[glibc] Use GCC builtins for ceil functions if desired.

[Stefan Liebler <stli@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=62560ee84095274bab1050817f42e782df226a17

commit 62560ee84095274bab1050817f42e782df226a17
Author: Stefan Liebler <stli@linux.ibm.com>
Date:   Wed Dec 11 15:09:21 2019 +0100

    Use GCC builtins for ceil functions if desired.
    
    This patch is using the corresponding GCC builtin for ceilf, ceil,
    ceill and ceilf128 if the USE_FUNCTION_BUILTIN macros are defined to one
    in math-use-builtins.h.
    
    This is the case for s390 if build with at least --march=z196 --mzarch.
    Otherwise the generic implementation is used.  The code of the generic
    implementation is not changed.
    
    Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/generic/math-use-builtins.h         |  5 +++++
 sysdeps/ieee754/dbl-64/s_ceil.c             |  6 ++++++
 sysdeps/ieee754/float128/float128_private.h |  3 +++
 sysdeps/ieee754/flt-32/s_ceilf.c            |  7 ++++++-
 sysdeps/ieee754/ldbl-128/s_ceill.c          |  6 ++++++
 sysdeps/s390/fpu/math-use-builtins.h        | 11 +++++++++++
 6 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
index e1c5df6..076ec66 100644
--- a/sysdeps/generic/math-use-builtins.h
+++ b/sysdeps/generic/math-use-builtins.h
@@ -36,4 +36,9 @@
 #define USE_FLOORL_BUILTIN 0
 #define USE_FLOORF128_BUILTIN 0
 
+#define USE_CEIL_BUILTIN 0
+#define USE_CEILF_BUILTIN 0
+#define USE_CEILL_BUILTIN 0
+#define USE_CEILF128_BUILTIN 0
+
 #endif /* math-use-builtins.h */
diff --git a/sysdeps/ieee754/dbl-64/s_ceil.c b/sysdeps/ieee754/dbl-64/s_ceil.c
index 8d66f02..3738211 100644
--- a/sysdeps/ieee754/dbl-64/s_ceil.c
+++ b/sysdeps/ieee754/dbl-64/s_ceil.c
@@ -21,10 +21,15 @@
 #include <math.h>
 #include <math_private.h>
 #include <libm-alias-double.h>
+#include <math-use-builtins.h>
 
 double
 __ceil (double x)
 {
+#if USE_CEIL_BUILTIN
+  return __builtin_ceil (x);
+#else
+  /* Use generic implementation.  */
   int64_t i0, i;
   int32_t j0;
   EXTRACT_WORDS64 (i0, x);
@@ -58,6 +63,7 @@ __ceil (double x)
     }
   INSERT_WORDS64 (x, i0);
   return x;
+#endif /* ! USE_CEIL_BUILTIN  */
 }
 #ifndef __ceil
 libm_alias_double (__ceil, ceil)
diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
index 8c8a74a..01881b5 100644
--- a/sysdeps/ieee754/float128/float128_private.h
+++ b/sysdeps/ieee754/float128/float128_private.h
@@ -146,6 +146,8 @@
 #define USE_RINTL_BUILTIN USE_RINTF128_BUILTIN
 #undef USE_FLOORL_BUILTIN
 #define USE_FLOORL_BUILTIN USE_FLOORF128_BUILTIN
+#undef USE_CEILL_BUILTIN
+#define USE_CEILL_BUILTIN USE_CEILF128_BUILTIN
 
 /* IEEE function renames.  */
 #define __ieee754_acoshl __ieee754_acoshf128
@@ -352,6 +354,7 @@
 #define __builtin_nearbyintl __builtin_nearbyintf128
 #define __builtin_rintl __builtin_rintf128
 #define __builtin_floorl __builtin_floorf128
+#define __builtin_ceill __builtin_ceilf128
 
 /* Get the constant suffix from bits/floatn-compat.h.  */
 #define L(x) __f128 (x)
diff --git a/sysdeps/ieee754/flt-32/s_ceilf.c b/sysdeps/ieee754/flt-32/s_ceilf.c
index 25cba08..7d4990f 100644
--- a/sysdeps/ieee754/flt-32/s_ceilf.c
+++ b/sysdeps/ieee754/flt-32/s_ceilf.c
@@ -17,11 +17,15 @@
 #include <math.h>
 #include <math_private.h>
 #include <libm-alias-float.h>
-
+#include <math-use-builtins.h>
 
 float
 __ceilf(float x)
 {
+#if USE_CEILF_BUILTIN
+  return __builtin_ceilf (x);
+#else
+  /* Use generic implementation.  */
 	int32_t i0,j0;
 	uint32_t i;
 
@@ -44,6 +48,7 @@ __ceilf(float x)
 	}
 	SET_FLOAT_WORD(x,i0);
 	return x;
+#endif /* ! USE_CEILF_BUILTIN  */
 }
 #ifndef __ceilf
 libm_alias_float (__ceil, ceil)
diff --git a/sysdeps/ieee754/ldbl-128/s_ceill.c b/sysdeps/ieee754/ldbl-128/s_ceill.c
index 2ec55de..02ffa7a 100644
--- a/sysdeps/ieee754/ldbl-128/s_ceill.c
+++ b/sysdeps/ieee754/ldbl-128/s_ceill.c
@@ -28,9 +28,14 @@ static char rcsid[] = "$NetBSD: $";
 #include <math.h>
 #include <math_private.h>
 #include <libm-alias-ldouble.h>
+#include <math-use-builtins.h>
 
 _Float128 __ceill(_Float128 x)
 {
+#if USE_CEILL_BUILTIN
+  return __builtin_ceill (x);
+#else
+  /* Use generic implementation.  */
 	int64_t i0,i1,j0;
 	uint64_t i,j;
 	GET_LDOUBLE_WORDS64(i0,i1,x);
@@ -64,5 +69,6 @@ _Float128 __ceill(_Float128 x)
 	}
 	SET_LDOUBLE_WORDS64(x,i0,i1);
 	return x;
+#endif /* ! USE_CEILL_BUILTIN  */
 }
 libm_alias_ldouble (__ceil, ceil)
diff --git a/sysdeps/s390/fpu/math-use-builtins.h b/sysdeps/s390/fpu/math-use-builtins.h
index c213c16..5435cbb 100644
--- a/sysdeps/s390/fpu/math-use-builtins.h
+++ b/sysdeps/s390/fpu/math-use-builtins.h
@@ -38,14 +38,20 @@
 # define USE_FLOORF_BUILTIN 1
 # define USE_FLOORL_BUILTIN 1
 
+# define USE_CEIL_BUILTIN 1
+# define USE_CEILF_BUILTIN 1
+# define USE_CEILL_BUILTIN 1
+
 # if __GNUC_PREREQ (8, 0)
 #  define USE_NEARBYINTF128_BUILTIN 1
 #  define USE_RINTF128_BUILTIN 1
 #  define USE_FLOORF128_BUILTIN 1
+#  define USE_CEILF128_BUILTIN 1
 # else
 #  define USE_NEARBYINTF128_BUILTIN 0
 #  define USE_RINTF128_BUILTIN 0
 #  define USE_FLOORF128_BUILTIN 0
+#  define USE_CEILF128_BUILTIN 0
 # endif
 
 #else
@@ -66,6 +72,11 @@
 # define USE_FLOORL_BUILTIN 0
 # define USE_FLOORF128_BUILTIN 0
 
+# define USE_CEIL_BUILTIN 0
+# define USE_CEILF_BUILTIN 0
+# define USE_CEILL_BUILTIN 0
+# define USE_CEILF128_BUILTIN 0
+
 #endif /* ! HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT  */
 
 #endif /* math-use-builtins.h */