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authorJoseph Myers <joseph@codesourcery.com>2018-03-20 00:34:52 +0000
committerJoseph Myers <joseph@codesourcery.com>2018-03-20 00:34:52 +0000
commit8d3f9e85cfa14e5f82a0e9e934b9fe1e4cb342bf (patch)
treeccddc18ea0339991b035ced7e3d437516b7abca1 /sysdeps/i386
parentd473f01520af910fbc7d61ed8504a8a35a1aa720 (diff)
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Add narrowing subtract functions.
This patch adds the narrowing subtract functions from TS 18661-1 to glibc's libm: fsub, fsubl, dsubl, f32subf64, f32subf32x, f32xsubf64 for all configurations; f32subf64x, f32subf128, f64subf64x, f64subf128, f32xsubf64x, f32xsubf128, f64xsubf128 for configurations with _Float64x and _Float128; __nldbl_dsubl for ldbl-opt. The changes are essentially the same as for the narrowing add functions, so the description of those generally applies to this patch as well. Tested for x86_64, x86, mips64 (all three ABIs, both hard and soft float) and powerpc, and with build-many-glibcs.py. * math/Makefile (libm-narrow-fns): Add sub. (libm-test-funcs-narrow): Likewise. * math/Versions (GLIBC_2.28): Add narrowing subtract functions. * math/bits/mathcalls-narrow.h (sub): Use __MATHCALL_NARROW. * math/gen-auto-libm-tests.c (test_functions): Add sub. * math/math-narrow.h (CHECK_NARROW_SUB): New macro. (NARROW_SUB_ROUND_TO_ODD): Likewise. (NARROW_SUB_TRIVIAL): Likewise. * sysdeps/ieee754/float128/float128_private.h (__fsubl): New macro. (__dsubl): Likewise. * sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fsub and dsub. (CFLAGS-nldbl-dsub.c): New variable. (CFLAGS-nldbl-fsub.c): Likewise. * sysdeps/ieee754/ldbl-opt/Versions (GLIBC_2.28): Add __nldbl_dsubl. * sysdeps/ieee754/ldbl-opt/nldbl-compat.h (__nldbl_dsubl): New prototype. * manual/arith.texi (Misc FP Arithmetic): Document fsub, fsubl, dsubl, fMsubfN, fMsubfNx, fMxsubfN and fMxsubfNx. * math/auto-libm-test-in: Add tests of sub. * math/auto-libm-test-out-narrow-sub: New generated file. * math/libm-test-narrow-sub.inc: New file. * sysdeps/i386/fpu/s_f32xsubf64.c: Likewise. * sysdeps/ieee754/dbl-64/s_f32xsubf64.c: Likewise. * sysdeps/ieee754/dbl-64/s_fsub.c: Likewise. * sysdeps/ieee754/float128/s_f32subf128.c: Likewise. * sysdeps/ieee754/float128/s_f64subf128.c: Likewise. * sysdeps/ieee754/float128/s_f64xsubf128.c: Likewise. * sysdeps/ieee754/ldbl-128/s_dsubl.c: Likewise. * sysdeps/ieee754/ldbl-128/s_f64xsubf128.c: Likewise. * sysdeps/ieee754/ldbl-128/s_fsubl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_dsubl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_fsubl.c: Likewise. * sysdeps/ieee754/ldbl-96/s_dsubl.c: Likewise. * sysdeps/ieee754/ldbl-96/s_fsubl.c: Likewise. * sysdeps/ieee754/ldbl-opt/nldbl-dsub.c: Likewise. * sysdeps/ieee754/ldbl-opt/nldbl-fsub.c: Likewise. * sysdeps/ieee754/soft-fp/s_dsubl.c: Likewise. * sysdeps/ieee754/soft-fp/s_fsub.c: Likewise. * sysdeps/ieee754/soft-fp/s_fsubl.c: Likewise. * sysdeps/powerpc/fpu/libm-test-ulps: Update. * sysdeps/mach/hurd/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
Diffstat (limited to 'sysdeps/i386')
-rw-r--r--sysdeps/i386/fpu/s_f32xsubf64.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/s_f32xsubf64.c b/sysdeps/i386/fpu/s_f32xsubf64.c
new file mode 100644
index 0000000..3a7dbca
--- /dev/null
+++ b/sysdeps/i386/fpu/s_f32xsubf64.c
@@ -0,0 +1,41 @@
+/* Subtract _Float64 values, converting the result to _Float32x. i386 version.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <math.h>
+#include <fpu_control.h>
+#include <math_private.h>
+#include <math-narrow.h>
+
+_Float32x
+__f32xsubf64 (_Float64 x, _Float64 y)
+{
+ /* To avoid double rounding, set double precision for the subtraction.
+ math_narrow_eval is still needed to eliminate excess range in the
+ case of overflow. If the result of the subtraction is in the
+ subnormal range for double, it is exact, so no issues of double
+ rounding for subnormals arise. */
+ fpu_control_t cw, cw_double;
+ _FPU_GETCW (cw);
+ cw_double = (cw & ~_FPU_EXTENDED) | _FPU_DOUBLE;
+ _FPU_SETCW (cw_double);
+ _Float32x ret = math_narrow_eval (x - y);
+ _FPU_SETCW (cw);
+ CHECK_NARROW_SUB (ret, x, y);
+ return ret;
+}
+libm_alias_float32x_float64 (sub)