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Added support for context switching the data used by the gcc m68k

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software floating point emulation code.  Code implemented by
Karen Sara Looney <Karen.Looney@colorado.edu> with much
email assistance from Joel.
This commit is contained in:
Joel Sherrill
1997-05-28 20:36:35 +00:00
parent 5c995d728c
commit 00d2a82897
9 changed files with 142 additions and 5 deletions
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2
c/src/exec/rtems/headers/attr.h
View File

@@ -47,7 +47,7 @@ typedef unsigned32 rtems_attribute;
#define RTEMS_NO_PRIORITY_CEILING 0x00000000
#define RTEMS_PRIORITY_CEILING 0x00000040
#if ( CPU_HARDWARE_FP == TRUE )
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
#define ATTRIBUTES_NOT_SUPPORTED 0
#else
#define ATTRIBUTES_NOT_SUPPORTED RTEMS_FLOATING_POINT

2
c/src/exec/rtems/include/rtems/rtems/attr.h
View File

@@ -47,7 +47,7 @@ typedef unsigned32 rtems_attribute;
#define RTEMS_NO_PRIORITY_CEILING 0x00000000
#define RTEMS_PRIORITY_CEILING 0x00000040
#if ( CPU_HARDWARE_FP == TRUE )
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
#define ATTRIBUTES_NOT_SUPPORTED 0
#else
#define ATTRIBUTES_NOT_SUPPORTED RTEMS_FLOATING_POINT

29
c/src/exec/score/cpu/m68k/cpu.c
View File

@@ -177,3 +177,32 @@ const unsigned char __BFFFOtable[256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
#endif
/*PAGE
*
* The following code context switches the software FPU emulation
* code provided with GCC.
*/
#if (CPU_SOFTWARE_FP == TRUE)
extern Context_Control_fp _fpCCR;
void CPU_Context_save_fp (void **fp_context_ptr)
{
Context_Control_fp *fp;
fp = (Context_Control_fp *) *fp_context_ptr;
*fp = _fpCCR;
}
void CPU_Context_restore_fp (void **fp_context_ptr)
{
Context_Control_fp *fp;
fp = (Context_Control_fp *) *fp_context_ptr;
_fpCCR = *fp;
}
#endif

72
c/src/exec/score/cpu/m68k/cpu.h
View File

@@ -52,12 +52,22 @@ extern "C" {
/*
* Some family members have no FP, some have an FPU such as the
* MC68881/MC68882 for the MC68020, others have it built in (MC68030, 040).
*
* NOTE: If on a CPU without hardware FP, then one can use software
* emulation. The gcc software FP emulation code has data which
* must be contexted switched on a per task basis.
*/
#if ( M68K_HAS_FPU == 1 )
#define CPU_HARDWARE_FP TRUE
#define CPU_SOFTWARE_FP FALSE
#else
#define CPU_HARDWARE_FP FALSE
#if defined(__GCC__)
#define CPU_SOFTWARE_FP TRUE
#else
#define CPU_SOFTWARE_FP FALSE
#endif
#endif
/*
@@ -107,6 +117,38 @@ typedef struct {
void *a7_msp; /* (a7) master stack pointer */
} Context_Control;
/*
* Floating point context ares
*/
#if (CPU_SOFTWARE_FP == TRUE)
/*
* This is the same as gcc's view of the software FP condition code
* register _fpCCR. The implementation of the emulation code is
* in the gcc-VERSION/config/m68k directory. This structure is
* correct as of gcc 2.7.2.2.
*/
typedef struct {
unsigned16 _exception_bits;
unsigned16 _trap_enable_bits;
unsigned16 _sticky_bits;
unsigned16 _rounding_mode;
unsigned16 _format;
unsigned16 _last_operation;
union {
float sf;
double df;
} _operand1;
union {
float sf;
double df;
} _operand2;
} Context_Control_fp;
#else
/*
* FP context save area for the M68881/M68882 numeric coprocessors.
*/
@@ -117,6 +159,7 @@ typedef struct {
/* 12 bytes for FMOVEM CREGS */
/* 4 bytes for non-null flag */
} Context_Control_fp;
#endif
/*
* The following structure defines the set of information saved
@@ -291,6 +334,34 @@ unsigned32 _CPU_ISR_Get_level( void );
: "0" ((_the_context)->sr), "1" ((_the_context)->a7_msp) ); \
}
/*
* Floating Point Context Area Support routines
*/
#if (CPU_SOFTWARE_FP == TRUE)
/*
* This software FP implementation is only for GCC.
*/
#define _CPU_Context_Fp_start( _base, _offset ) \
((void *) _Addresses_Add_offset( (_base), (_offset) ) )
#define _CPU_Context_Initialize_fp( _fp_area ) \
{ \
Context_Control_fp *_fp; \
_fp = *(Context_Control_fp **)_fp_area; \
_fp->_exception_bits = 0; \
_fp->_trap_enable_bits = 0; \
_fp->_sticky_bits = 0; \
_fp->_rounding_mode = 0; /* ROUND_TO_NEAREST */ \
_fp->_format = 0; /* NIL */ \
_fp->_last_operation = 0; /* NOOP */ \
_fp->_operand1.df = 0; \
_fp->_operand2.df = 0; \
}
#else
#define _CPU_Context_Fp_start( _base, _offset ) \
((void *) \
_Addresses_Add_offset( \
@@ -305,6 +376,7 @@ unsigned32 _CPU_ISR_Get_level( void );
*(--(_fp_context)) = 0; \
*(_fp_area) = (unsigned8 *)(_fp_context); \
}
#endif
/* end of Context handler macros */

7
c/src/exec/score/cpu/m68k/cpu_asm.s
View File

@@ -51,8 +51,14 @@ restore: movml a0@,d1-d7/a2-a7 | restore context
*
* CPU_FP_CONTEXT_SIZE is higher than expected to account for the
* -1 pushed at end of this sequence.
*
* Neither of these entries is required if we have software FPU
* emulation. But if we don't have an FPU or emulation, then
* we need the stub versions of these routines.
*/
#if (CPU_SOFTWARE_FP == FALSE)
.set FPCONTEXT_ARG, 4 | save FP context argument
.align 4
@@ -86,6 +92,7 @@ norst: frestore a0@+ | restore the fp state frame
movl a0,a1@ | save pointer to saved context
#endif
rts
#endif
/*PAGE
* void _ISR_Handler()

2
c/src/exec/score/src/thread.c
View File

@@ -212,7 +212,7 @@ void _Thread_Start_multitasking( void )
*/
#if ( CPU_HARDWARE_FP == TRUE )
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
/*
* don't need to worry about saving BSP's floating point state
*/

2
cpukit/rtems/include/rtems/rtems/attr.h
View File

@@ -47,7 +47,7 @@ typedef unsigned32 rtems_attribute;
#define RTEMS_NO_PRIORITY_CEILING 0x00000000
#define RTEMS_PRIORITY_CEILING 0x00000040
#if ( CPU_HARDWARE_FP == TRUE )
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
#define ATTRIBUTES_NOT_SUPPORTED 0
#else
#define ATTRIBUTES_NOT_SUPPORTED RTEMS_FLOATING_POINT

29
cpukit/score/cpu/m68k/cpu.c
View File

@@ -177,3 +177,32 @@ const unsigned char __BFFFOtable[256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
#endif
/*PAGE
*
* The following code context switches the software FPU emulation
* code provided with GCC.
*/
#if (CPU_SOFTWARE_FP == TRUE)
extern Context_Control_fp _fpCCR;
void CPU_Context_save_fp (void **fp_context_ptr)
{
Context_Control_fp *fp;
fp = (Context_Control_fp *) *fp_context_ptr;
*fp = _fpCCR;
}
void CPU_Context_restore_fp (void **fp_context_ptr)
{
Context_Control_fp *fp;
fp = (Context_Control_fp *) *fp_context_ptr;
_fpCCR = *fp;
}
#endif

2
cpukit/score/src/thread.c
View File

@@ -212,7 +212,7 @@ void _Thread_Start_multitasking( void )
*/
#if ( CPU_HARDWARE_FP == TRUE )
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
/*
* don't need to worry about saving BSP's floating point state
*/