@ -1,9 +0,0 @@
-.global fabs
-.type fabs,@function
-fabs:
-	xor %eax,%eax
-	dec %rax
-	shr %rax
-	movq %rax,%xmm1
-	andpd %xmm1,%xmm0
-	ret

lib/libc/musl/src/math/x32/fabsf.s

@@ -1,7 +0,0 @@
-.global fabsf
-.type fabsf,@function
-fabsf:
-	mov $0x7fffffff,%eax
-	movq %rax,%xmm1
-	andps %xmm1,%xmm0
-	ret

lib/libc/musl/src/math/x32/fabsl.s

@@ -1,6 +0,0 @@
-.global fabsl
-.type fabsl,@function
-fabsl:
-	fldt 8(%esp)
-	fabs
-	ret

lib/libc/musl/src/math/x86_64/fabs.c

@@ -1,10 +0,0 @@
-#include <math.h>
-
-double fabs(double x)
-{
-	double t;
-	__asm__ ("pcmpeqd %0, %0" : "=x"(t));          // t = ~0
-	__asm__ ("psrlq   $1, %0" : "+x"(t));          // t >>= 1
-	__asm__ ("andps   %1, %0" : "+x"(x) : "x"(t)); // x &= t
-	return x;
-}

lib/libc/musl/src/math/x86_64/fabsf.c

@@ -1,10 +0,0 @@
-#include <math.h>
-
-float fabsf(float x)
-{
-	float t;
-	__asm__ ("pcmpeqd %0, %0" : "=x"(t));          // t = ~0
-	__asm__ ("psrld   $1, %0" : "+x"(t));          // t >>= 1
-	__asm__ ("andps   %1, %0" : "+x"(x) : "x"(t)); // x &= t
-	return x;
-}

lib/libc/musl/src/math/x86_64/fabsl.c

@@ -1,7 +0,0 @@
-#include <math.h>
-
-long double fabsl(long double x)
-{
-	__asm__ ("fabs" : "+t"(x));
-	return x;
-}

lib/libc/musl/src/stdlib/abs.c

@@ -1,6 +0,0 @@
-#include <stdlib.h>
-
-int abs(int a)
-{
-	return a>0 ? a : -a;
-}

lib/libc/musl/src/stdlib/imaxabs.c

@@ -1,6 +0,0 @@
-#include <inttypes.h>
-
-intmax_t imaxabs(intmax_t a)
-{
-	return a>0 ? a : -a;
-}

lib/libc/musl/src/stdlib/labs.c

@@ -1,6 +0,0 @@
-#include <stdlib.h>
-
-long labs(long a)
-{
-	return a>0 ? a : -a;
-}

lib/libc/musl/src/stdlib/llabs.c

@@ -1,6 +0,0 @@
-#include <stdlib.h>
-
-long long llabs(long long a)
-{
-	return a>0 ? a : -a;
-}