i386.c (i386_preferred_stack_boundary_string): New global variable.
* i386.c (i386_preferred_stack_boundary_string): New global variable.
(i386_preferred_stack_boundary): New global variable.
(override_functions): Set it. Tidy option setting code.
* i386.h (TARGET_OPTIONS): New command line option.
(i386_preferred_stack_boundary_string): Declare it.
(i386_preferred_stack_boundary): Likewise.
(PREFERRED_STACK_BOUNDARY): Use i386_preferred_stack_boundary.
From-SVN: r26527
This commit is contained in:
Jan Hubicka
Richard Henderson
parent
73fe76e496
commit
3af4bd8943
4 changed files with 88 additions and 38 deletions
|
|
@ -1,3 +1,13 @@
|
|||
Sat Apr 17 21:10:10 1999 Jan Hubicka <hubicka@freesoft.cz>
|
||||
|
||||
* i386.c (i386_preferred_stack_boundary_string): New global variable.
|
||||
(i386_preferred_stack_boundary): New global variable.
|
||||
(override_functions): Set it. Tidy option setting code.
|
||||
* i386.h (TARGET_OPTIONS): New command line option.
|
||||
(i386_preferred_stack_boundary_string): Declare it.
|
||||
(i386_preferred_stack_boundary): Likewise.
|
||||
(PREFERRED_STACK_BOUNDARY): Use i386_preferred_stack_boundary.
|
||||
|
||||
Sat Apr 17 19:22:38 1999 Jan Hubicka <hubicka@freesoft.cz>
|
||||
|
||||
* i386.c (k6_cost): Take into account the decoding time.
|
||||
|
|
|
|||
|
|
@ -203,6 +203,12 @@ char *i386_align_loops_string;
|
|||
/* Power of two alignment for non-loop jumps. */
|
||||
char *i386_align_jumps_string;
|
||||
|
||||
/* Power of two alignment for stack boundary in bytes. */
|
||||
char *i386_preferred_stack_boundary_string;
|
||||
|
||||
/* Preferred alignment for stack boundary in bits. */
|
||||
int i386_preferred_stack_boundary;
|
||||
|
||||
/* Values 1-5: see jump.c */
|
||||
int i386_branch_cost;
|
||||
char *i386_branch_cost_string;
|
||||
|
|
@ -239,16 +245,16 @@ override_options ()
|
|||
struct processor_costs *cost; /* Processor costs */
|
||||
int target_enable; /* Target flags to enable. */
|
||||
int target_disable; /* Target flags to disable. */
|
||||
} processor_target_table[]
|
||||
= {{PROCESSOR_I386_STRING, PROCESSOR_I386, &i386_cost, 0, 0},
|
||||
{PROCESSOR_I486_STRING, PROCESSOR_I486, &i486_cost, 0, 0},
|
||||
{PROCESSOR_I586_STRING, PROCESSOR_PENTIUM, &pentium_cost, 0, 0},
|
||||
{PROCESSOR_PENTIUM_STRING, PROCESSOR_PENTIUM, &pentium_cost, 0, 0},
|
||||
{PROCESSOR_I686_STRING, PROCESSOR_PENTIUMPRO, &pentiumpro_cost,
|
||||
0, 0},
|
||||
{PROCESSOR_PENTIUMPRO_STRING, PROCESSOR_PENTIUMPRO,
|
||||
&pentiumpro_cost, 0, 0},
|
||||
{PROCESSOR_K6_STRING, PROCESSOR_K6, &k6_cost, 0, 0}};
|
||||
} processor_target_table[] = {
|
||||
{PROCESSOR_I386_STRING, PROCESSOR_I386, &i386_cost, 0, 0},
|
||||
{PROCESSOR_I486_STRING, PROCESSOR_I486, &i486_cost, 0, 0},
|
||||
{PROCESSOR_I586_STRING, PROCESSOR_PENTIUM, &pentium_cost, 0, 0},
|
||||
{PROCESSOR_PENTIUM_STRING, PROCESSOR_PENTIUM, &pentium_cost, 0, 0},
|
||||
{PROCESSOR_I686_STRING, PROCESSOR_PENTIUMPRO, &pentiumpro_cost, 0, 0},
|
||||
{PROCESSOR_PENTIUMPRO_STRING, PROCESSOR_PENTIUMPRO,
|
||||
&pentiumpro_cost, 0, 0},
|
||||
{PROCESSOR_K6_STRING, PROCESSOR_K6, &k6_cost, 0, 0}
|
||||
};
|
||||
|
||||
int ptt_size = sizeof (processor_target_table) / sizeof (struct ptt);
|
||||
|
||||
|
|
@ -346,6 +352,11 @@ override_options ()
|
|||
def_align = (TARGET_486) ? 4 : 2;
|
||||
|
||||
/* Validate -malign-loops= value, or provide default. */
|
||||
#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
|
||||
i386_align_loops = 4;
|
||||
#else
|
||||
i386_align_loops = 2;
|
||||
#endif
|
||||
if (i386_align_loops_string)
|
||||
{
|
||||
i386_align_loops = atoi (i386_align_loops_string);
|
||||
|
|
@ -353,14 +364,13 @@ override_options ()
|
|||
fatal ("-malign-loops=%d is not between 0 and %d",
|
||||
i386_align_loops, MAX_CODE_ALIGN);
|
||||
}
|
||||
else
|
||||
#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
|
||||
i386_align_loops = 4;
|
||||
#else
|
||||
i386_align_loops = 2;
|
||||
#endif
|
||||
|
||||
/* Validate -malign-jumps= value, or provide default. */
|
||||
#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
|
||||
i386_align_jumps = 4;
|
||||
#else
|
||||
i386_align_jumps = def_align;
|
||||
#endif
|
||||
if (i386_align_jumps_string)
|
||||
{
|
||||
i386_align_jumps = atoi (i386_align_jumps_string);
|
||||
|
|
@ -368,14 +378,9 @@ override_options ()
|
|||
fatal ("-malign-jumps=%d is not between 0 and %d",
|
||||
i386_align_jumps, MAX_CODE_ALIGN);
|
||||
}
|
||||
else
|
||||
#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
|
||||
i386_align_jumps = 4;
|
||||
#else
|
||||
i386_align_jumps = def_align;
|
||||
#endif
|
||||
|
||||
/* Validate -malign-functions= value, or provide default. */
|
||||
i386_align_funcs = def_align;
|
||||
if (i386_align_funcs_string)
|
||||
{
|
||||
i386_align_funcs = atoi (i386_align_funcs_string);
|
||||
|
|
@ -383,19 +388,26 @@ override_options ()
|
|||
fatal ("-malign-functions=%d is not between 0 and %d",
|
||||
i386_align_funcs, MAX_CODE_ALIGN);
|
||||
}
|
||||
else
|
||||
i386_align_funcs = def_align;
|
||||
|
||||
/* Validate -mpreferred_stack_boundary= value, or provide default.
|
||||
The default of 128 bits is for Pentium III's SSE __m128. */
|
||||
i386_preferred_stack_boundary = 128;
|
||||
if (i386_preferred_stack_boundary_string)
|
||||
{
|
||||
i = atoi (i386_preferred_stack_boundary_string);
|
||||
if (i < 2 || i > 31)
|
||||
fatal ("-mpreferred_stack_boundary=%d is not between 2 and 31", i);
|
||||
i386_preferred_stack_boundary = (1 << i) * BITS_PER_UNIT;
|
||||
}
|
||||
|
||||
/* Validate -mbranch-cost= value, or provide default. */
|
||||
i386_branch_cost = 1;
|
||||
if (i386_branch_cost_string)
|
||||
{
|
||||
i386_branch_cost = atoi (i386_branch_cost_string);
|
||||
if (i386_branch_cost < 0 || i386_branch_cost > 5)
|
||||
fatal ("-mbranch-cost=%d is not between 0 and 5",
|
||||
i386_branch_cost);
|
||||
fatal ("-mbranch-cost=%d is not between 0 and 5", i386_branch_cost);
|
||||
}
|
||||
else
|
||||
i386_branch_cost = 1;
|
||||
|
||||
/* Keep nonleaf frame pointers. */
|
||||
if (TARGET_OMIT_LEAF_FRAME_POINTER)
|
||||
|
|
|
|||
|
|
@ -182,10 +182,10 @@ extern const int x86_double_with_add;
|
|||
{ "hard-float", MASK_80387, "Use hardware fp" }, \
|
||||
{ "soft-float", -MASK_80387, "Do not use hardware fp" },\
|
||||
{ "no-soft-float", MASK_80387, "Use hardware fp" }, \
|
||||
{ "386", 0, "Optimize for i80386" }, \
|
||||
{ "486", 0, "Optimize for i80486" }, \
|
||||
{ "pentium", 0, "Optimize for Pentium" }, \
|
||||
{ "pentiumpro", 0, "Optimize for Pentium Pro, Pentium II" },\
|
||||
{ "386", 0, "Same as -mcpu=i386" }, \
|
||||
{ "486", 0, "Same as -mcpu=i486" }, \
|
||||
{ "pentium", 0, "Same as -mcpu=pentium" }, \
|
||||
{ "pentiumpro", 0, "Same as -mcpu=pentiumpro" }, \
|
||||
{ "rtd", MASK_RTD, "Alternate calling convention" },\
|
||||
{ "no-rtd", -MASK_RTD, "Use normal calling convention" },\
|
||||
{ "align-double", MASK_ALIGN_DOUBLE, "Align some doubles on dword boundary" },\
|
||||
|
|
@ -265,6 +265,7 @@ extern int ix86_arch;
|
|||
{ "align-loops=", &i386_align_loops_string, "Loop code aligned to this power of 2" }, \
|
||||
{ "align-jumps=", &i386_align_jumps_string, "Jump targets are aligned to this power of 2" }, \
|
||||
{ "align-functions=", &i386_align_funcs_string, "Function starts are aligned to this power of 2" }, \
|
||||
{ "preferred-stack-boundary=", &i386_preferred_stack_boundary_string, "Attempt to keep stack aligned to this power of 2" }, \
|
||||
{ "branch-cost=", &i386_branch_cost_string, "Branches are this expensive (1-5, arbitrary units)" }, \
|
||||
SUBTARGET_OPTIONS \
|
||||
}
|
||||
|
|
@ -407,13 +408,12 @@ extern int ix86_arch;
|
|||
/* Allocation boundary (in *bits*) for storing arguments in argument list. */
|
||||
#define PARM_BOUNDARY 32
|
||||
|
||||
/* Boundary (in *bits*) on which stack pointer should be aligned. */
|
||||
/* Boundary (in *bits*) on which the stack pointer must be aligned. */
|
||||
#define STACK_BOUNDARY 32
|
||||
|
||||
/* We want to keep the stack aligned to 128 bits when possible, for the
|
||||
benefit of doubles and SSE __m128. But the compiler can not rely on
|
||||
the stack having this alignment.*/
|
||||
#define PREFERRED_STACK_BOUNDARY 128
|
||||
/* Boundary (in *bits*) on which the stack pointer preferrs to be
|
||||
aligned; the compiler cannot rely on having this alignment. */
|
||||
#define PREFERRED_STACK_BOUNDARY i386_preferred_stack_boundary
|
||||
|
||||
/* Allocation boundary (in *bits*) for the code of a function.
|
||||
For i486, we get better performance by aligning to a cache
|
||||
|
|
@ -2781,11 +2781,13 @@ extern char *i386_regparm_string; /* # registers to use to pass args */
|
|||
extern char *i386_align_loops_string; /* power of two alignment for loops */
|
||||
extern char *i386_align_jumps_string; /* power of two alignment for non-loop jumps */
|
||||
extern char *i386_align_funcs_string; /* power of two alignment for functions */
|
||||
extern char *i386_preferred_stack_boundary_string;/* power of two alignment for stack boundary */
|
||||
extern char *i386_branch_cost_string; /* values 1-5: see jump.c */
|
||||
extern int i386_regparm; /* i386_regparm_string as a number */
|
||||
extern int i386_align_loops; /* power of two alignment for loops */
|
||||
extern int i386_align_jumps; /* power of two alignment for non-loop jumps */
|
||||
extern int i386_align_funcs; /* power of two alignment for functions */
|
||||
extern int i386_preferred_stack_boundary; /* preferred stack boundary alignment in bits */
|
||||
extern int i386_branch_cost; /* values 1-5: see jump.c */
|
||||
extern char *hi_reg_name[]; /* names for 16 bit regs */
|
||||
extern char *qi_reg_name[]; /* names for 8 bit regs (low) */
|
||||
|
|
|
|||
|
|
@ -342,7 +342,7 @@ in the following sections.
|
|||
-mno-wide-multiply -mrtd -malign-double
|
||||
-mreg-alloc=@var{list} -mregparm=@var{num}
|
||||
-malign-jumps=@var{num} -malign-loops=@var{num}
|
||||
-malign-functions=@var{num}
|
||||
-malign-functions=@var{num} -mpreferred_stack_boundary=@var{num}
|
||||
|
||||
@emph{HPPA Options}
|
||||
-mbig-switch -mdisable-fpregs -mdisable-indexing
|
||||
|
|
@ -5172,6 +5172,32 @@ If @samp{-malign-functions} is not specified, the default is 2 if optimizing
|
|||
for a 386, and 4 if optimizing for a 486.
|
||||
@end table
|
||||
|
||||
@item -mpreferred-stack-boundary=@var{num}
|
||||
Attempt to keep the stack boundary aligned to a 2 raised to @var{num}
|
||||
byte boundary. If @samp{-mpreferred-stack-boundary} is not specified,
|
||||
the default is 4 (16 bytes or 128 bits).
|
||||
|
||||
The stack is required to be aligned on a 4 byte boundary. On Pentium
|
||||
and PentiumPro, @code{double} and @code{long double} values should be
|
||||
aligned to an 8 byte boundary (see @samp{-malign-double}) or suffer
|
||||
significant run time performance penalties. On Pentium III, the
|
||||
Streaming SIMD Extention (SSE) data type @code{__m128} suffers similar
|
||||
penalties if it is not 16 byte aligned.
|
||||
|
||||
To ensure proper alignment of this values on the stack, the stack boundary
|
||||
must be as aligned as that required by any value stored on the stack.
|
||||
Further, every function must be generated such that it keeps the stack
|
||||
aligned. Thus calling a function compiled with a higher preferred
|
||||
stack boundary from a function compiled with a lower preferred stack
|
||||
boundary will most likely misalign the stack. It is recommended that
|
||||
libraries that use callbacks always use the default setting.
|
||||
|
||||
This extra alignment does consume extra stack space. Code that is sensitive
|
||||
to stack space usage, such as embedded systems and operating system kernels,
|
||||
may want to reduce the preferred alignment to
|
||||
@samp{-mpreferred-stack-boundary=2}.
|
||||
@end table
|
||||
|
||||
@node HPPA Options
|
||||
@subsection HPPA Options
|
||||
@cindex HPPA Options
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue