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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2013-11-25 06:12:30 -0600
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2013-11-25 06:34:41 -0600
commit41e8926aa4b7f17bc95984737ee82a254ad0911c (patch)
treef113bbedd0ec991ae1b9dddf3a36077e22d19815
parent085b5ddfe301eb74bc9f824ff293f054c1c910b7 (diff)
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PowerPC: Set/restore rounding mode only when needed
This patch helps some math functions performance by adding the libc_fexxx variant of inline functions to handle both FPU round and exception set/restore and by using them on the libc_fexxx_ctx functions. It is based on already coded fexxx family functions for PPC with fpu. Here is the summary of performance improvements due this patch (measured on a POWER7 machine): Before: cos(): ITERS:9.5895e+07: TOTAL:5116.03Mcy, MAX:77.6cy, MIN:49.792cy, 18744 calls/Mcy exp(): ITERS:2.827e+07: TOTAL:5187.15Mcy, MAX:494.018cy, MIN:38.422cy, 5450.01 calls/Mcy pow(): ITERS:6.1705e+07: TOTAL:5144.26Mcy, MAX:171.95cy, MIN:29.935cy, 11994.9 calls/Mcy sin(): ITERS:8.6898e+07: TOTAL:5117.06Mcy, MAX:83.841cy, MIN:46.582cy, 16982 calls/Mcy tan(): ITERS:2.9473e+07: TOTAL:5115.39Mcy, MAX:191.017cy, MIN:172.352cy, 5761.63 calls/Mcy After: cos(): ITERS:2.05265e+08: TOTAL:5111.37Mcy, MAX:78.754cy, MIN:24.196cy, 40158.5 calls/Mcy exp(): ITERS:3.341e+07: TOTAL:5170.84Mcy, MAX:476.317cy, MIN:15.574cy, 6461.23 calls/Mcy pow(): ITERS:7.6153e+07: TOTAL:5129.1Mcy, MAX:147.5cy, MIN:30.916cy, 14847.2 calls/Mcy sin(): ITERS:1.58816e+08: TOTAL:5115.11Mcy, MAX:1490.39cy, MIN:22.341cy, 31048.4 calls/Mcy tan(): ITERS:3.4964e+07: TOTAL:5114.18Mcy, MAX:177.422cy, MIN:146.115cy, 6836.68 calls/Mcy
-rw-r--r--ChangeLog16
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/e_expl.c31
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_llrintl.c2
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_lrintl.c2
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_rintl.c2
-rw-r--r--sysdeps/powerpc/fpu/fenv_libc.h6
-rw-r--r--sysdeps/powerpc/fpu/fenv_private.h274
-rw-r--r--sysdeps/powerpc/fpu/math_private.h1
8 files changed, 309 insertions, 25 deletions
diff --git a/ChangeLog b/ChangeLog
index b9201fc..9e2a0c6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2013-11-25 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+
+ * sysdeps/ieee754/ldbl-128ibm/e_expl.c (__ieee754_expl): Use
+ SET_RESTORE_ROUND instead of feholdexcept/fesetround/fesetenv.
+ * sysdeps/powerpc/fpu/fenv_libc.h (__fegetround): Remove define.
+ (__fesetround): Remove define.
+ * sysdeps/powerpc/fpu/fenv_private.h: New file: Inline floating point
+ rounding and exceptions handling.
+ * sysdeps/powerpc/fpu/math_private.h: Include fenv_private.h.
+ * sysdeps/powerpc/fpu/fenv_libc.h (__fe_mask_env): Define as hidden.
+ (__fe_nomask_env): Likewise.
+ * sysdeps/ieee754/ldbl-128ibm/s_llrintl.c (__llrintl): Use
+ __fegetround instead of fegetround.
+ * sysdeps/ieee754/ldbl-128ibm/s_lrintl.c (__lrintl): Likewise.
+ * sysdeps/ieee754/ldbl-128ibm/s_rintl.c (__rintl): Likewise.
+
2013-11-21 Roland McGrath <roland@hack.frob.com>
* malloc/malloc.c: Move #include <sys/param.h> to the top; comment why
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_expl.c b/sysdeps/ieee754/ldbl-128ibm/e_expl.c
index f7c50bf..65ef185 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_expl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_expl.c
@@ -134,18 +134,17 @@ static const long double C[] = {
long double
__ieee754_expl (long double x)
{
+ long double result, x22;
+ union ibm_extended_long_double ex2_u, scale_u;
+ int unsafe;
+
/* Check for usual case. */
if (isless (x, himark) && isgreater (x, lomark))
{
- int tval1, tval2, unsafe, n_i, exponent2;
- long double x22, n, result, xl;
- union ibm_extended_long_double ex2_u, scale_u;
- fenv_t oldenv;
-
- feholdexcept (&oldenv);
-#ifdef FE_TONEAREST
- fesetround (FE_TONEAREST);
-#endif
+ int tval1, tval2, n_i, exponent2;
+ long double n, xl;
+
+ SET_RESTORE_ROUND (FE_TONEAREST);
n = __roundl (x*M_1_LN2);
x = x-n*M_LN2_0;
@@ -201,11 +200,6 @@ __ieee754_expl (long double x)
less than 4.8e-39. */
x22 = x + x*x*(P1+x*(P2+x*(P3+x*(P4+x*(P5+x*P6)))));
- /* Return result. */
- fesetenv (&oldenv);
-
- result = x22 * ex2_u.ld + ex2_u.ld;
-
/* Now we can test whether the result is ultimate or if we are unsure.
In the later case we should probably call a mpn based routine to give
the ultimate result.
@@ -235,10 +229,6 @@ __ieee754_expl (long double x)
return __ieee754_expl_proc2 (origx);
}
*/
- if (!unsafe)
- return result;
- else
- return result * scale_u.ld;
}
/* Exceptional cases: */
else if (isless (x, himark))
@@ -253,5 +243,10 @@ __ieee754_expl (long double x)
else
/* Return x, if x is a NaN or Inf; or overflow, otherwise. */
return TWO1023*x;
+
+ result = x22 * ex2_u.ld + ex2_u.ld;
+ if (!unsafe)
+ return result;
+ return result * scale_u.ld;
}
strong_alias (__ieee754_expl, __expl_finite)
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
index 8560349..3503973 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
@@ -43,7 +43,7 @@ __llrintl (long double x)
#endif
)
{
- save_round = fegetround ();
+ save_round = __fegetround ();
if (__builtin_expect ((xh == -(double) (-__LONG_LONG_MAX__ - 1)), 0))
{
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c b/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c
index 588098d..49dbd42 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c
@@ -49,7 +49,7 @@ __lrintl (long double x)
#endif
)
{
- save_round = fegetround ();
+ save_round = __fegetround ();
#if __LONG_MAX__ == 2147483647
long long llhi = (long long) xh;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_rintl.c b/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
index 48dbe85..5fd6bb8 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_rintl.c
@@ -40,7 +40,7 @@ __rintl (long double x)
__builtin_inf ()), 1))
{
double orig_xh;
- int save_round = fegetround ();
+ int save_round = __fegetround ();
/* Long double arithmetic, including the canonicalisation below,
only works in round-to-nearest mode. */
diff --git a/sysdeps/powerpc/fpu/fenv_libc.h b/sysdeps/powerpc/fpu/fenv_libc.h
index cb15c1c..ecd6b91 100644
--- a/sysdeps/powerpc/fpu/fenv_libc.h
+++ b/sysdeps/powerpc/fpu/fenv_libc.h
@@ -23,9 +23,9 @@
#include <ldsodefs.h>
#include <sysdep.h>
-extern const fenv_t *__fe_nomask_env (void);
+extern const fenv_t *__fe_nomask_env (void) attribute_hidden;
-extern const fenv_t *__fe_mask_env (void);
+extern const fenv_t *__fe_mask_env (void) attribute_hidden;
/* The sticky bits in the FPSCR indicating exceptions have occurred. */
#define FPSCR_STICKY_BITS ((FE_ALL_EXCEPT | FE_ALL_INVALID) & ~FE_INVALID)
@@ -83,7 +83,6 @@ __fegetround (void)
"mfcr %0" : "=r"(result) : : "cr7");
return result & 3;
}
-#define fegetround() __fegetround()
static inline int
__fesetround (int round)
@@ -107,7 +106,6 @@ __fesetround (int round)
return 0;
}
-#define fesetround(mode) __fesetround(mode)
/* Definitions of all the FPSCR bit numbers */
enum {
diff --git a/sysdeps/powerpc/fpu/fenv_private.h b/sysdeps/powerpc/fpu/fenv_private.h
new file mode 100644
index 0000000..293f840
--- /dev/null
+++ b/sysdeps/powerpc/fpu/fenv_private.h
@@ -0,0 +1,274 @@
+/* Private floating point rounding and exceptions handling. PowerPC version.
+ Copyright (C) 2013 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/>. */
+
+#ifndef FENV_PRIVATE_H
+#define FENV_PRIVATE_H 1
+
+#include <fenv.h>
+#include <fenv_libc.h>
+#include <fpu_control.h>
+
+#define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM \
+ | _FPU_MASK_XM | _FPU_MASK_IM)
+
+/* Mask everything but the rounding moded and non-IEEE arithmetic flags. */
+#define _FPU_MASK_ROUNDING 0xffffffff00000007LL
+
+/* Mask restore rounding mode and exception enabled. */
+#define _FPU_MASK_EXCEPT_ROUND 0xffffffff1fffff00LL
+
+/* Mask exception enable but fraction rounded/inexact and FP result/CC
+ bits. */
+#define _FPU_MASK_FRAC_INEX_RET_CC 0x1ff80fff
+
+static __always_inline void
+libc_feholdexcept_ppc (fenv_t *envp)
+{
+ fenv_union_t old, new;
+
+ old.fenv = *envp = fegetenv_register ();
+
+ new.l = old.l & _FPU_MASK_ROUNDING;
+
+ /* If the old env had any enabled exceptions, then mask SIGFPE in the
+ MSR FE0/FE1 bits. This may allow the FPU to run faster because it
+ always takes the default action and can not generate SIGFPE. */
+ if ((old.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_mask_env ();
+
+ fesetenv_register (new.fenv);
+}
+
+static __always_inline void
+libc_fesetround_ppc (int r)
+{
+ __fesetround (r);
+}
+
+static __always_inline void
+libc_feholdexcept_setround_ppc (fenv_t *envp, int r)
+{
+ fenv_union_t old, new;
+
+ old.fenv = *envp = fegetenv_register ();
+
+ new.l = (old.l & _FPU_MASK_ROUNDING) | r;
+
+ if ((old.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_mask_env ();
+
+ fesetenv_register (new.fenv);
+}
+
+static __always_inline int
+libc_fetestexcept_ppc (int e)
+{
+ fenv_union_t u;
+ u.fenv = fegetenv_register ();
+ return u.l & e;
+}
+
+static __always_inline void
+libc_fesetenv_ppc (const fenv_t *envp)
+{
+ fenv_union_t old, new;
+
+ new.fenv = *envp;
+ old.fenv = fegetenv_register ();
+
+ /* If the old env has no enabled exceptions and the new env has any enabled
+ exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits. This will put the
+ hardware into "precise mode" and may cause the FPU to run slower on some
+ hardware. */
+ if ((old.l & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_nomask_env ();
+
+ /* If the old env had any enabled exceptions and the new env has no enabled
+ exceptions, then mask SIGFPE in the MSR FE0/FE1 bits. This may allow the
+ FPU to run faster because it always takes the default action and can not
+ generate SIGFPE. */
+ if ((old.l & _FPU_MASK_ALL) != 0 && (new.l & _FPU_MASK_ALL) == 0)
+ (void) __fe_mask_env ();
+
+ fesetenv_register (*envp);
+}
+
+static __always_inline int
+libc_feupdateenv_test_ppc (fenv_t *envp, int ex)
+{
+ fenv_union_t old, new;
+
+ new.fenv = *envp;
+ old.fenv = fegetenv_register ();
+
+ /* Restore rounding mode and exception enable from *envp and merge
+ exceptions. Leave fraction rounded/inexact and FP result/CC bits
+ unchanged. */
+ new.l = (old.l & _FPU_MASK_EXCEPT_ROUND)
+ | (new.l & _FPU_MASK_FRAC_INEX_RET_CC);
+
+ if ((old.l & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_nomask_env ();
+
+ if ((old.l & _FPU_MASK_ALL) != 0 && (new.l & _FPU_MASK_ALL) == 0)
+ (void) __fe_mask_env ();
+
+ fesetenv_register (new.fenv);
+
+ return old.l & ex;
+}
+
+static __always_inline void
+libc_feupdateenv_ppc (fenv_t *e)
+{
+ libc_feupdateenv_test_ppc (e, 0);
+}
+
+static __always_inline void
+libc_feholdsetround_ppc (fenv_t *e, int r)
+{
+ fenv_union_t old, new;
+
+ old.fenv = fegetenv_register ();
+ /* Clear current precision and set newer one. */
+ new.l = (old.l & ~0x3) | r;
+ *e = old.fenv;
+
+ if ((old.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_mask_env ();
+ fesetenv_register (new.fenv);
+}
+
+static __always_inline void
+libc_feresetround_ppc (fenv_t *envp)
+{
+ fenv_union_t old, new;
+
+ new.fenv = *envp;
+ old.fenv = fegetenv_register ();
+
+ /* Restore rounding mode and exception enable from *envp and merge
+ exceptions. Leave fraction rounded/inexact and FP result/CC bits
+ unchanged. */
+ new.l = (old.l & _FPU_MASK_EXCEPT_ROUND)
+ | (new.l & _FPU_MASK_FRAC_INEX_RET_CC);
+
+ if ((old.l & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_nomask_env ();
+
+ if ((old.l & _FPU_MASK_ALL) != 0 && (new.l & _FPU_MASK_ALL) == 0)
+ (void) __fe_mask_env ();
+
+ /* Atomically enable and raise (if appropriate) exceptions set in `new'. */
+ fesetenv_register (new.fenv);
+}
+
+#define libc_feholdexceptf libc_feholdexcept_ppc
+#define libc_feholdexcept libc_feholdexcept_ppc
+#define libc_feholdexcept_setroundf libc_feholdexcept_setround_ppc
+#define libc_feholdexcept_setround libc_feholdexcept_setround_ppc
+#define libc_fetestexceptf libc_fetestexcept_ppc
+#define libc_fetestexcept libc_fetestexcept_ppc
+#define libc_fesetroundf libc_fesetround_ppc
+#define libc_fesetround libc_fesetround_ppc
+#define libc_fesetenvf libc_fesetenv_ppc
+#define libc_fesetenv libc_fesetenv_ppc
+#define libc_feupdateenv_testf libc_feupdateenv_test_ppc
+#define libc_feupdateenv_test libc_feupdateenv_test_ppc
+#define libc_feupdateenvf libc_feupdateenv_ppc
+#define libc_feupdateenv libc_feupdateenv_ppc
+#define libc_feholdsetroundf libc_feholdsetround_ppc
+#define libc_feholdsetround libc_feholdsetround_ppc
+#define libc_feresetroundf libc_feresetround_ppc
+#define libc_feresetround libc_feresetround_ppc
+
+
+/* We have support for rounding mode context. */
+#define HAVE_RM_CTX 1
+
+static __always_inline void
+libc_feholdexcept_setround_ppc_ctx (struct rm_ctx *ctx, int r)
+{
+ fenv_union_t old, new;
+
+ old.fenv = fegetenv_register ();
+
+ new.l = (old.l & _FPU_MASK_ROUNDING) | r;
+ ctx->env = old.fenv;
+ if (__glibc_unlikely (new.l != old.l))
+ {
+ if ((old.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_mask_env ();
+ fesetenv_register (new.fenv);
+ ctx->updated_status = true;
+ }
+ else
+ ctx->updated_status = false;
+}
+
+static __always_inline void
+libc_fesetenv_ppc_ctx (struct rm_ctx *ctx)
+{
+ libc_fesetenv_ppc (&ctx->env);
+}
+
+static __always_inline void
+libc_feupdateenv_ppc_ctx (struct rm_ctx *ctx)
+{
+ if (__glibc_unlikely (ctx->updated_status))
+ libc_feupdateenv_test_ppc (&ctx->env, 0);
+}
+
+static __always_inline void
+libc_feholdsetround_ppc_ctx (struct rm_ctx *ctx, int r)
+{
+ fenv_union_t old, new;
+
+ old.fenv = fegetenv_register ();
+ new.l = (old.l & ~0x3) | r;
+ ctx->env = old.fenv;
+ if (__glibc_unlikely (new.l != old.l))
+ {
+ if ((old.l & _FPU_MASK_ALL) != 0)
+ (void) __fe_mask_env ();
+ fesetenv_register (new.fenv);
+ ctx->updated_status = true;
+ }
+ else
+ ctx->updated_status = false;
+}
+
+static __always_inline void
+libc_feresetround_ppc_ctx (struct rm_ctx *ctx)
+{
+ if (__glibc_unlikely (ctx->updated_status))
+ libc_feresetround_ppc (&ctx->env);
+}
+
+#define libc_feholdexcept_setroundf_ctx libc_feholdexcept_setround_ppc_ctx
+#define libc_feholdexcept_setround_ctx libc_feholdexcept_setround_ppc_ctx
+#define libc_fesetenv_ctx libc_fesetenv_ppc_ctx
+#define libc_fesetenvf_ctx libc_fesetenv_ppc_ctx
+#define libc_feholdsetround_ctx libc_feholdsetround_ppc_ctx
+#define libc_feholdsetroundf_ctx libc_feholdsetround_ppc_ctx
+#define libc_feresetround_ctx libc_feresetround_ppc_ctx
+#define libc_feresetroundf_ctx libc_feresetround_ppc_ctx
+#define libc_feupdateenvf_ctx libc_feupdateenv_ppc_ctx
+#define libc_feupdateenv_ctx libc_feupdateenv_ppc_ctx
+
+#endif
diff --git a/sysdeps/powerpc/fpu/math_private.h b/sysdeps/powerpc/fpu/math_private.h
index 6c00785..c8833d6 100644
--- a/sysdeps/powerpc/fpu/math_private.h
+++ b/sysdeps/powerpc/fpu/math_private.h
@@ -22,6 +22,7 @@
#include <sysdep.h>
#include <ldsodefs.h>
#include <dl-procinfo.h>
+#include <fenv_private.h>
#include_next <math_private.h>
# if __WORDSIZE == 64 || defined _ARCH_PWR4