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207 lines
7.7 KiB
207 lines
7.7 KiB
From aea6303d6c5fa276ea10887dab968ee0f3c79328 Mon Sep 17 00:00:00 2001 |
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From: Stefan Liebler <stli@linux.vnet.ibm.com> |
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Date: Thu, 8 Oct 2015 10:30:00 +0200 |
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Subject: [PATCH 04/30] S390: Fix handling of DXC-byte in FPC-register. |
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MIME-Version: 1.0 |
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Content-Type: text/plain; charset=UTF-8 |
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Content-Transfer-Encoding: 8bit |
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upstream-commit-id: 5d96fe8c0dc3450bafe6c2aae2dabc76819df3e0 |
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https://www.sourceware.org/ml/libc-alpha/2015-07/msg00074.html |
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On s390, the DXC(data-exception-code)-byte in FPC(floating-point-control)- |
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register contains a code of the last occured exception. |
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If bits 6 and 7 of DXC-byte are zero, the bits 0-5 correspond to the |
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ieee-exception flag bits. |
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The current implementation always uses these bits as ieee-exception flag bits. |
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fetestexcept() reports any exception after the first usage of a |
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vector-instruction in a process, because it raises an "vector instruction |
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exception" with DXC-code 0xFE. |
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This patch fixes the handling of the DXC-byte. The DXC-Byte is only handled |
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if bits 6 and 7 are zero. |
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The #define _FPU_RESERVED is extended by the DXC-Byte. |
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Otherwise the tests math/test-fpucw-static and math/test-fpucw-ieee-static |
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fails, because DXC-Byte contains the vector instruction exception when reaching |
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main(). This exception was triggered by strrchr() call in __init_misc(). |
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__init_misc() is called after __setfpucw () in __libc_init_first(). |
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The field __ieee_instruction_pointer in struct fenv_t is renamed to __unused |
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because it is a relict from commit "Remove PTRACE_PEEKUSER" |
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(87b9b50f0d4b92248905e95a06a13c513dc45e59) and isn´t used anymore. |
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ChangeLog: |
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[BZ #18610] |
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* sysdeps/s390/fpu/bits/fenv.h (fenv_t): Rename |
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__ieee_instruction_pointer to __unused. |
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* sysdeps/s390/fpu/fesetenv.c (__fesetenv): Remove usage of |
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__ieee_instruction_pointer. |
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* sysdeps/s390/fpu/fclrexcpt.c (feclearexcept): Fix dxc-field handling. |
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* sysdeps/s390/fpu/fgetexcptflg.c (fegetexceptflag): Likewise. |
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* sysdeps/s390/fpu/fsetexcptflg.c (fesetexceptflag): Likewise. |
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* sysdeps/s390/fpu/ftestexcept.c (fetestexcept): Likewise. |
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* sysdeps/s390/fpu/fpu_control.h (_FPU_RESERVED): |
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Mark dxc-field as reserved. |
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--- |
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sysdeps/s390/fpu/bits/fenv.h | 6 ++++-- |
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sysdeps/s390/fpu/fclrexcpt.c | 7 ++++++- |
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sysdeps/s390/fpu/fesetenv.c | 2 -- |
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sysdeps/s390/fpu/fgetexcptflg.c | 8 +++++++- |
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sysdeps/s390/fpu/fpu_control.h | 6 +++--- |
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sysdeps/s390/fpu/fsetexcptflg.c | 15 ++++++++++++--- |
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sysdeps/s390/fpu/ftestexcept.c | 12 +++++++++--- |
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7 files changed, 41 insertions(+), 15 deletions(-) |
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diff --git a/sysdeps/s390/fpu/bits/fenv.h b/sysdeps/s390/fpu/bits/fenv.h |
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index 88c6f7a..93177dc 100644 |
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--- a/sysdeps/s390/fpu/bits/fenv.h |
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+++ b/sysdeps/s390/fpu/bits/fenv.h |
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@@ -77,8 +77,10 @@ typedef unsigned int fexcept_t; /* size of fpc */ |
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typedef struct |
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{ |
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fexcept_t __fpc; |
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- void *__ieee_instruction_pointer; |
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- /* failing instruction for ieee exceptions */ |
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+ void *__unused; |
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+ /* The field __unused (formerly __ieee_instruction_pointer) is a relict from |
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+ commit "Remove PTRACE_PEEKUSER" (87b9b50f0d4b92248905e95a06a13c513dc45e59) |
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+ and isn´t used anymore. */ |
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} fenv_t; |
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/* If the default argument is used we use this value. */ |
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diff --git a/sysdeps/s390/fpu/fclrexcpt.c b/sysdeps/s390/fpu/fclrexcpt.c |
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index 3e8d9bb..c2647ba 100644 |
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--- a/sysdeps/s390/fpu/fclrexcpt.c |
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+++ b/sysdeps/s390/fpu/fclrexcpt.c |
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@@ -29,7 +29,12 @@ feclearexcept (int excepts) |
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_FPU_GETCW (temp); |
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/* Clear the relevant bits. */ |
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- temp &= ~((excepts << FPC_DXC_SHIFT)|(excepts << FPC_FLAGS_SHIFT)); |
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+ temp &= ~(excepts << FPC_FLAGS_SHIFT); |
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+ if ((temp & FPC_NOT_FPU_EXCEPTION) == 0) |
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+ /* Bits 6, 7 of dxc-byte are zero, |
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+ thus bits 0-5 of dxc-byte correspond to the flag-bits. |
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+ Clear the relevant bits in flags and dxc-field. */ |
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+ temp &= ~(excepts << FPC_DXC_SHIFT); |
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/* Put the new data in effect. */ |
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_FPU_SETCW (temp); |
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diff --git a/sysdeps/s390/fpu/fesetenv.c b/sysdeps/s390/fpu/fesetenv.c |
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index b534205..a4a0bb5 100644 |
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--- a/sysdeps/s390/fpu/fesetenv.c |
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+++ b/sysdeps/s390/fpu/fesetenv.c |
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@@ -32,12 +32,10 @@ fesetenv (const fenv_t *envp) |
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if (envp == FE_DFL_ENV) |
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{ |
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env.__fpc = _FPU_DEFAULT; |
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- env.__ieee_instruction_pointer = 0; |
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} |
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else if (envp == FE_NOMASK_ENV) |
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{ |
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env.__fpc = FPC_EXCEPTION_MASK; |
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- env.__ieee_instruction_pointer = 0; |
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} |
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else |
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env = (*envp); |
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diff --git a/sysdeps/s390/fpu/fgetexcptflg.c b/sysdeps/s390/fpu/fgetexcptflg.c |
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index 7457678..7941904 100644 |
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--- a/sysdeps/s390/fpu/fgetexcptflg.c |
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+++ b/sysdeps/s390/fpu/fgetexcptflg.c |
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@@ -27,7 +27,13 @@ fegetexceptflag (fexcept_t *flagp, int excepts) |
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/* Get the current exceptions. */ |
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_FPU_GETCW (temp); |
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- newexcepts = (excepts << FPC_DXC_SHIFT) | (excepts << FPC_FLAGS_SHIFT); |
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+ newexcepts = excepts << FPC_FLAGS_SHIFT; |
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+ if ((temp & FPC_NOT_FPU_EXCEPTION) == 0) |
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+ /* Bits 6, 7 of dxc-byte are zero, |
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+ thus bits 0-5 of dxc-byte correspond to the flag-bits. |
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+ Evaluate flags and last dxc-exception-code. */ |
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+ newexcepts |= excepts << FPC_DXC_SHIFT; |
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+ |
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*flagp = temp & newexcepts; |
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/* Success. */ |
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diff --git a/sysdeps/s390/fpu/fpu_control.h b/sysdeps/s390/fpu/fpu_control.h |
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index af81bc2..dba904d 100644 |
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--- a/sysdeps/s390/fpu/fpu_control.h |
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+++ b/sysdeps/s390/fpu/fpu_control.h |
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@@ -19,12 +19,12 @@ |
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<http://www.gnu.org/licenses/>. */ |
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#ifndef _FPU_CONTROL_H |
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-# define _FPU_CONTROL_H |
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+#define _FPU_CONTROL_H |
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-# include <features.h> |
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+#include <features.h> |
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/* These bits are reserved are not changed. */ |
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-# define _FPU_RESERVED 0x070700FC |
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+#define _FPU_RESERVED 0x0707FFFC |
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/* The fdlibm code requires no interrupts for exceptions. Don't |
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change the rounding mode, it would break long double I/O! */ |
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diff --git a/sysdeps/s390/fpu/fsetexcptflg.c b/sysdeps/s390/fpu/fsetexcptflg.c |
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index aada675..85c68e8 100644 |
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--- a/sysdeps/s390/fpu/fsetexcptflg.c |
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+++ b/sysdeps/s390/fpu/fsetexcptflg.c |
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@@ -24,16 +24,25 @@ |
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int |
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fesetexceptflag (const fexcept_t *flagp, int excepts) |
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{ |
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- fexcept_t temp,newexcepts; |
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+ fexcept_t temp, newexcepts; |
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/* Get the current environment. We have to do this since we cannot |
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separately set the status word. */ |
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_FPU_GETCW (temp); |
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/* Install the new exception bits in the Accrued Exception Byte. */ |
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excepts = excepts & FE_ALL_EXCEPT; |
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- newexcepts = (excepts << FPC_DXC_SHIFT) | (excepts << FPC_FLAGS_SHIFT); |
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+ newexcepts = excepts << FPC_FLAGS_SHIFT; |
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temp &= ~newexcepts; |
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- temp |= *flagp & newexcepts; |
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+ if ((temp & FPC_NOT_FPU_EXCEPTION) == 0) |
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+ /* Bits 6, 7 of dxc-byte are zero, |
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+ thus bits 0-5 of dxc-byte correspond to the flag-bits. |
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+ Clear given exceptions in dxc-field. */ |
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+ temp &= ~(excepts << FPC_DXC_SHIFT); |
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+ |
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+ /* Integrate dxc-byte of flagp into flags. The dxc-byte of flagp contains |
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+ either an ieee-exception or 0 (see fegetexceptflag). */ |
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+ temp |= (*flagp | ((*flagp >> FPC_DXC_SHIFT) << FPC_FLAGS_SHIFT)) |
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+ & newexcepts; |
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/* Store the new status word (along with the rest of the environment. |
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Possibly new exceptions are set but they won't get executed unless |
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diff --git a/sysdeps/s390/fpu/ftestexcept.c b/sysdeps/s390/fpu/ftestexcept.c |
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index 5594994..c36aefd 100644 |
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--- a/sysdeps/s390/fpu/ftestexcept.c |
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+++ b/sysdeps/s390/fpu/ftestexcept.c |
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@@ -23,11 +23,17 @@ |
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int |
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fetestexcept (int excepts) |
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{ |
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- fexcept_t temp; |
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+ fexcept_t temp, res; |
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/* Get current exceptions. */ |
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_FPU_GETCW (temp); |
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- temp = (temp >> FPC_DXC_SHIFT) | (temp >> FPC_FLAGS_SHIFT); |
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- return temp & excepts & FE_ALL_EXCEPT; |
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+ res = temp >> FPC_FLAGS_SHIFT; |
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+ if ((temp & FPC_NOT_FPU_EXCEPTION) == 0) |
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+ /* Bits 6, 7 of dxc-byte are zero, |
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+ thus bits 0-5 of dxc-byte correspond to the flag-bits. |
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+ Evaluate flags and last dxc-exception-code. */ |
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+ res |= temp >> FPC_DXC_SHIFT; |
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+ |
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+ return res & excepts & FE_ALL_EXCEPT; |
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} |
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libm_hidden_def (fetestexcept) |
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-- |
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2.3.0 |
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