* [PATCH] xtensa: Fix PR target/78118
@ 2016-11-01 6:33 Max Filippov
2016-11-01 16:28 ` augustine.sterling
0 siblings, 1 reply; 3+ messages in thread
From: Max Filippov @ 2016-11-01 6:33 UTC (permalink / raw)
To: gcc-patches; +Cc: linux-xtensa, Sterling Augustine, Max Filippov
It started failing after the following commit: 32e90dc6a0cda45 ("PR
rtl-optimization/61047").
The change that made xtensa backend go ICE looks completely unrelated,
and indeed, the issue is caused by the side effect of
compute_frame_size() function call hidden in the
INITIAL_ELIMINATION_OFFSET macro. This call updates the value of the
xtensa_current_frame_size static variable, used in "return" instruction
predicate. Prior to the change the value of xtensa_current_frame_size was
set to 0 after the end of epilogue generation, which enabled the "return"
instruction for the CALL0 ABI, but after the change the additional
INITIAL_ELIMINATION_OFFSET calls make xtensa_current_frame_size non-zero
and "return" pattern unavailable.
Get rid of the global xtensa_current_frame_size and
xtensa_callee_save_size variables by moving them into the
machine_function structure. Implement predicate for the "return" pattern
as a function. Don't communicate completion of epilogue generation
through zeroing of xtensa_current_frame_size, add explicit epilogue_done
variable to the machine_function structure. Don't update stack frame
layout after the completion of reload.
2016-10-26 Max Filippov <jcmvbkbc@gmail.com>
gcc/
* config/xtensa/xtensa-protos.h
(xtensa_use_return_instruction_p): New prototype.
* config/xtensa/xtensa.c (xtensa_current_frame_size,
xtensa_callee_save_size): Remove.
(struct machine_function): Add new fields: current_frame_size,
callee_save_size, frame_laid_out and epilogue_done.
(compute_frame_size, xtensa_expand_prologue,
xtensa_expand_epilogue): Replace xtensa_callee_save_size with
cfun->machine->callee_save_size and xtensa_current_frame_size
with cfun->machine->current_frame_size.
(compute_frame_size): Update cfun->machine->frame_laid_out and
don't update frame layout after reload completion.
(xtensa_expand_epilogue): Set cfun->machine->epilogue_done
instead of zeroing xtensa_current_frame_size.
(xtensa_use_return_instruction_p): New function.
* config/xtensa/xtensa.h (xtensa_current_frame_size): Remove
declaration.
(INITIAL_ELIMINATION_OFFSET): Use return value of
compute_frame_size instead of xtensa_current_frame_size value.
* config/xtensa/xtensa.md ("return" pattern): Use new predicate
function xtensa_use_return_instruction_p instead of inline code.
---
gcc/config/xtensa/xtensa-protos.h | 1 +
gcc/config/xtensa/xtensa.c | 82 ++++++++++++++++++++++++---------------
gcc/config/xtensa/xtensa.h | 6 +--
gcc/config/xtensa/xtensa.md | 2 +-
4 files changed, 55 insertions(+), 36 deletions(-)
diff --git a/gcc/config/xtensa/xtensa-protos.h b/gcc/config/xtensa/xtensa-protos.h
index f2ca526..873557f 100644
--- a/gcc/config/xtensa/xtensa-protos.h
+++ b/gcc/config/xtensa/xtensa-protos.h
@@ -68,6 +68,7 @@ extern rtx xtensa_return_addr (int, rtx);
extern void xtensa_setup_frame_addresses (void);
extern int xtensa_dbx_register_number (int);
extern long compute_frame_size (int);
+extern bool xtensa_use_return_instruction_p (void);
extern void xtensa_expand_prologue (void);
extern void xtensa_expand_epilogue (void);
extern void order_regs_for_local_alloc (void);
diff --git a/gcc/config/xtensa/xtensa.c b/gcc/config/xtensa/xtensa.c
index 60e5029..2115b57 100644
--- a/gcc/config/xtensa/xtensa.c
+++ b/gcc/config/xtensa/xtensa.c
@@ -79,11 +79,6 @@ enum internal_test
can support a given mode. */
char xtensa_hard_regno_mode_ok[(int) MAX_MACHINE_MODE][FIRST_PSEUDO_REGISTER];
-/* Current frame size calculated by compute_frame_size. */
-unsigned xtensa_current_frame_size;
-/* Callee-save area size in the current frame calculated by compute_frame_size. */
-int xtensa_callee_save_size;
-
/* Largest block move to handle in-line. */
#define LARGEST_MOVE_RATIO 15
@@ -95,6 +90,13 @@ struct GTY(()) machine_function
bool vararg_a7;
rtx vararg_a7_copy;
rtx_insn *set_frame_ptr_insn;
+ /* Current frame size calculated by compute_frame_size. */
+ unsigned current_frame_size;
+ /* Callee-save area size in the current frame calculated by
+ compute_frame_size. */
+ int callee_save_size;
+ bool frame_laid_out;
+ bool epilogue_done;
};
/* Vector, indexed by hard register number, which contains 1 for a
@@ -2632,24 +2634,29 @@ compute_frame_size (int size)
{
int regno;
+ if (reload_completed && cfun->machine->frame_laid_out)
+ return cfun->machine->current_frame_size;
+
/* Add space for the incoming static chain value. */
if (cfun->static_chain_decl != NULL)
size += (1 * UNITS_PER_WORD);
- xtensa_callee_save_size = 0;
+ cfun->machine->callee_save_size = 0;
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; ++regno)
{
if (xtensa_call_save_reg(regno))
- xtensa_callee_save_size += UNITS_PER_WORD;
+ cfun->machine->callee_save_size += UNITS_PER_WORD;
}
- xtensa_current_frame_size =
+ cfun->machine->current_frame_size =
XTENSA_STACK_ALIGN (size
- + xtensa_callee_save_size
+ + cfun->machine->callee_save_size
+ crtl->outgoing_args_size
+ (WINDOW_SIZE * UNITS_PER_WORD));
- xtensa_callee_save_size = XTENSA_STACK_ALIGN (xtensa_callee_save_size);
- return xtensa_current_frame_size;
+ cfun->machine->callee_save_size =
+ XTENSA_STACK_ALIGN (cfun->machine->callee_save_size);
+ cfun->machine->frame_laid_out = true;
+ return cfun->machine->current_frame_size;
}
@@ -2703,6 +2710,7 @@ xtensa_expand_prologue (void)
{
int regno;
HOST_WIDE_INT offset = 0;
+ int callee_save_size = cfun->machine->callee_save_size;
/* -128 is a limit of single addi instruction. */
if (total_size > 0 && total_size <= 128)
@@ -2716,7 +2724,7 @@ xtensa_expand_prologue (void)
add_reg_note (insn, REG_FRAME_RELATED_EXPR, note_rtx);
offset = total_size - UNITS_PER_WORD;
}
- else if (xtensa_callee_save_size)
+ else if (callee_save_size)
{
/* 1020 is maximal s32i offset, if the frame is bigger than that
* we move sp to the end of callee-saved save area, save and then
@@ -2724,13 +2732,13 @@ xtensa_expand_prologue (void)
if (total_size > 1024)
{
insn = emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
- GEN_INT (-xtensa_callee_save_size)));
+ GEN_INT (-callee_save_size)));
RTX_FRAME_RELATED_P (insn) = 1;
note_rtx = gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- -xtensa_callee_save_size));
+ -callee_save_size));
add_reg_note (insn, REG_FRAME_RELATED_EXPR, note_rtx);
- offset = xtensa_callee_save_size - UNITS_PER_WORD;
+ offset = callee_save_size - UNITS_PER_WORD;
}
else
{
@@ -2766,13 +2774,13 @@ xtensa_expand_prologue (void)
{
rtx tmp_reg = gen_rtx_REG (Pmode, A9_REG);
emit_move_insn (tmp_reg, GEN_INT (total_size -
- xtensa_callee_save_size));
+ callee_save_size));
insn = emit_insn (gen_subsi3 (stack_pointer_rtx,
stack_pointer_rtx, tmp_reg));
RTX_FRAME_RELATED_P (insn) = 1;
note_rtx = gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- xtensa_callee_save_size -
+ callee_save_size -
total_size));
add_reg_note (insn, REG_FRAME_RELATED_EXPR, note_rtx);
}
@@ -2840,21 +2848,21 @@ xtensa_expand_epilogue (void)
int regno;
HOST_WIDE_INT offset;
- if (xtensa_current_frame_size > (frame_pointer_needed ? 127 : 1024))
+ if (cfun->machine->current_frame_size > (frame_pointer_needed ? 127 : 1024))
{
rtx tmp_reg = gen_rtx_REG (Pmode, A9_REG);
- emit_move_insn (tmp_reg, GEN_INT (xtensa_current_frame_size -
- xtensa_callee_save_size));
+ emit_move_insn (tmp_reg, GEN_INT (cfun->machine->current_frame_size -
+ cfun->machine->callee_save_size));
emit_insn (gen_addsi3 (stack_pointer_rtx, frame_pointer_needed ?
hard_frame_pointer_rtx : stack_pointer_rtx,
tmp_reg));
- offset = xtensa_callee_save_size - UNITS_PER_WORD;
+ offset = cfun->machine->callee_save_size - UNITS_PER_WORD;
}
else
{
if (frame_pointer_needed)
emit_move_insn (stack_pointer_rtx, hard_frame_pointer_rtx);
- offset = xtensa_current_frame_size - UNITS_PER_WORD;
+ offset = cfun->machine->current_frame_size - UNITS_PER_WORD;
}
/* Prevent reordering of saved a0 update and loading it back from
@@ -2874,16 +2882,16 @@ xtensa_expand_epilogue (void)
}
}
- if (xtensa_current_frame_size > 0)
+ if (cfun->machine->current_frame_size > 0)
{
if (frame_pointer_needed || /* always reachable with addi */
- xtensa_current_frame_size > 1024 ||
- xtensa_current_frame_size <= 127)
+ cfun->machine->current_frame_size > 1024 ||
+ cfun->machine->current_frame_size <= 127)
{
- if (xtensa_current_frame_size <= 127)
- offset = xtensa_current_frame_size;
+ if (cfun->machine->current_frame_size <= 127)
+ offset = cfun->machine->current_frame_size;
else
- offset = xtensa_callee_save_size;
+ offset = cfun->machine->callee_save_size;
emit_insn (gen_addsi3 (stack_pointer_rtx,
stack_pointer_rtx,
@@ -2892,7 +2900,8 @@ xtensa_expand_epilogue (void)
else
{
rtx tmp_reg = gen_rtx_REG (Pmode, A9_REG);
- emit_move_insn (tmp_reg, GEN_INT (xtensa_current_frame_size));
+ emit_move_insn (tmp_reg,
+ GEN_INT (cfun->machine->current_frame_size));
emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
tmp_reg));
}
@@ -2903,11 +2912,22 @@ xtensa_expand_epilogue (void)
stack_pointer_rtx,
EH_RETURN_STACKADJ_RTX));
}
- xtensa_current_frame_size = 0;
- xtensa_callee_save_size = 0;
+ cfun->machine->epilogue_done = true;
emit_jump_insn (gen_return ());
}
+bool
+xtensa_use_return_instruction_p (void)
+{
+ if (!reload_completed)
+ return false;
+ if (TARGET_WINDOWED_ABI)
+ return true;
+ if (compute_frame_size (get_frame_size ()) == 0)
+ return true;
+ return cfun->machine->epilogue_done;
+}
+
void
xtensa_set_return_address (rtx address, rtx scratch)
{
diff --git a/gcc/config/xtensa/xtensa.h b/gcc/config/xtensa/xtensa.h
index 82e9900..58eb1b2 100644
--- a/gcc/config/xtensa/xtensa.h
+++ b/gcc/config/xtensa/xtensa.h
@@ -23,8 +23,6 @@ along with GCC; see the file COPYING3. If not see
/* External variables defined in xtensa.c. */
-extern unsigned xtensa_current_frame_size;
-
/* Macros used in the machine description to select various Xtensa
configuration options. */
#ifndef XCHAL_HAVE_MUL32_HIGH
@@ -477,14 +475,14 @@ enum reg_class
/* Specify the initial difference between the specified pair of registers. */
#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
do { \
- compute_frame_size (get_frame_size ()); \
+ long frame_size = compute_frame_size (get_frame_size ()); \
switch (FROM) \
{ \
case FRAME_POINTER_REGNUM: \
(OFFSET) = 0; \
break; \
case ARG_POINTER_REGNUM: \
- (OFFSET) = xtensa_current_frame_size; \
+ (OFFSET) = frame_size; \
break; \
default: \
gcc_unreachable (); \
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index db54a12..fcdb6c8 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -1663,7 +1663,7 @@
(define_insn "return"
[(return)
(use (reg:SI A0_REG))]
- "(TARGET_WINDOWED_ABI || !xtensa_current_frame_size) && reload_completed"
+ "xtensa_use_return_instruction_p ()"
{
return TARGET_WINDOWED_ABI ?
(TARGET_DENSITY ? "retw.n" : "retw") :
--
2.1.4
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] xtensa: Fix PR target/78118
2016-11-01 6:33 [PATCH] xtensa: Fix PR target/78118 Max Filippov
@ 2016-11-01 16:28 ` augustine.sterling
2016-11-01 17:18 ` Max Filippov
0 siblings, 1 reply; 3+ messages in thread
From: augustine.sterling @ 2016-11-01 16:28 UTC (permalink / raw)
To: Max Filippov; +Cc: gcc-patches, linux-xtensa
On Mon, Oct 31, 2016 at 11:32 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> 2016-10-26 Max Filippov <jcmvbkbc@gmail.com>
> gcc/
> * config/xtensa/xtensa-protos.h
> (xtensa_use_return_instruction_p): New prototype.
> * config/xtensa/xtensa.c (xtensa_current_frame_size,
> xtensa_callee_save_size): Remove.
> (struct machine_function): Add new fields: current_frame_size,
> callee_save_size, frame_laid_out and epilogue_done.
> (compute_frame_size, xtensa_expand_prologue,
> xtensa_expand_epilogue): Replace xtensa_callee_save_size with
> cfun->machine->callee_save_size and xtensa_current_frame_size
> with cfun->machine->current_frame_size.
> (compute_frame_size): Update cfun->machine->frame_laid_out and
> don't update frame layout after reload completion.
> (xtensa_expand_epilogue): Set cfun->machine->epilogue_done
> instead of zeroing xtensa_current_frame_size.
> (xtensa_use_return_instruction_p): New function.
> * config/xtensa/xtensa.h (xtensa_current_frame_size): Remove
> declaration.
> (INITIAL_ELIMINATION_OFFSET): Use return value of
> compute_frame_size instead of xtensa_current_frame_size value.
> * config/xtensa/xtensa.md ("return" pattern): Use new predicate
> function xtensa_use_return_instruction_p instead of inline code.
Approved. Please apply.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] xtensa: Fix PR target/78118
2016-11-01 16:28 ` augustine.sterling
@ 2016-11-01 17:18 ` Max Filippov
0 siblings, 0 replies; 3+ messages in thread
From: Max Filippov @ 2016-11-01 17:18 UTC (permalink / raw)
To: augustine.sterling; +Cc: gcc-patches, linux-xtensa
On Tue, Nov 1, 2016 at 9:28 AM, augustine.sterling@gmail.com
<augustine.sterling@gmail.com> wrote:
> On Mon, Oct 31, 2016 at 11:32 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
>> 2016-10-26 Max Filippov <jcmvbkbc@gmail.com>
>> gcc/
>> * config/xtensa/xtensa-protos.h
>> (xtensa_use_return_instruction_p): New prototype.
>> * config/xtensa/xtensa.c (xtensa_current_frame_size,
>> xtensa_callee_save_size): Remove.
>> (struct machine_function): Add new fields: current_frame_size,
>> callee_save_size, frame_laid_out and epilogue_done.
>> (compute_frame_size, xtensa_expand_prologue,
>> xtensa_expand_epilogue): Replace xtensa_callee_save_size with
>> cfun->machine->callee_save_size and xtensa_current_frame_size
>> with cfun->machine->current_frame_size.
>> (compute_frame_size): Update cfun->machine->frame_laid_out and
>> don't update frame layout after reload completion.
>> (xtensa_expand_epilogue): Set cfun->machine->epilogue_done
>> instead of zeroing xtensa_current_frame_size.
>> (xtensa_use_return_instruction_p): New function.
>> * config/xtensa/xtensa.h (xtensa_current_frame_size): Remove
>> declaration.
>> (INITIAL_ELIMINATION_OFFSET): Use return value of
>> compute_frame_size instead of xtensa_current_frame_size value.
>> * config/xtensa/xtensa.md ("return" pattern): Use new predicate
>> function xtensa_use_return_instruction_p instead of inline code.
>
> Approved. Please apply.
Applied to trunk. Thank you!
-- Max
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-11-01 16:28 ` augustine.sterling
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