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Diffstat (limited to 'gcc/config/avr/avr.c')
-rw-r--r--gcc/config/avr/avr.c229
1 files changed, 152 insertions, 77 deletions
diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c
index 5ac63f19..4e58c72 100644
--- a/gcc/config/avr/avr.c
+++ b/gcc/config/avr/avr.c
@@ -49,6 +49,8 @@ static int signal_function_p PARAMS ((tree));
static int sequent_regs_live PARAMS ((void));
static char * ptrreg_to_str PARAMS ((int));
static char * cond_string PARAMS ((enum rtx_code));
+static int out_adj_frame_ptr PARAMS ((FILE *, int));
+static int out_set_stack_ptr PARAMS ((FILE *, int, int));
/* Allocate registers from r25 to r8 for parameters for function calls */
@@ -332,6 +334,124 @@ sequent_regs_live ()
}
+/* Output to FILE the asm instructions to adjust the frame pointer by
+ ADJ (r29:r28 -= ADJ;) which can be positive (prologue) or negative
+ (epilogue). Returns the number of instructions generated. */
+
+static int
+out_adj_frame_ptr (file, adj)
+ FILE *file;
+ int adj;
+{
+ int size = 0;
+
+ if (adj)
+ {
+ /* For -mtiny-stack, the high byte (r29) does not change -
+ prefer "subi" (1 cycle) over "sbiw" (2 cycles). */
+
+ if (adj < -63 || adj > 63 || TARGET_TINY_STACK)
+ {
+ fprintf (file, (AS2 (subi, r28, lo8(%d)) CR_TAB), adj);
+ size++;
+
+ if (TARGET_TINY_STACK)
+ {
+ /* In addition to any local data, each level of function calls
+ needs at least 4 more bytes of stack space for the saved
+ frame pointer and return address. So, (255 - 16) leaves
+ room for 4 levels of function calls. */
+
+ if (adj < -(255 - 16) || adj > (255 - 16))
+ fatal ("Frame pointer change (%d) too big for -mtiny-stack",
+ adj);
+ }
+ else
+ {
+ fprintf (file, (AS2 (sbci, r29, hi8(%d)) CR_TAB), adj);
+ size++;
+ }
+ }
+ else if (adj < 0)
+ {
+ fprintf (file, (AS2 (adiw, r28, %d) CR_TAB), -adj);
+ size++;
+ }
+ else
+ {
+ fprintf (file, (AS2 (sbiw, r28, %d) CR_TAB), adj);
+ size++;
+ }
+ }
+ return size;
+}
+
+
+/* Output to FILE the asm instructions to copy r29:r28 to SPH:SPL,
+ handling various cases of interrupt enable flag state BEFORE and AFTER
+ (0=disabled, 1=enabled, -1=unknown/unchanged) and target_flags.
+ Returns the number of instructions generated. */
+
+static int
+out_set_stack_ptr (file, before, after)
+ FILE *file;
+ int before;
+ int after;
+{
+ int do_sph, do_cli, do_save, size;
+
+ if (TARGET_NO_INTERRUPTS)
+ {
+ before = 0;
+ after = 0;
+ }
+
+ do_sph = !TARGET_TINY_STACK;
+ do_cli = (before != 0 && (after == 0 || do_sph));
+ do_save = (before == -1 && after == -1 && do_cli);
+ size = 1;
+
+ if (do_save)
+ {
+ fprintf (file, AS2 (in, __tmp_reg__, __SREG__) CR_TAB);
+ size++;
+ }
+
+ if (do_cli)
+ {
+ fprintf (file, "cli" CR_TAB);
+ size++;
+ }
+
+ /* Do SPH first - maybe this will disable interrupts for one instruction
+ someday, much like x86 does when changing SS (a suggestion has been
+ sent to avr@atmel.com for consideration in future devices). */
+ if (do_sph)
+ {
+ fprintf (file, AS2 (out, __SP_H__, r29) CR_TAB);
+ size++;
+ }
+
+ /* Set/restore the I flag now - interrupts will be really enabled only
+ after the next instruction starts. This was not clearly documented.
+ XXX - verify this on the new devices with enhanced AVR core. */
+ if (do_save)
+ {
+ fprintf (file, AS2 (out, __SREG__, __tmp_reg__) CR_TAB);
+ size++;
+ }
+ else if (after == 1 && (before != 1 || do_cli))
+ {
+ fprintf (file, "sei" CR_TAB);
+ size++;
+ }
+
+ fprintf (file, AS2 (out, __SP_L__, r28) "\n");
+
+ return size;
+}
+
+
/* Output function prologue */
void
@@ -392,8 +512,8 @@ function_prologue (FILE *file, int size)
else if (minimize && (frame_pointer_needed || live_seq > 6))
{
fprintf (file, ("\t"
- AS2 (ldi, r26, %d) CR_TAB
- AS2 (ldi, r27, %d) CR_TAB), size & 0xff, size / 0x100);
+ AS2 (ldi, r26, lo8(%d)) CR_TAB
+ AS2 (ldi, r27, hi8(%d)) CR_TAB), size, size);
fprintf (file, (AS2 (ldi, r30, pm_lo8(.L_%s_body)) CR_TAB
AS2 (ldi, r31, pm_hi8(.L_%s_body)) CR_TAB)
@@ -444,44 +564,20 @@ function_prologue (FILE *file, int size)
prologue_size += 4;
if (size)
{
- if (size > 63)
- {
- fprintf (file, ("\t"
- AS2 (subi,r28,%d) CR_TAB
- AS2 (sbci,r29,%d) CR_TAB)
- , size & 0xff, size / 0x100);
- prologue_size += 2;
- }
- else
- {
- fprintf (file, "\t" AS2 (sbiw,r28,%d) CR_TAB, size);
- ++prologue_size;
- }
+ fputs ("\t", file);
+ prologue_size += out_adj_frame_ptr (file, size);
+
if (interrupt_func_p)
{
- fprintf (file,
- "cli" CR_TAB
- AS2 (out,__SP_L__,r28) CR_TAB
- "sei" CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- prologue_size += 4;
+ prologue_size += out_set_stack_ptr (file, -1, 1);
}
- else if (signal_func_p || TARGET_NO_INTERRUPTS)
+ else if (signal_func_p)
{
- fprintf (file,
- AS2 (out,__SP_L__,r28) CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- prologue_size += 2;
+ prologue_size += out_set_stack_ptr (file, 0, 0);
}
else
{
- fprintf (file,
- AS2 (in,__tmp_reg__,__SREG__) CR_TAB
- "cli" CR_TAB
- AS2 (out,__SP_L__,r28) CR_TAB
- AS2 (out,__SREG__,__tmp_reg__) CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- prologue_size += 5;
+ prologue_size += out_set_stack_ptr (file, -1, -1);
}
}
}
@@ -533,20 +629,7 @@ function_epilogue (FILE *file, int size)
++epilogue_size;
if (frame_pointer_needed)
{
- if (size)
- {
- if (size > 63)
- {
- fprintf (file, AS2 (subi,r28,lo8(-%d)) CR_TAB, size);
- fprintf (file, AS2 (sbci,r29,hi8(-%d)) CR_TAB, size);
- epilogue_size += 2;
- }
- else
- {
- fprintf (file, AS2 (adiw,r28,%d) CR_TAB, size);
- ++epilogue_size;
- }
- }
+ epilogue_size += out_adj_frame_ptr (file, -size);
}
else
{
@@ -574,41 +657,16 @@ function_epilogue (FILE *file, int size)
{
if (size)
{
- if (size > 63)
- {
- fprintf (file, "\t" AS2 (subi,r28,lo8(-%d)) CR_TAB, size);
- fprintf (file, AS2 (sbci,r29,hi8(-%d)) CR_TAB, size);
- epilogue_size += 2;
- }
- else
- {
- fprintf (file, "\t" AS2 (adiw,r28,%d) CR_TAB, size);
- ++epilogue_size;
- }
+ fputs ("\t", file);
+ epilogue_size += out_adj_frame_ptr (file, -size);
+
if (interrupt_func_p | signal_func_p)
{
- fprintf (file,
- "cli" CR_TAB
- AS2 (out,__SP_L__,r28) CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- epilogue_size += 3;
- }
- else if (TARGET_NO_INTERRUPTS)
- {
- fprintf (file,
- AS2 (out,__SP_L__,r28) CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- epilogue_size += 2;
+ epilogue_size += out_set_stack_ptr (file, -1, 0);
}
else
{
- fprintf (file,
- AS2 (in,__tmp_reg__,__SREG__) CR_TAB
- "cli" CR_TAB
- AS2 (out,__SP_L__,r28) CR_TAB
- AS2 (out,__SREG__,__tmp_reg__) CR_TAB
- AS2 (out,__SP_H__,r29) "\n");
- epilogue_size += 5;
+ epilogue_size += out_set_stack_ptr (file, -1, -1);
}
}
fprintf (file, "\t"
@@ -3886,3 +3944,20 @@ jump_over_one_insn_p (insn, dest)
int dest_addr = insn_addresses[uid];
return dest_addr - jump_addr == 2;
}
+
+/* Returns 1 if a value of mode MODE can be stored starting with hard
+ register number REGNO. On the enhanced core, it should be a win to
+ align modes larger than QI on even register numbers (even if < 24).
+ so that the "movw" instruction can be used on them. */
+
+int
+avr_hard_regno_mode_ok (regno, mode)
+ int regno;
+ enum machine_mode mode;
+{
+ if (mode == QImode)
+ return 1;
+ if (regno < 24 /* && !TARGET_ENHANCED */ )
+ return 1;
+ return !(regno & 1);
+}
generated by cgit v1.1 at 2025-06-03 09:52:23 +0000