From 8e5e36d7ba097b8e110ab45794659156af182f54 Mon Sep 17 00:00:00 2001

From: Stefan Liebler <stli@linux.ibm.com>

Date: Wed, 11 Dec 2019 15:09:31 +0100

Subject: [PATCH 27/28] S390: Implement libc_fe* macros.

This patch provides the s390 specific implementation for

libc_feholdexcept, libc_fesetround, libc_feholdexcept_setround,

libc_fetestexcept, libc_fesetenv, libc_feupdateenv_test,

libc_feupdateenv, libc_feholdsetround_ctx, libc_feresetround_ctx,

libc_feholdsetround_noex_ctx and libc_feresetround_noex_ctx.

(cherry picked from commit 7c94d036c17dfd352d11e9bf98e5d84122c1f95e)

Note: glibc-2.28 does not have a generic fenv_private.h.

Therefore include_next does not work. Instead fenv_private.h needs to

be included in the s390 specific mathp_private.h just before including

the generic math_private.h.

As the s390 specific math_private.h is introduced with the backport of

commit "S390: Implement roundtoint and converttoint and define TOINT_INTRINSICS.",

the order of cherry-picking was changed compared to upstream!

---

 sysdeps/s390/fpu/fenv_private.h | 248 ++++++++++++++++++++++++++++++++

 sysdeps/s390/fpu/math_private.h |   1 +

 2 files changed, 249 insertions(+)

 create mode 100644 sysdeps/s390/fpu/fenv_private.h

diff --git a/sysdeps/s390/fpu/fenv_private.h b/sysdeps/s390/fpu/fenv_private.h

new file mode 100644

index 0000000000..8899f8f434

--- /dev/null

+++ b/sysdeps/s390/fpu/fenv_private.h

@@ -0,0 +1,248 @@

+/* Private floating point rounding and exceptions handling.  390/s390x version.

+   Copyright (C) 2019 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

+   <https://www.gnu.org/licenses/>.  */

+

+#ifndef S390_FENV_PRIVATE_H

+#define S390_FENV_PRIVATE_H 1

+

+#include <fenv.h>

+#include <fenv_libc.h>

+#include <fpu_control.h>

+

+static __always_inline void

+libc_feholdexcept_s390 (fenv_t *envp)

+{

+  fpu_control_t fpc, fpc_new;

+

+  /* Store the environment.  */

+  _FPU_GETCW (fpc);

+  envp->__fpc = fpc;

+

+  /* Clear the current exception flags and dxc field.

+     Hold from generating fpu exceptions temporarily.  */

+  fpc_new = fpc & ~(FPC_FLAGS_MASK | FPC_DXC_MASK | FPC_EXCEPTION_MASK);

+

+  /* Only set new environment if it has changed.  */

+  if (fpc_new != fpc)

+    _FPU_SETCW (fpc_new);

+}

+

+#define libc_feholdexcept  libc_feholdexcept_s390

+#define libc_feholdexceptf libc_feholdexcept_s390

+#define libc_feholdexceptl libc_feholdexcept_s390

+

+static __always_inline void

+libc_fesetround_s390 (int round)

+{

+  __asm__ __volatile__ ("srnm 0(%0)" : : "a" (round));

+}

+

+#define libc_fesetround  libc_fesetround_s390

+#define libc_fesetroundf libc_fesetround_s390

+#define libc_fesetroundl libc_fesetround_s390

+

+static __always_inline void

+libc_feholdexcept_setround_s390 (fenv_t *envp, int r)

+{

+  fpu_control_t fpc, fpc_new;

+

+  _FPU_GETCW (fpc);

+  envp->__fpc = fpc;

+

+  /* Clear the current exception flags and dxc field.

+     Hold from generating fpu exceptions temporarily.

+     Reset rounding mode bits.  */

+  fpc_new = fpc & ~(FPC_FLAGS_MASK | FPC_DXC_MASK | FPC_EXCEPTION_MASK

+		    | FPC_RM_MASK);

+

+  /* Set new rounding mode.  */

+  fpc_new |= (r & FPC_RM_MASK);

+

+  /* Only set new environment if it has changed.  */

+  if (fpc_new != fpc)

+    _FPU_SETCW (fpc_new);

+}

+

+#define libc_feholdexcept_setround  libc_feholdexcept_setround_s390

+#define libc_feholdexcept_setroundf libc_feholdexcept_setround_s390

+#define libc_feholdexcept_setroundl libc_feholdexcept_setround_s390

+

+static __always_inline int

+libc_fetestexcept_s390 (int excepts)

+{

+  int res;

+  fexcept_t fpc;

+

+  _FPU_GETCW (fpc);

+

+  /* Get current exceptions.  */

+  res = (fpc >> FPC_FLAGS_SHIFT) & FE_ALL_EXCEPT;

+  if ((fpc & FPC_NOT_FPU_EXCEPTION) == 0)

+    /* Bits 6, 7 of dxc-byte are zero,

+       thus bits 0-5 of dxc-byte correspond to the flag-bits.

+       Evaluate flags and last dxc-exception-code.  */

+    res |= (fpc >> FPC_DXC_SHIFT) & FE_ALL_EXCEPT;

+

+  return res & excepts;

+}

+

+#define libc_fetestexcept  libc_fetestexcept_s390

+#define libc_fetestexceptf libc_fetestexcept_s390

+#define libc_fetestexceptl libc_fetestexcept_s390

+

+static __always_inline void

+libc_fesetenv_s390 (const fenv_t *envp)

+{

+  _FPU_SETCW (envp->__fpc);

+}

+

+#define libc_fesetenv  libc_fesetenv_s390

+#define libc_fesetenvf libc_fesetenv_s390

+#define libc_fesetenvl libc_fesetenv_s390

+

+static __always_inline int

+libc_feupdateenv_test_s390 (const fenv_t *envp, int ex)

+{

+  /* Get the currently raised exceptions.  */

+  int excepts;

+  fexcept_t fpc_old;

+

+  _FPU_GETCW (fpc_old);

+

+  /* Get current exceptions.  */

+  excepts = (fpc_old >> FPC_FLAGS_SHIFT) & FE_ALL_EXCEPT;

+  if ((fpc_old & FPC_NOT_FPU_EXCEPTION) == 0)

+    /* Bits 6, 7 of dxc-byte are zero,

+       thus bits 0-5 of dxc-byte correspond to the flag-bits.

+       Evaluate flags and last dxc-exception-code.  */

+    excepts |= (fpc_old >> FPC_DXC_SHIFT) & FE_ALL_EXCEPT;

+

+  /* Merge the currently raised exceptions with those in envp.  */

+  fpu_control_t fpc_new = envp->__fpc;

+  fpc_new |= excepts << FPC_FLAGS_SHIFT;

+

+  /* Install the new fpc from envp.  */

+  if (fpc_new != fpc_old)

+    _FPU_SETCW (fpc_new);

+

+  /* Raise the exceptions if enabled in new fpc.  */

+  if (__glibc_unlikely ((fpc_new >> FPC_EXCEPTION_MASK_SHIFT) & excepts))

+    __feraiseexcept (excepts);

+

+  return excepts & ex;

+}

+

+#define libc_feupdateenv_test  libc_feupdateenv_test_s390

+#define libc_feupdateenv_testf libc_feupdateenv_test_s390

+#define libc_feupdateenv_testl libc_feupdateenv_test_s390

+

+static __always_inline void

+libc_feupdateenv_s390 (const fenv_t *envp)

+{

+  libc_feupdateenv_test_s390 (envp, 0);

+}

+

+#define libc_feupdateenv  libc_feupdateenv_s390

+#define libc_feupdateenvf libc_feupdateenv_s390

+#define libc_feupdateenvl libc_feupdateenv_s390

+

+static __always_inline fenv_t

+libc_handle_user_fenv_s390 (const fenv_t *envp)

+{

+  fenv_t env;

+  if (envp == FE_DFL_ENV)

+    {

+      env.__fpc = _FPU_DEFAULT;

+    }

+  else if (envp == FE_NOMASK_ENV)

+    {

+      env.__fpc = FPC_EXCEPTION_MASK;

+    }

+  else

+    env = (*envp);

+

+  return env;

+}

+

+/* We have support for rounding mode context.  */

+#define HAVE_RM_CTX 1

+

+static __always_inline void

+libc_feholdsetround_s390_ctx (struct rm_ctx *ctx, int r)

+{

+  fpu_control_t fpc;

+  int round;

+

+  _FPU_GETCW (fpc);

+  ctx->env.__fpc = fpc;

+

+  /* Check whether rounding modes are different.  */

+  round = fpc & FPC_RM_MASK;

+

+  /* Set the rounding mode if changed.  */

+  if (__glibc_unlikely (round != r))

+    {

+      ctx->updated_status = true;

+      libc_fesetround_s390 (r);

+    }

+  else

+    ctx->updated_status = false;

+}

+

+#define libc_feholdsetround_ctx		libc_feholdsetround_s390_ctx

+#define libc_feholdsetroundf_ctx	libc_feholdsetround_s390_ctx

+#define libc_feholdsetroundl_ctx	libc_feholdsetround_s390_ctx

+

+static __always_inline void

+libc_feresetround_s390_ctx (struct rm_ctx *ctx)

+{

+  /* Restore the rounding mode if updated.  */

+  if (__glibc_unlikely (ctx->updated_status))

+    {

+      fpu_control_t fpc;

+      _FPU_GETCW (fpc);

+      fpc = ctx->env.__fpc | (fpc & FPC_FLAGS_MASK);

+      _FPU_SETCW (fpc);

+    }

+}

+

+#define libc_feresetround_ctx		libc_feresetround_s390_ctx

+#define libc_feresetroundf_ctx		libc_feresetround_s390_ctx

+#define libc_feresetroundl_ctx		libc_feresetround_s390_ctx

+

+static __always_inline void

+libc_feholdsetround_noex_s390_ctx (struct rm_ctx *ctx, int r)

+{

+  libc_feholdexcept_setround_s390 (&ctx->env, r);

+}

+

+#define libc_feholdsetround_noex_ctx	libc_feholdsetround_noex_s390_ctx

+#define libc_feholdsetround_noexf_ctx	libc_feholdsetround_noex_s390_ctx

+#define libc_feholdsetround_noexl_ctx	libc_feholdsetround_noex_s390_ctx

+

+static __always_inline void

+libc_feresetround_noex_s390_ctx (struct rm_ctx *ctx)

+{

+  /* Restore exception flags and rounding mode.  */

+  libc_fesetenv_s390 (&ctx->env);

+}

+

+#define libc_feresetround_noex_ctx	libc_feresetround_noex_s390_ctx

+#define libc_feresetround_noexf_ctx	libc_feresetround_noex_s390_ctx

+#define libc_feresetround_noexl_ctx	libc_feresetround_noex_s390_ctx

+

+#endif

diff --git a/sysdeps/s390/fpu/math_private.h b/sysdeps/s390/fpu/math_private.h

index a1ae91a87c..f3c770d59a 100644

--- a/sysdeps/s390/fpu/math_private.h

+++ b/sysdeps/s390/fpu/math_private.h

@@ -48,6 +48,7 @@ converttoint (double_t x)

 }

 #endif

+#include <fenv_private.h>

 #include_next <math_private.h>

 #endif

-- 

2.18.2