On 06/16/2011 04:46 AM, Denis Chertykov wrote:
> I forgot to said that suggestion from Bernd Schmidt about
> HARD_FRAME_POINTER_REGNUM seems very useful:
>> Maybe it would help for your port to define a separate
>> FRAME_POINTER_REGNUM, able to hold an HImode value, which then gets
>> eliminated to HARD_FRAME_POINTER_REGNUM? This mechanism is used on many
>> other ports if you need examples.
>
> It's not related to addressing modes but it's related to frame pointer bugs.
Yes, that was the first thing I did while investigating G-J's
spill failure. It didn't help that, of course, but I kept it
around in my tree anyway.
This probably doesn't apply by itself, as is, but for the record...
r~
commit 0ca9df0a8c2722e8a555c2c37d7d7b40467bc5d4
Author: Richard Henderson <r...@redhat.com>
Date: Wed Jun 15 14:03:19 2011 -0700
avr: Add soft frame pointer register.
* config/avr/avr.c (avr_can_eliminate): Simplify.
(avr_initial_elimination_offset): Likewise.
(expand_prologue): Use hard_frame_pointer_rtx.
(expand_epilogue): Likewise.
(avr_legitimize_address): Gut.
(avr_hard_regno_nregs): New.
(avr_hard_regno_ok): Allow only Pmode for arg and frame_pointers.
(avr_regno_mode_code_ok_for_base_b): Handle arg and frame pointers.
* config/avr/avr.h (FIXED_REGISTERS): Adjust arg pointer,
add soft frame pointer.
(CALL_USED_REGISTERS): Likewise.
(REG_CLASS_CONTENTS): Likewise.
(REGISTER_NAMES): Likewise.
(HARD_REGNO_NREGS): Use avr_hard_regno_nregs.
(HARD_FRAME_POINTER_REGNUM): New.
(FRAME_POINTER_REGNUM): Use soft frame pointer.
(ELIMINABLE_REGS): Eliminate from the soft frame pointer,
remove the HARD_FRAME_POINTER self-elimination.
diff --git a/gcc/config/avr/avr-protos.h b/gcc/config/avr/avr-protos.h
index 2af123c..5c60e2e 100644
--- a/gcc/config/avr/avr-protos.h
+++ b/gcc/config/avr/avr-protos.h
@@ -98,6 +98,7 @@ extern int byte_immediate_operand (rtx op, enum machine_mode
mode);
extern int test_hard_reg_class (enum reg_class rclass, rtx x);
extern int jump_over_one_insn_p (rtx insn, rtx dest);
+extern int avr_hard_regno_nregs (int regno, enum machine_mode mode);
extern int avr_hard_regno_mode_ok (int regno, enum machine_mode mode);
extern void final_prescan_insn (rtx insn, rtx *operand, int num_operands);
extern int avr_simplify_comparison_p (enum machine_mode mode,
diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c
index c6087fe..e1d6b50 100644
--- a/gcc/config/avr/avr.c
+++ b/gcc/config/avr/avr.c
@@ -493,29 +493,28 @@ avr_regs_to_save (HARD_REG_SET *set)
/* Return true if register FROM can be eliminated via register TO. */
bool
-avr_can_eliminate (const int from, const int to)
+avr_can_eliminate (int from ATTRIBUTE_UNUSED, int to)
{
- return ((from == ARG_POINTER_REGNUM && to == FRAME_POINTER_REGNUM)
- || ((from == FRAME_POINTER_REGNUM
- || from == FRAME_POINTER_REGNUM + 1)
- && !frame_pointer_needed));
+ return to == HARD_FRAME_POINTER_REGNUM;
}
/* Compute offset between arg_pointer and frame_pointer. */
int
-avr_initial_elimination_offset (int from, int to)
+avr_initial_elimination_offset (int from, int to ATTRIBUTE_UNUSED)
{
- if (from == FRAME_POINTER_REGNUM && to == STACK_POINTER_REGNUM)
- return 0;
- else
- {
- int offset = frame_pointer_needed ? 2 : 0;
- int avr_pc_size = AVR_HAVE_EIJMP_EICALL ? 3 : 2;
+ int offset = 0;
+ if (from == ARG_POINTER_REGNUM)
+ {
+ offset += AVR_HAVE_EIJMP_EICALL ? 3 : 2;
+ offset += frame_pointer_needed ? 2 : 0;
offset += avr_regs_to_save (NULL);
- return get_frame_size () + (avr_pc_size) + 1 + offset;
+ offset += get_frame_size ();
+ offset += 1; /* post-dec stack space */
}
+
+ return offset;
}
/* Actual start of frame is virtual_stack_vars_rtx this is offset from
@@ -747,12 +746,12 @@ expand_prologue (void)
notes to the front. Thus we build them in the reverse order of
how we want dwarf2out to process them. */
- /* The function does always set frame_pointer_rtx, but whether that
+ /* The function does always set hard_frame_pointer_rtx, but whether that
is going to be permanent in the function is frame_pointer_needed. */
add_reg_note (insn, REG_CFA_ADJUST_CFA,
gen_rtx_SET (VOIDmode,
(frame_pointer_needed
- ? frame_pointer_rtx : stack_pointer_rtx),
+ ? hard_frame_pointer_rtx : stack_pointer_rtx),
plus_constant (stack_pointer_rtx,
-(size + live_seq))));
@@ -793,7 +792,7 @@ expand_prologue (void)
if (!size)
{
- insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+ insn = emit_move_insn (hard_frame_pointer_rtx,
stack_pointer_rtx);
RTX_FRAME_RELATED_P (insn) = 1;
}
else
@@ -816,12 +815,12 @@ expand_prologue (void)
{
/* The high byte (r29) doesn't change. Prefer 'subi'
(1 cycle) over 'sbiw' (2 cycles, same size). */
- myfp = gen_rtx_REG (QImode, FRAME_POINTER_REGNUM);
+ myfp = gen_rtx_REG (QImode, HARD_FRAME_POINTER_REGNUM);
}
else
{
/* Normal sized addition. */
- myfp = frame_pointer_rtx;
+ myfp = hard_frame_pointer_rtx;
}
/* Method 1-Adjust frame pointer. */
@@ -833,12 +832,12 @@ expand_prologue (void)
instead indicate that the entire operation is complete after
the frame pointer subtraction is done. */
- emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+ emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx);
insn = emit_move_insn (myfp, plus_constant (myfp, -size));
RTX_FRAME_RELATED_P (insn) = 1;
add_reg_note (insn, REG_CFA_ADJUST_CFA,
- gen_rtx_SET (VOIDmode, frame_pointer_rtx,
+ gen_rtx_SET (VOIDmode, hard_frame_pointer_rtx,
plus_constant (stack_pointer_rtx,
-size)));
@@ -847,23 +846,23 @@ expand_prologue (void)
need not be annotated at all. */
if (AVR_HAVE_8BIT_SP)
{
- emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+ emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
}
else if (TARGET_NO_INTERRUPTS
|| cfun->machine->is_signal
|| cfun->machine->is_OS_main)
{
emit_insn (gen_movhi_sp_r_irq_off (stack_pointer_rtx,
- frame_pointer_rtx));
+ hard_frame_pointer_rtx));
}
else if (cfun->machine->is_interrupt)
{
emit_insn (gen_movhi_sp_r_irq_on (stack_pointer_rtx,
- frame_pointer_rtx));
+ hard_frame_pointer_rtx));
}
else
{
- emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+ emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
}
fp_plus_insns = get_insns ();
@@ -880,7 +879,7 @@ expand_prologue (void)
insn = emit_move_insn (stack_pointer_rtx, insn);
RTX_FRAME_RELATED_P (insn) = 1;
- insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+ insn = emit_move_insn (hard_frame_pointer_rtx,
stack_pointer_rtx);
RTX_FRAME_RELATED_P (insn) = 1;
sp_plus_insns = get_insns ();
@@ -997,13 +996,13 @@ expand_epilogue (bool sibcall_p)
if (frame_pointer_needed)
{
/* Get rid of frame. */
- emit_move_insn(frame_pointer_rtx,
- gen_rtx_PLUS (HImode, frame_pointer_rtx,
- gen_int_mode (size, HImode)));
+ emit_move_insn (hard_frame_pointer_rtx,
+ gen_rtx_PLUS (HImode, hard_frame_pointer_rtx,
+ gen_int_mode (size, HImode)));
}
else
{
- emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+ emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx);
}
emit_insn (gen_epilogue_restores (gen_int_mode (live_seq, HImode)));
@@ -1022,12 +1021,12 @@ expand_epilogue (bool sibcall_p)
{
/* The high byte (r29) doesn't change - prefer 'subi'
(1 cycle) over 'sbiw' (2 cycles, same size). */
- myfp = gen_rtx_REG (QImode, FRAME_POINTER_REGNUM);
+ myfp = gen_rtx_REG (QImode, HARD_FRAME_POINTER_REGNUM);
}
else
{
/* Normal sized addition. */
- myfp = frame_pointer_rtx;
+ myfp = hard_frame_pointer_rtx;
}
/* Method 1-Adjust frame pointer. */
@@ -1038,22 +1037,22 @@ expand_epilogue (bool sibcall_p)
/* Copy to stack pointer. */
if (AVR_HAVE_8BIT_SP)
{
- emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+ emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
}
else if (TARGET_NO_INTERRUPTS
|| cfun->machine->is_signal)
{
emit_insn (gen_movhi_sp_r_irq_off (stack_pointer_rtx,
- frame_pointer_rtx));
+ hard_frame_pointer_rtx));
}
else if (cfun->machine->is_interrupt)
{
emit_insn (gen_movhi_sp_r_irq_on (stack_pointer_rtx,
- frame_pointer_rtx));
+ hard_frame_pointer_rtx));
}
else
{
- emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+ emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
}
fp_plus_insns = get_insns ();
@@ -1228,32 +1227,8 @@ avr_legitimate_address_p (enum machine_mode mode, rtx x,
bool strict)
memory address for an operand of mode MODE */
rtx
-avr_legitimize_address (rtx x, rtx oldx, enum machine_mode mode)
+avr_legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED, enum machine_mode
mode ATTRIBUTE_UNUSED)
{
- x = oldx;
- if (TARGET_ALL_DEBUG)
- {
- fprintf (stderr, "legitimize_address mode: %s", GET_MODE_NAME(mode));
- debug_rtx (oldx);
- }
-
- if (GET_CODE (oldx) == PLUS
- && REG_P (XEXP (oldx,0)))
- {
- if (REG_P (XEXP (oldx,1)))
- x = force_reg (GET_MODE (oldx), oldx);
- else if (GET_CODE (XEXP (oldx, 1)) == CONST_INT)
- {
- int offs = INTVAL (XEXP (oldx,1));
- if (frame_pointer_rtx != XEXP (oldx,0))
- if (offs > MAX_LD_OFFSET (mode))
- {
- if (TARGET_ALL_DEBUG)
- fprintf (stderr, "force_reg (big offset)\n");
- x = force_reg (GET_MODE (oldx), oldx);
- }
- }
- }
return x;
}
@@ -6096,8 +6071,7 @@ extra_constraint_Q (rtx x)
return 1; /* allocate pseudos */
else if (regno == REG_Z || regno == REG_Y)
return 1; /* strictly check */
- else if (xx == frame_pointer_rtx
- || xx == arg_pointer_rtx)
+ else if (xx == frame_pointer_rtx || xx == arg_pointer_rtx)
return 1; /* XXX frame & arg pointer checks */
}
return 0;
@@ -6280,6 +6254,18 @@ jump_over_one_insn_p (rtx insn, rtx dest)
return dest_addr - jump_addr == get_attr_length (insn) + 1;
}
+/* Returns the number of registers required to hold a value of MODE. */
+
+int
+avr_hard_regno_nregs (int regno, enum machine_mode mode)
+{
+ /* The fake registers are designed to hold exactly a pointer. */
+ if (regno == ARG_POINTER_REGNUM || regno == FRAME_POINTER_REGNUM)
+ return 1;
+
+ return (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
+}
+
/* Returns 1 if a value of mode MODE can be stored starting with hard
register number REGNO. On the enhanced core, anything larger than
1 byte must start in even numbered register for "movw" to work
@@ -6288,6 +6274,10 @@ jump_over_one_insn_p (rtx insn, rtx dest)
int
avr_hard_regno_mode_ok (int regno, enum machine_mode mode)
{
+ /* The fake registers are designed to hold exactly a pointer. */
+ if (regno == ARG_POINTER_REGNUM || regno == FRAME_POINTER_REGNUM)
+ return mode == Pmode;
+
/* Any GENERAL_REGS register can hold 8-bit values. */
/* FIXME: 8-bit values must not be disallowed for R28 or R29.
Disallowing QI et al. in these registers might lead to code like
@@ -6299,8 +6289,7 @@ avr_hard_regno_mode_ok (int regno, enum machine_mode mode)
if (GET_MODE_SIZE (mode) == 1)
return 1;
- /* All modes larger than 8 bits should start in an even register. */
-
+ /* All modes larger than 8 bits should start in an even register. */
return regno % 2 == 0;
}
@@ -6332,27 +6321,35 @@ avr_mode_code_base_reg_class (enum machine_mode mode
ATTRIBUTE_UNUSED,
/* Worker function for `REGNO_MODE_CODE_OK_FOR_BASE_P'. */
bool
-avr_regno_mode_code_ok_for_base_p (int regno, enum machine_mode mode
ATTRIBUTE_UNUSED,
- RTX_CODE outer_code, RTX_CODE index_code
ATTRIBUTE_UNUSED)
+avr_regno_mode_code_ok_for_base_p (int regno,
+ enum machine_mode mode ATTRIBUTE_UNUSED,
+ RTX_CODE outer_code,
+ RTX_CODE index_code ATTRIBUTE_UNUSED)
{
bool ok;
+ ok = (regno == REG_Z
+ || regno == REG_Y
+ || regno == ARG_POINTER_REGNUM
+ || regno == FRAME_POINTER_REGNUM);
+
switch (outer_code)
{
case PLUS:
- ok = regno == REG_Z || regno == REG_Y;
+ /* Computed above */
break;
case MEM: /* plain reg */
case POST_INC:
case PRE_DEC:
- ok = regno == REG_Z || regno == REG_Y || regno == REG_X;
+ /* As above, but also X. */
+ if (regno == REG_X)
+ ok = true;
break;
default:
ok = false;
break;
-
}
return ok;
diff --git a/gcc/config/avr/avr.h b/gcc/config/avr/avr.h
index 9c64f96..426ddec 100644
--- a/gcc/config/avr/avr.h
+++ b/gcc/config/avr/avr.h
@@ -191,7 +191,8 @@ extern GTY(()) section *progmem_section;
0,0,/* r28 r29 */\
0,0,/* r30 r31 */\
1,1,/* STACK */\
- 1,1 /* arg pointer */ }
+ 1, /* arg pointer */\
+ 1 /* frame pointer */ }
#define CALL_USED_REGISTERS { \
1,1,/* r0 r1 */ \
@@ -211,7 +212,8 @@ extern GTY(()) section *progmem_section;
0,0,/* r28 r29 */ \
1,1,/* r30 r31 */ \
1,1,/* STACK */ \
- 1,1 /* arg pointer */ }
+ 1, /* arg pointer */ \
+ 1 /* frame pointer */ }
#define REG_ALLOC_ORDER { \
24,25, \
@@ -229,7 +231,7 @@ extern GTY(()) section *progmem_section;
#define ADJUST_REG_ALLOC_ORDER order_regs_for_local_alloc ()
-#define HARD_REGNO_NREGS(REGNO, MODE) ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD
- 1) / UNITS_PER_WORD)
+#define HARD_REGNO_NREGS(REGNO, MODE) avr_hard_regno_nregs(REGNO, MODE)
#define HARD_REGNO_MODE_OK(REGNO, MODE) avr_hard_regno_mode_ok(REGNO, MODE)
@@ -279,17 +281,17 @@ enum reg_class {
{3 << REG_Z,0x00000000}, /* POINTER_Z_REGS, r30 - r31 */
\
{0x00000000,0x00000003}, /* STACK_REG, STACK */ \
{(3 << REG_Y) | (3 << REG_Z),
\
- 0x00000000}, /* BASE_POINTER_REGS, r28 - r31 */ \
+ 0x0000000c}, /* BASE_POINTER_REGS, r28 - r31,ap,fp */\
{(3 << REG_X) | (3 << REG_Y) | (3 << REG_Z), \
- 0x00000000}, /* POINTER_REGS, r26 - r31 */ \
+ 0x0000000c}, /* POINTER_REGS, r26 - r31,ap,fp */ \
{(3 << REG_X) | (3 << REG_Y) | (3 << REG_Z) | (3 << REG_W), \
0x00000000}, /* ADDW_REGS, r24 - r31 */ \
{0x00ff0000,0x00000000}, /* SIMPLE_LD_REGS r16 - r23 */ \
{(3 << REG_X)|(3 << REG_Y)|(3 << REG_Z)|(3 << REG_W)|(0xff << 16), \
- 0x00000000}, /* LD_REGS, r16 - r31 */ \
+ 0x0000000c}, /* LD_REGS, r16 - r31 */ \
{0x0000ffff,0x00000000}, /* NO_LD_REGS r0 - r15 */ \
- {0xffffffff,0x00000000}, /* GENERAL_REGS, r0 - r31 */ \
- {0xffffffff,0x00000003} /* ALL_REGS */ \
+ {0xffffffff,0x0000000c}, /* GENERAL_REGS, r0 - r31,ap,fp */ \
+ {0xffffffff,0x0000000f} /* ALL_REGS */ \
}
#define REGNO_REG_CLASS(R) avr_regno_reg_class(R)
@@ -322,16 +324,18 @@ enum reg_class {
#define STACK_POINTER_REGNUM 32
-#define FRAME_POINTER_REGNUM REG_Y
+#define HARD_FRAME_POINTER_REGNUM REG_Y
#define ARG_POINTER_REGNUM 34
+#define FRAME_POINTER_REGNUM 35
#define STATIC_CHAIN_REGNUM 2
#define ELIMINABLE_REGS { \
- {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM}, \
- {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM} \
- ,{FRAME_POINTER_REGNUM+1,STACK_POINTER_REGNUM+1}}
+ { ARG_POINTER_REGNUM, STACK_POINTER_REGNUM }, \
+ { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM }, \
+ { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM }, \
+ { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM }}
#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
OFFSET = avr_initial_elimination_offset (FROM, TO)
@@ -582,7 +586,7 @@ sprintf (STRING, "*.%s%lu", PREFIX, (unsigned long)(NUM))
"r8","r9","r10","r11","r12","r13","r14","r15", \
"r16","r17","r18","r19","r20","r21","r22","r23", \
"r24","r25","r26","r27","r28","r29","r30","r31", \
- "__SP_L__","__SP_H__","argL","argH"}
+ "__SP_L__","__SP_H__","ap","fp"}
#define FINAL_PRESCAN_INSN(insn, operand, nop) final_prescan_insn (insn,
operand,nop)
