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Commit 3ec1b4cb by Hans-Peter Nilsson Committed by Hans-Peter Nilsson
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mmix.c: Improve comments. 

	* config/mmix/mmix.c: Improve comments.
	(mmix_target_asm_function_prologue): Drop variable
	empty_stack_frame.  Don't allocate unused slot above fp.
	(mmix_target_asm_function_epilogue): Mirror prologue changes.
	* config/mmix/mmix.h (MMIX_GNU_ABI_REG_ALLOC_ORDER): Don't have
	brace in first column.
	(enum reg_class): Ditto.
	(FIRST_PARM_OFFSET): Now 0.
	(USER_LABEL_PREFIX): Remove #if 0:d definition.

From-SVN: r50538
parent 0c1fcb02
Showing with 52 additions and 72 deletions
gcc/ChangeLog
2002-03-10 Hans-Peter Nilsson <hp@bitrange.com>
* config/mmix/mmix.c: Improve comments.
(mmix_target_asm_function_prologue): Drop variable
empty_stack_frame. Don't allocate unused slot above fp.
(mmix_target_asm_function_epilogue): Mirror prologue changes.
* config/mmix/mmix.h (MMIX_GNU_ABI_REG_ALLOC_ORDER): Don't have
brace in first column.
(enum reg_class): Ditto.
(FIRST_PARM_OFFSET): Now 0.
(USER_LABEL_PREFIX): Remove #if 0:d definition.
2002-03-10 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* combine.c (make_extraction): Fix error in last change.
......
gcc/config/mmix/mmix.c
......@@ -414,7 +414,10 @@ mmix_return_addr_rtx (count, frame)
{
return count == 0
? (MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS
/* FIXME: Set frame_alias_set on the following. */
/* FIXME: Set frame_alias_set on the following. (Why?)
See mmix_initial_elimination_offset for the reason we can't use
get_hard_reg_initial_val for both. Always using a stack slot
and not a register would be suboptimal. */
? validize_mem (gen_rtx_MEM (Pmode, plus_constant (frame_pointer_rtx, -16)))
: get_hard_reg_initial_val (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM))
: NULL_RTX;
......@@ -440,7 +443,10 @@ mmix_initial_elimination_offset (fromreg, toreg)
int fp_sp_offset
= (get_frame_size () + current_function_outgoing_args_size + 7) & ~7;
/* There is no actual difference between these two. */
/* There is no actual offset between these two virtual values, but for
the frame-pointer, we have the old one in the stack position below
it, so the offset for the frame-pointer to the stack-pointer is one
octabyte larger. */
if (fromreg == MMIX_ARG_POINTER_REGNUM
&& toreg == MMIX_FRAME_POINTER_REGNUM)
return 0;
......@@ -661,14 +667,8 @@ mmix_target_asm_function_prologue (stream, locals_size)
int stack_space_to_allocate
= (current_function_outgoing_args_size
+ current_function_pretend_args_size
+ (int) locals_size + 8 + 7) & ~7;
+ (int) locals_size + 7) & ~7;
int offset = -8;
int empty_stack_frame
= (current_function_outgoing_args_size == 0
&& locals_size == 0
&& current_function_pretend_args_size == 0
&& current_function_varargs == 0
&& current_function_stdarg == 0);
int doing_dwarf = dwarf2out_do_frame ();
long cfa_offset = 0;
......@@ -752,16 +752,10 @@ mmix_target_asm_function_prologue (stream, locals_size)
}
}
/* In any case, skip over the return-address slot. FIXME: Not needed
now. */
offset -= 8;
/* Store the frame-pointer. */
if (frame_pointer_needed)
{
empty_stack_frame = 0;
if (offset < 0)
{
/* Get 8 less than otherwise, since we need to reach offset + 8. */
......@@ -799,8 +793,9 @@ mmix_target_asm_function_prologue (stream, locals_size)
if (MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS)
{
/* Store the return-address, if one is needed on the stack. */
empty_stack_frame = 0;
/* Store the return-address, if one is needed on the stack. We
usually store it in a register when needed, but that doesn't work
with -fexceptions. */
if (offset < 0)
{
......@@ -838,8 +833,6 @@ mmix_target_asm_function_prologue (stream, locals_size)
/* Store the register defining the numbering of local registers, so
we know how long to unwind the register stack. */
empty_stack_frame = 0;
if (offset < 0)
{
/* Get 8 less than otherwise, since we need to reach offset + 8. */
......@@ -894,8 +887,6 @@ mmix_target_asm_function_prologue (stream, locals_size)
&& regs_ever_live[regno] && ! call_used_regs[regno])
|| IS_MMIX_EH_RETURN_DATA_REG (regno))
{
empty_stack_frame = 0;
if (offset < 0)
{
int stack_chunk;
......@@ -950,11 +941,10 @@ mmix_target_asm_function_prologue (stream, locals_size)
offset -= 8;
}
/* Finally, allocate room for local vars (if they weren't allocated for
above) and outgoing args. This might be any number of bytes (well,
we assume it fits in a host-int).
Don't allocate (the return-address slot) if the stack frame is empty. */
if (stack_space_to_allocate && ! empty_stack_frame)
/* Finally, allocate room for outgoing args and local vars if room
wasn't allocated above. This might be any number of bytes (well, we
assume it fits in a host-int). */
if (stack_space_to_allocate)
{
if (stack_space_to_allocate < 256)
{
......@@ -1006,19 +996,13 @@ mmix_target_asm_function_epilogue (stream, locals_size)
int stack_space_to_deallocate
= (current_function_outgoing_args_size
+ current_function_pretend_args_size
+ (int) locals_size + 8 + 7) & ~7;
+ (int) locals_size + 7) & ~7;
/* The assumption that locals_size fits in an int is asserted in
mmix_target_asm_function_prologue. */
/* The first address to access is beyond the outgoing_args area. */
int offset = current_function_outgoing_args_size;
int empty_stack_frame
= (current_function_outgoing_args_size == 0
&& locals_size == 0
&& current_function_pretend_args_size == 0
&& ! MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS
&& ! MMIX_CFUN_HAS_LANDING_PAD);
/* Add the space for global non-register-stack registers.
It is assumed that the frame-pointer register can be one of these
......@@ -1059,8 +1043,6 @@ mmix_target_asm_function_epilogue (stream, locals_size)
&& regs_ever_live[regno] && !call_used_regs[regno])
|| IS_MMIX_EH_RETURN_DATA_REG (regno))
{
empty_stack_frame = 0;
if (offset > 255)
{
if (offset > 65535)
......@@ -1106,8 +1088,6 @@ mmix_target_asm_function_epilogue (stream, locals_size)
/* Get back the old frame-pointer-value. */
if (frame_pointer_needed)
{
empty_stack_frame = 0;
if (offset > 255)
{
if (offset > 65535)
......@@ -1135,27 +1115,22 @@ mmix_target_asm_function_epilogue (stream, locals_size)
offset += 8;
}
/* Do not deallocate the return-address slot if the stack frame is
empty, because then it was never allocated. */
if (! empty_stack_frame)
/* We do not need to restore pretended incoming args, just add back
offset to sp. */
if (stack_space_to_deallocate > 65535)
{
/* We do not need to restore pretended incoming args, just add
back offset to sp. */
if (stack_space_to_deallocate > 65535)
{
/* There's better support for incrementing than decrementing, so
we might be able to optimize this as we see a need. */
mmix_output_register_setting (stream, 255,
stack_space_to_deallocate, 1);
fprintf (stream, "\tADDU %s,%s,$255\n",
reg_names[MMIX_STACK_POINTER_REGNUM],
reg_names[MMIX_STACK_POINTER_REGNUM]);
}
else
fprintf (stream, "\tINCL %s,%d\n",
reg_names[MMIX_STACK_POINTER_REGNUM],
stack_space_to_deallocate);
/* There's better support for incrementing than decrementing, so
we might be able to optimize this as we see a need. */
mmix_output_register_setting (stream, 255,
stack_space_to_deallocate, 1);
fprintf (stream, "\tADDU %s,%s,$255\n",
reg_names[MMIX_STACK_POINTER_REGNUM],
reg_names[MMIX_STACK_POINTER_REGNUM]);
}
else if (stack_space_to_deallocate != 0)
fprintf (stream, "\tINCL %s,%d\n",
reg_names[MMIX_STACK_POINTER_REGNUM],
stack_space_to_deallocate);
if (current_function_calls_eh_return)
/* Adjustment the (normal) stack-pointer to that of the receiver.
......@@ -1343,9 +1318,9 @@ void
mmix_trampoline_template (stream)
FILE * stream;
{
/* Read a value from to static-chain, jump somewhere. The static chain
is stored at offset 16, and the function address is stored at offset
24. */
/* Read a value into the static-chain register and jump somewhere. The
static chain is stored at offset 16, and the function address is
stored at offset 24. */
/* FIXME: GCC copies this using *intsize* (tetra), when it should use
register size (octa). */
fprintf (stream, "\tGETA $255,1F\n\t");
......
gcc/config/mmix/mmix.h
......@@ -483,7 +483,7 @@ extern int target_flags;
assuming it is referenced a very limited number of times. Other global
and fixed registers come next; they are never allocated. */
#define MMIX_GNU_ABI_REG_ALLOC_ORDER \
{ 252, 251, 250, 249, 248, 247, 246, \
{ 252, 251, 250, 249, 248, 247, 246, \
245, 244, 243, 242, 241, 240, 239, 238, \
237, 236, 235, 234, 233, 232, 231, \
\
......@@ -549,10 +549,10 @@ extern int target_flags;
/* Node: Register Classes */
enum reg_class
{
NO_REGS, GENERAL_REGS, REMAINDER_REG, HIMULT_REG,
SYSTEM_REGS, ALL_REGS, LIM_REG_CLASSES
};
{
NO_REGS, GENERAL_REGS, REMAINDER_REG, HIMULT_REG,
SYSTEM_REGS, ALL_REGS, LIM_REG_CLASSES
};
#define N_REG_CLASSES (int) LIM_REG_CLASSES
......@@ -626,10 +626,7 @@ enum reg_class
#define STARTING_FRAME_OFFSET \
mmix_starting_frame_offset ()
/* There is a stack slot between the frame-pointer and the first
parameter, where the return address is sometimes stored. FIXME:
Unnecessary. */
#define FIRST_PARM_OFFSET(FUNDECL) 8
#define FIRST_PARM_OFFSET(FUNDECL) 0
#define DYNAMIC_CHAIN_ADDRESS(FRAMEADDR) \
mmix_dynamic_chain_address (FRAMEADDR)
......@@ -1104,10 +1101,6 @@ const_section () \
#define PRINT_OPERAND_ADDRESS(STREAM, X) \
mmix_print_operand_address (STREAM, X)
#if 0
#define USER_LABEL_PREFIX "_"
#endif
#define ASM_OUTPUT_REG_PUSH(STREAM, REGNO) \
mmix_asm_output_reg_push (STREAM, REGNO)
......
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