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Commit 1c71e60e by Jan Hubicka Committed by Richard Henderson
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i386.c (SAVE_REGS_FIRST): Remove. 

        * i386.c (SAVE_REGS_FIRST): Remove.
        (ix86_initial_elimination_offset): Handle only SAVE_REGS_FIRST mode.
        (ix86_compute_frame_size): Likewise.
        (ix86_expand_prologue): Likewise.  Use pro_epilogue_adjust_stack.
        (ix86_emit_restore_regs): Remove.
        (ix86_emit_epilogue_esp_adjustment): Use pro_epilogue_adjust_stack
        when a frame pointer is in use.
        (ix86_expand_epilogue): Handle only SAVE_REGS_FIRST mode.  Use mov
        instead of pop to restore a register when profitable; emit leave
        when profitable.
        (ix86_attr_length_default): Handle pro_epilogue_adjust_stack
        as a TYPE_LEA insn.
        (ix86_adjust_cost): Handle pro_epilogue_adjust_stack as TYPE_ALU.
        * i386.md (prologue_allocate_stack): Remove.
        (epilogue_deallocate_stack): Remove.
        (pro_epilogue_adjust_stack): New.

Co-Authored-By: Richard Henderson <rth@cygnus.com>

From-SVN: r31792
parent c13fde05
Showing with 107 additions and 128 deletions
gcc/ChangeLog
2000-02-04 Jan Hubicka <jh@suse.cz>
Richard Henderson <rth@cygnus.com>
* i386.c (SAVE_REGS_FIRST): Remove.
(ix86_initial_elimination_offset): Handle only SAVE_REGS_FIRST mode.
(ix86_compute_frame_size): Likewise.
(ix86_expand_prologue): Likewise. Use pro_epilogue_adjust_stack.
(ix86_emit_restore_regs): Remove.
(ix86_emit_epilogue_esp_adjustment): Use pro_epilogue_adjust_stack
when a frame pointer is in use.
(ix86_expand_epilogue): Handle only SAVE_REGS_FIRST mode. Use mov
instead of pop to restore a register when profitable; emit leave
when profitable.
(ix86_attr_length_default): Handle pro_epilogue_adjust_stack
as a TYPE_LEA insn.
(ix86_adjust_cost): Handle pro_epilogue_adjust_stack as TYPE_ALU.
* i386.md (prologue_allocate_stack): Remove.
(epilogue_deallocate_stack): Remove.
(pro_epilogue_adjust_stack): New.
2000-02-04 Richard Henderson <rth@cygnus.com>
* function.c (diddle_return_value): Rework to use a callback function.
......
gcc/config/i386/i386.c
......@@ -41,16 +41,6 @@ Boston, MA 02111-1307, USA. */
#include "basic-block.h"
#include "ggc.h"
/* True when we want to do pushes before allocating stack to get better
scheduling.
Saving registers first is win in the most cases except for LEAVE
instruction. Macro is 0 iff we will use LEAVE. */
#define SAVED_REGS_FIRST \
(!frame_pointer_needed || (!TARGET_USE_LEAVE && !optimize_size))
#ifdef EXTRA_CONSTRAINT
/* If EXTRA_CONSTRAINT is defined, then the 'S'
constraint in REG_CLASS_FROM_LETTER will no longer work, and various
......@@ -411,7 +401,6 @@ static HOST_WIDE_INT ix86_compute_frame_size PARAMS((HOST_WIDE_INT,
int *, int *, int *));
static int ix86_nsaved_regs PARAMS((void));
static void ix86_emit_save_regs PARAMS((void));
static void ix86_emit_restore_regs PARAMS((void));
static void ix86_emit_epilogue_esp_adjustment PARAMS((int));
struct ix86_address
......@@ -1705,16 +1694,13 @@ ix86_initial_elimination_offset (from, to)
saved frame pointer if frame_pointer_needed
<- HARD_FRAME_POINTER
[saved regs if SAVED_REGS_FIRST]
[saved regs]
[padding1] \
| <- FRAME_POINTER
[frame] > tsize
|
[padding2] /
[saved regs if !SAVED_REGS_FIRST]
<- STACK_POINTER
*/
if (from == ARG_POINTER_REGNUM && to == HARD_FRAME_POINTER_REGNUM)
......@@ -1725,7 +1711,6 @@ ix86_initial_elimination_offset (from, to)
&& to == HARD_FRAME_POINTER_REGNUM)
{
ix86_compute_frame_size (get_frame_size (), &nregs, &padding1, (int *)0);
if (SAVED_REGS_FIRST)
padding1 += nregs * UNITS_PER_WORD;
return -padding1;
}
......@@ -1743,10 +1728,8 @@ ix86_initial_elimination_offset (from, to)
return tsize + nregs * UNITS_PER_WORD + frame_size;
else if (from != FRAME_POINTER_REGNUM)
abort ();
else if (SAVED_REGS_FIRST)
return tsize - padding1;
else
return tsize + nregs * UNITS_PER_WORD - padding1;
return tsize - padding1;
}
}
......@@ -1788,13 +1771,10 @@ ix86_compute_frame_size (size, nregs_on_stack, rpadding1, rpadding2)
if (stack_alignment_needed < 4)
stack_alignment_needed = 4;
if (stack_alignment_needed > preferred_alignment)
if (stack_alignment_needed > PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
abort ();
if (SAVED_REGS_FIRST)
offset += nregs * UNITS_PER_WORD;
else
total_size += nregs * UNITS_PER_WORD;
total_size += offset;
......@@ -1807,7 +1787,6 @@ ix86_compute_frame_size (size, nregs_on_stack, rpadding1, rpadding2)
}
/* Align stack boundary. */
if (!current_function_is_leaf)
padding2 = ((total_size + preferred_alignment - 1)
& -preferred_alignment) - total_size;
}
......@@ -1868,7 +1847,6 @@ ix86_expand_prologue ()
RTX_FRAME_RELATED_P (insn) = 1;
}
if (SAVED_REGS_FIRST)
ix86_emit_save_regs ();
if (tsize == 0)
......@@ -1876,10 +1854,9 @@ ix86_expand_prologue ()
else if (! TARGET_STACK_PROBE || tsize < CHECK_STACK_LIMIT)
{
if (frame_pointer_needed)
insn = emit_insn (gen_prologue_allocate_stack (stack_pointer_rtx,
stack_pointer_rtx,
GEN_INT (-tsize),
hard_frame_pointer_rtx));
insn = emit_insn (gen_pro_epilogue_adjust_stack
(stack_pointer_rtx, stack_pointer_rtx,
GEN_INT (-tsize), hard_frame_pointer_rtx));
else
insn = emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
GEN_INT (-tsize)));
......@@ -1903,9 +1880,6 @@ ix86_expand_prologue ()
CALL_INSN_FUNCTION_USAGE (insn));
}
if (!SAVED_REGS_FIRST)
ix86_emit_save_regs ();
#ifdef SUBTARGET_PROLOGUE
SUBTARGET_PROLOGUE;
#endif
......@@ -1920,25 +1894,6 @@ ix86_expand_prologue ()
emit_insn (gen_blockage ());
}
/* Emit code to pop all registers from stack. */
static void
ix86_emit_restore_regs ()
{
int pic_reg_used = flag_pic && (current_function_uses_pic_offset_table
|| current_function_uses_const_pool);
int limit = (frame_pointer_needed
? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM);
int regno;
for (regno = 0; regno < limit; regno++)
if ((regs_ever_live[regno] && !call_used_regs[regno])
|| (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used))
{
emit_insn (gen_popsi1 (gen_rtx_REG (SImode, regno)));
}
}
/* Emit code to add TSIZE to esp value. Use POP instruction when
profitable. */
......@@ -1980,7 +1935,14 @@ ix86_emit_epilogue_esp_adjustment (tsize)
}
else
{
/* If there is no frame pointer, we must still release the frame. */
/* If a frame pointer is present, we must be sure to tie the sp
to the fp so that we don't mis-schedule. */
if (frame_pointer_needed)
emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx,
stack_pointer_rtx,
GEN_INT (tsize),
hard_frame_pointer_rtx));
else
emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
GEN_INT (tsize)));
}
......@@ -1991,60 +1953,36 @@ ix86_emit_epilogue_esp_adjustment (tsize)
void
ix86_expand_epilogue ()
{
int regno;
int nregs;
int limit;
int regno;
int pic_reg_used = flag_pic && (current_function_uses_pic_offset_table
|| current_function_uses_const_pool);
int sp_valid = !frame_pointer_needed || current_function_sp_is_unchanging;
HOST_WIDE_INT offset;
HOST_WIDE_INT tsize = ix86_compute_frame_size (get_frame_size (), &nregs, (int *)0,
(int *)0);
HOST_WIDE_INT tsize = ix86_compute_frame_size (get_frame_size (), &nregs,
(int *)0, (int *)0);
/* SP is often unreliable so we may have to go off the frame pointer. */
offset = -(tsize + nregs * UNITS_PER_WORD);
/* Calculate start of saved registers relative to ebp. */
offset = -nregs * UNITS_PER_WORD;
if (SAVED_REGS_FIRST)
{
if (!sp_valid)
#ifdef FUNCTION_BLOCK_PROFILER_EXIT
if (profile_block_flag == 2)
{
if (nregs)
emit_insn (gen_rtx_SET (VOIDmode, stack_pointer_rtx,
gen_rtx_PLUS (SImode, hard_frame_pointer_rtx,
GEN_INT (- nregs * UNITS_PER_WORD))));
else
emit_insn (gen_epilogue_deallocate_stack (stack_pointer_rtx,
hard_frame_pointer_rtx));
}
else if (tsize)
ix86_emit_epilogue_esp_adjustment (tsize);
ix86_emit_restore_regs ();
FUNCTION_BLOCK_PROFILER_EXIT;
}
#endif
/* If we're only restoring one register and sp is not valid then
using a move instruction to restore the register since it's
less work than reloading sp and popping the register. Otherwise,
restore sp (if necessary) and pop the registers. */
else if (nregs > 1 || sp_valid)
less work than reloading sp and popping the register. */
if (!sp_valid && nregs <= 1)
{
if (!sp_valid)
{
rtx addr_offset;
addr_offset = adj_offsettable_operand (AT_BP (QImode), offset);
addr_offset = XEXP (addr_offset, 0);
if (!frame_pointer_needed)
abort();
emit_insn (gen_rtx_SET (VOIDmode, stack_pointer_rtx, addr_offset));
}
ix86_emit_restore_regs ();
}
else
{
limit = (frame_pointer_needed
? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM);
for (regno = 0; regno < limit; regno++)
for (regno = 0; regno < HARD_FRAME_POINTER_REGNUM; regno++)
if ((regs_ever_live[regno] && ! call_used_regs[regno])
|| (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used))
{
......@@ -2052,30 +1990,40 @@ ix86_expand_epilogue ()
adj_offsettable_operand (AT_BP (Pmode), offset));
offset += 4;
}
}
if (frame_pointer_needed)
{
/* If not an i386, mov & pop is faster than "leave". */
if (TARGET_USE_LEAVE || optimize_size)
emit_insn (gen_leave ());
else
{
if (!SAVED_REGS_FIRST)
emit_insn (gen_epilogue_deallocate_stack (stack_pointer_rtx,
emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx,
hard_frame_pointer_rtx,
const0_rtx,
hard_frame_pointer_rtx));
emit_insn (gen_popsi1 (hard_frame_pointer_rtx));
}
}
else if (!SAVED_REGS_FIRST && tsize)
else
{
/* First step is to deallocate the stack frame so that we can
pop the registers. */
if (!sp_valid)
{
if (!frame_pointer_needed)
abort ();
emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx,
hard_frame_pointer_rtx,
GEN_INT (offset),
hard_frame_pointer_rtx));
}
else if (tsize)
ix86_emit_epilogue_esp_adjustment (tsize);
#ifdef FUNCTION_BLOCK_PROFILER_EXIT
if (profile_block_flag == 2)
{
FUNCTION_BLOCK_PROFILER_EXIT;
for (regno = 0; regno < STACK_POINTER_REGNUM; regno++)
if ((regs_ever_live[regno] && !call_used_regs[regno])
|| (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used))
emit_insn (gen_popsi1 (gen_rtx_REG (SImode, regno)));
}
#endif
if (current_function_pops_args && current_function_args_size)
{
......@@ -5853,14 +5801,14 @@ ix86_attr_length_default (insn)
{
/* Irritatingly, single_set doesn't work with REG_UNUSED present,
as we'll get from running life_analysis during reg-stack when
not optimizing. */
not optimizing. Not that it matters anyway, now that
pro_epilogue_adjust_stack uses lea, and is by design not
single_set. */
rtx set = PATTERN (insn);
if (GET_CODE (set) == SET)
;
else if (GET_CODE (set) == PARALLEL
&& XVECLEN (set, 0) == 2
&& GET_CODE (XVECEXP (set, 0, 0)) == SET
&& GET_CODE (XVECEXP (set, 0, 1)) == CLOBBER)
&& GET_CODE (XVECEXP (set, 0, 0)) == SET)
set = XVECEXP (set, 0, 0);
else
abort ();
......@@ -6011,18 +5959,17 @@ ix86_adjust_cost (insn, link, dep_insn, cost)
if (dep_insn_code_number < 0 || recog_memoized (insn) < 0)
return cost;
/* Prologue and epilogue allocators have false dependency on ebp.
This results in one cycle extra stall on Pentium prologue scheduling, so
handle this important case manually. */
insn_type = get_attr_type (insn);
dep_insn_type = get_attr_type (dep_insn);
if ((dep_insn_code_number == CODE_FOR_prologue_allocate_stack
|| dep_insn_code_number == CODE_FOR_epilogue_deallocate_stack)
/* Prologue and epilogue allocators can have a false dependency on ebp.
This results in one cycle extra stall on Pentium prologue scheduling,
so handle this important case manually. */
if (dep_insn_code_number == CODE_FOR_pro_epilogue_adjust_stack
&& dep_insn_type == TYPE_ALU
&& !reg_mentioned_p (stack_pointer_rtx, insn))
return 0;
insn_type = get_attr_type (insn);
dep_insn_type = get_attr_type (dep_insn);
switch (ix86_cpu)
{
case PROCESSOR_PENTIUM:
......
gcc/config/i386/i386.md
......@@ -8807,16 +8807,22 @@
;;
;; in proper program order.
(define_insn "prologue_allocate_stack"
[(set (match_operand:SI 0 "register_operand" "=r")
(plus:SI (match_operand:SI 1 "register_operand" "0")
(match_operand:SI 2 "nonmemory_operand" "ri")))
(set (match_operand:SI 3 "register_operand" "=r")
(define_insn "pro_epilogue_adjust_stack"
[(set (match_operand:SI 0 "register_operand" "=r,r")
(plus:SI (match_operand:SI 1 "register_operand" "0,r")
(match_operand:SI 2 "immediate_operand" "i,i")))
(set (match_operand:SI 3 "register_operand" "+r,r")
(match_dup 3))
(clobber (reg:CC 17))]
""
"*
{
switch (get_attr_type (insn))
{
case TYPE_IMOV:
return \"mov{l}\\t{%1, %0|%0, %1}\";
case TYPE_ALU:
if (GET_CODE (operands[2]) == CONST_INT
&& (INTVAL (operands[2]) == 128
|| (INTVAL (operands[2]) < 0
......@@ -8826,16 +8832,22 @@
return \"sub{l}\\t{%2, %0|%0, %2}\";
}
return \"add{l}\\t{%2, %0|%0, %2}\";
}"
[(set_attr "type" "alu")])
(define_insn "epilogue_deallocate_stack"
[(set (match_operand:SI 0 "register_operand" "=r")
(match_operand:SI 1 "register_operand" "+r"))
(set (match_dup 1) (match_dup 1))]
""
"mov{l}\\t{%1, %0|%0, %1}"
[(set_attr "type" "imov")])
case TYPE_LEA:
operands[2] = SET_SRC (XVECEXP (PATTERN (insn), 0, 0));
return \"lea{l}\\t{%a2, %0|%0, %a2}\";
default:
abort ();
}
}"
[(set (attr "type")
(cond [(eq_attr "alternative" "0")
(const_string "alu")
(match_operand:SI 2 "const0_operand" "")
(const_string "imov")
]
(const_string "lea")))])
(define_insn "allocate_stack_worker"
[(unspec:SI [(match_operand:SI 0 "register_operand" "a")] 3)
......
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