Hi, On Cygwin AArch64, long double has the same representation and precision as double (64-bit), unlike x86 extended precision.
This patch updates math functions to correctly handle this case by avoiding
assumptions about extended precision in nextafterl and related functions.
It also updates rintl to use the generic implementation on AArch64 and
adjusts constants in cephes_mconf.h and lgammal.c accordingly.
Thanks & regards
Thiru
In-lined patch:
---
winsup/cygwin/math/cephes_mconf.h | 4 ++--
winsup/cygwin/math/lgammal.c | 4 ++--
winsup/cygwin/math/nextafterl.c | 4 ++++
winsup/cygwin/math/rintl.c | 2 +-
4 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/winsup/cygwin/math/cephes_mconf.h
b/winsup/cygwin/math/cephes_mconf.h
index 832fae0df..654de88bf 100644
--- a/winsup/cygwin/math/cephes_mconf.h
+++ b/winsup/cygwin/math/cephes_mconf.h
@@ -66,7 +66,7 @@ extern double __QNAN;
#endif
/*long double*/
-#if defined(__arm__) || defined(_ARM_)
+#if defined(__arm__) || defined(_ARM_) || defined(__aarch64__)
#define MAXNUML 1.7976931348623158E308
#define MAXLOGL 7.09782712893383996843E2
#define MINLOGL -7.08396418532264106224E2
@@ -84,7 +84,7 @@ extern double __QNAN;
#define PIL 3.1415926535897932384626L
#define PIO2L 1.5707963267948966192313L
#define PIO4L 7.8539816339744830961566E-1L
-#endif /* defined(__arm__) || defined(_ARM_) */
+#endif /* defined(__arm__) || defined(_ARM_) || defined(__aarch64__) */
#define isfinitel isfinite
#define isinfl isinf
diff --git a/winsup/cygwin/math/lgammal.c b/winsup/cygwin/math/lgammal.c
index 022a16acf..961eec280 100644
--- a/winsup/cygwin/math/lgammal.c
+++ b/winsup/cygwin/math/lgammal.c
@@ -198,11 +198,11 @@ static uLD C[] = {
/* log( sqrt( 2*pi ) ) */
static const long double LS2PI = 0.91893853320467274178L;
-#if defined(__arm__) || defined(_ARM_)
+#if defined(__arm__) || defined(_ARM_) || defined(__aarch64__)
#define MAXLGM 2.035093e36
#else
#define MAXLGM 1.04848146839019521116e+4928L
-#endif /* defined(__arm__) || defined(_ARM_) */
+#endif /* defined(__arm__) || defined(_ARM_) || defined(__aarch64__) */
/* Logarithm of gamma function */
/* Reentrant version */
diff --git a/winsup/cygwin/math/nextafterl.c b/winsup/cygwin/math/nextafterl.c
index b1e479a95..80c9c3c4d 100644
--- a/winsup/cygwin/math/nextafterl.c
+++ b/winsup/cygwin/math/nextafterl.c
@@ -16,6 +16,9 @@
long double
nextafterl (long double x, long double y)
{
+#if defined(__aarch64__) && (LDBL_MANT_DIG == DBL_MANT_DIG)
+ return (long double) nexttoward (x, y);
+# else
union {
long double ld;
struct {
@@ -63,6 +66,7 @@ nextafterl (long double x, long double y)
u.parts.mantissa |= normal_bit;
return u.ld;
+# endif /* defined(__aarch64__) */
}
/* nexttowardl is the same function with a different name. */
diff --git a/winsup/cygwin/math/rintl.c b/winsup/cygwin/math/rintl.c
index 9ec159d17..1e30de069 100644
--- a/winsup/cygwin/math/rintl.c
+++ b/winsup/cygwin/math/rintl.c
@@ -9,7 +9,7 @@ long double rintl (long double x) {
long double retval = 0.0L;
#if defined(_AMD64_) || defined(__x86_64__) || defined(_X86_) ||
defined(__i386__)
__asm__ __volatile__ ("frndint;": "=t" (retval) : "0" (x));
-#elif defined(__arm__) || defined(_ARM_)
+#elif defined(__arm__) || defined(_ARM_)|| defined(__aarch64__)
retval = rint(x);
#endif
return retval;
--
Cygwin-Adapt-math-functions-to-use-64bit-long-double.patch
Description: Cygwin-Adapt-math-functions-to-use-64bit-long-double.patch
