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[PATCH][AArch64] Optimize prolog/epilog
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: nd <nd at arm dot com>
- Date: Fri, 29 Jul 2016 11:49:00 +0000
- Subject: [PATCH][AArch64] Optimize prolog/epilog
- Authentication-results: sourceware.org; auth=none
- Nodisclaimer: True
- Spamdiagnosticmetadata: NSPM
- Spamdiagnosticoutput: 1:99
This patch optimizes the prolog and epilog code to reduce the number of
instructions and avoid multiple writes to SP. The key idea is that epilogs
are almost exact reverses of prologs, and thus all the decisions only need
to be taken once. The frame layout is decided in aarch64_layout_frame()
and decisions recorded in the new aarch64_frame fields initial_adjust,
callee_adjust, callee_offset and final_adjust.
A generic frame setup consists of 5 basic steps:
1. sub sp, sp, initial_adjust
2. stp reg1, reg2, [sp, -callee_adjust]! (push if callee_adjust != 0)
3. add fp, sp, callee_offset (if frame_pointer_needed)
4. stp reg3, reg4, [sp, callee_offset + N*16] (store remaining callee-saves)
5. sub sp, sp, final_adjust
The epilog reverses this, and may omit step 3 if alloca wasn't used.
Bootstrap, GCC & gdb regression OK.
ChangeLog:
2016-07-29 Wilco Dijkstra <wdijkstr@arm.com>
gcc/
* config/aarch64/aarch64.h (aarch64_frame):
Remove padding0 and hardfp_offset. Add locals_offset,
initial_adjust, callee_adjust, callee_offset and final_adjust.
* config/aarch64/aarch64.c (aarch64_layout_frame):
Remove unused padding0 and hardfp_offset initializations.
Choose frame layout and set frame variables accordingly.
Use INVALID_REGNUM instead of FIRST_PSEUDO_REGISTER.
(aarch64_push_regs): Use INVALID_REGNUM, not FIRST_PSEUDO_REGISTER.
(aarch64_pop_regs): Likewise.
(aarch64_expand_prologue): Remove all decision code, just emit
prolog according to frame variables.
(aarch64_expand_epilogue): Remove all decision code, just emit
epilog according to frame variables.
(aarch64_initial_elimination_offset): Use offset to local/arg area.
testsuite/
* gcc.target/aarch64/test_frame_10.c: Fix test to check for a
single stack adjustment, no writeback.
* gcc.target/aarch64/test_frame_12.c: Likewise.
* gcc.target/aarch64/test_frame_13.c: Likewise.
* gcc.target/aarch64/test_frame_15.c: Likewise.
* gcc.target/aarch64/test_frame_6.c: Likewise.
* gcc.target/aarch64/test_frame_7.c: Likewise.
* gcc.target/aarch64/test_frame_8.c: Likewise.
* gcc.target/aarch64/test_frame_16.c: New test.
---
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 58959229c004e58405076b0e691b6b5634720140..455869f074dd72a38b6f8e1b199d83aa75b408b1 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -550,11 +550,14 @@ struct GTY (()) aarch64_frame
STACK_BOUNDARY. */
HOST_WIDE_INT saved_varargs_size;
+ /* The size of the saved callee-save int/FP registers. */
+
HOST_WIDE_INT saved_regs_size;
- /* Padding if needed after the all the callee save registers have
- been saved. */
- HOST_WIDE_INT padding0;
- HOST_WIDE_INT hardfp_offset; /* HARD_FRAME_POINTER_REGNUM */
+
+ /* Offset from the base of the frame (incomming SP) to the
+ top of the locals area. This value is always a multiple of
+ STACK_BOUNDARY. */
+ HOST_WIDE_INT locals_offset;
/* Offset from the base of the frame (incomming SP) to the
hard_frame_pointer. This value is always a multiple of
@@ -564,12 +567,25 @@ struct GTY (()) aarch64_frame
/* The size of the frame. This value is the offset from base of the
* frame (incomming SP) to the stack_pointer. This value is always
* a multiple of STACK_BOUNDARY. */
+ HOST_WIDE_INT frame_size;
+
+ /* The size of the initial stack adjustment before saving callee-saves. */
+ HOST_WIDE_INT initial_adjust;
+
+ /* The writeback value when pushing callee-save registers.
+ It is zero when no push is used. */
+ HOST_WIDE_INT callee_adjust;
+
+ /* The offset from SP to the callee-save registers after initial_adjust.
+ It may be non-zero if no push is used (ie. callee_adjust == 0). */
+ HOST_WIDE_INT callee_offset;
+
+ /* The size of the stack adjustment after saving callee-saves. */
+ HOST_WIDE_INT final_adjust;
unsigned wb_candidate1;
unsigned wb_candidate2;
- HOST_WIDE_INT frame_size;
-
bool laid_out;
};
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 2023cb45fc8e87d94b48ae894bea78235056d4a4..7179dac29736409e1679e4bc932b95ba4c9aa1a5 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -2728,8 +2728,8 @@ aarch64_layout_frame (void)
#define SLOT_NOT_REQUIRED (-2)
#define SLOT_REQUIRED (-1)
- cfun->machine->frame.wb_candidate1 = FIRST_PSEUDO_REGISTER;
- cfun->machine->frame.wb_candidate2 = FIRST_PSEUDO_REGISTER;
+ cfun->machine->frame.wb_candidate1 = INVALID_REGNUM;
+ cfun->machine->frame.wb_candidate2 = INVALID_REGNUM;
/* First mark all the registers that really need to be saved... */
for (regno = R0_REGNUM; regno <= R30_REGNUM; regno++)
@@ -2763,7 +2763,6 @@ aarch64_layout_frame (void)
cfun->machine->frame.wb_candidate1 = R29_REGNUM;
cfun->machine->frame.reg_offset[R30_REGNUM] = UNITS_PER_WORD;
cfun->machine->frame.wb_candidate2 = R30_REGNUM;
- cfun->machine->frame.hardfp_offset = 2 * UNITS_PER_WORD;
offset += 2 * UNITS_PER_WORD;
}
@@ -2772,9 +2771,9 @@ aarch64_layout_frame (void)
if (cfun->machine->frame.reg_offset[regno] == SLOT_REQUIRED)
{
cfun->machine->frame.reg_offset[regno] = offset;
- if (cfun->machine->frame.wb_candidate1 == FIRST_PSEUDO_REGISTER)
+ if (cfun->machine->frame.wb_candidate1 == INVALID_REGNUM)
cfun->machine->frame.wb_candidate1 = regno;
- else if (cfun->machine->frame.wb_candidate2 == FIRST_PSEUDO_REGISTER)
+ else if (cfun->machine->frame.wb_candidate2 == INVALID_REGNUM)
cfun->machine->frame.wb_candidate2 = regno;
offset += UNITS_PER_WORD;
}
@@ -2783,24 +2782,23 @@ aarch64_layout_frame (void)
if (cfun->machine->frame.reg_offset[regno] == SLOT_REQUIRED)
{
cfun->machine->frame.reg_offset[regno] = offset;
- if (cfun->machine->frame.wb_candidate1 == FIRST_PSEUDO_REGISTER)
+ if (cfun->machine->frame.wb_candidate1 == INVALID_REGNUM)
cfun->machine->frame.wb_candidate1 = regno;
- else if (cfun->machine->frame.wb_candidate2 == FIRST_PSEUDO_REGISTER
+ else if (cfun->machine->frame.wb_candidate2 == INVALID_REGNUM
&& cfun->machine->frame.wb_candidate1 >= V0_REGNUM)
cfun->machine->frame.wb_candidate2 = regno;
offset += UNITS_PER_WORD;
}
- cfun->machine->frame.padding0 =
- (ROUND_UP (offset, STACK_BOUNDARY / BITS_PER_UNIT) - offset);
offset = ROUND_UP (offset, STACK_BOUNDARY / BITS_PER_UNIT);
cfun->machine->frame.saved_regs_size = offset;
+ HOST_WIDE_INT varargs_and_saved_regs_size = offset
+ + cfun->machine->frame.saved_varargs_size;
+
cfun->machine->frame.hard_fp_offset
- = ROUND_UP (cfun->machine->frame.saved_varargs_size
- + get_frame_size ()
- + cfun->machine->frame.saved_regs_size,
+ = ROUND_UP (varargs_and_saved_regs_size + get_frame_size (),
STACK_BOUNDARY / BITS_PER_UNIT);
cfun->machine->frame.frame_size
@@ -2808,6 +2806,77 @@ aarch64_layout_frame (void)
+ crtl->outgoing_args_size,
STACK_BOUNDARY / BITS_PER_UNIT);
+ cfun->machine->frame.locals_offset = cfun->machine->frame.saved_varargs_size;
+
+ cfun->machine->frame.initial_adjust = 0;
+ cfun->machine->frame.final_adjust = 0;
+ cfun->machine->frame.callee_adjust = 0;
+ cfun->machine->frame.callee_offset = 0;
+
+ HOST_WIDE_INT max_push_offset = 0;
+ if (cfun->machine->frame.wb_candidate2 != INVALID_REGNUM)
+ max_push_offset = 512;
+ else if (cfun->machine->frame.wb_candidate1 != INVALID_REGNUM)
+ max_push_offset = 256;
+
+ if (cfun->machine->frame.frame_size < max_push_offset
+ && crtl->outgoing_args_size == 0)
+ {
+ /* Simple, small frame with no outgoing arguments:
+ stp reg1, reg2, [sp, -frame_size]!
+ stp reg3, reg4, [sp, 16] */
+ cfun->machine->frame.callee_adjust = cfun->machine->frame.frame_size;
+ }
+ else if (crtl->outgoing_args_size
+ + cfun->machine->frame.saved_regs_size < 512
+ && !(cfun->calls_alloca
+ && cfun->machine->frame.hard_fp_offset < max_push_offset))
+ {
+ /* Frame with small outgoing arguments:
+ sub sp, sp, frame_size
+ stp reg1, reg2, [sp, outgoing_args_size]
+ stp reg3, reg4, [sp, outgoing_args_size + 16] */
+ cfun->machine->frame.initial_adjust = cfun->machine->frame.frame_size;
+ cfun->machine->frame.callee_offset
+ = cfun->machine->frame.frame_size - cfun->machine->frame.hard_fp_offset;
+ }
+ else if (cfun->machine->frame.hard_fp_offset < max_push_offset)
+ {
+ /* Frame with large outgoing arguments but a small local area:
+ stp reg1, reg2, [sp, -hard_fp_offset]!
+ stp reg3, reg4, [sp, 16]
+ sub sp, sp, outgoing_args_size */
+ cfun->machine->frame.callee_adjust = cfun->machine->frame.hard_fp_offset;
+ cfun->machine->frame.final_adjust
+ = cfun->machine->frame.frame_size - cfun->machine->frame.callee_adjust;
+ }
+ else if (!frame_pointer_needed
+ && varargs_and_saved_regs_size < max_push_offset)
+ {
+ /* Frame with large local area and outgoing arguments (this pushes the
+ callee-saves first, followed by the locals and outgoing area):
+ stp reg1, reg2, [sp, -varargs_and_saved_regs_size]!
+ stp reg3, reg4, [sp, 16]
+ sub sp, sp, frame_size - varargs_and_saved_regs_size */
+ cfun->machine->frame.callee_adjust = varargs_and_saved_regs_size;
+ cfun->machine->frame.final_adjust
+ = cfun->machine->frame.frame_size - cfun->machine->frame.callee_adjust;
+ cfun->machine->frame.hard_fp_offset = cfun->machine->frame.callee_adjust;
+ cfun->machine->frame.locals_offset = cfun->machine->frame.hard_fp_offset;
+ }
+ else
+ {
+ /* Frame with large local area and outgoing arguments using frame pointer:
+ sub sp, sp, hard_fp_offset
+ stp x29, x30, [sp, 0]
+ add x29, sp, 0
+ stp reg3, reg4, [sp, 16]
+ sub sp, sp, outgoing_args_size */
+ cfun->machine->frame.initial_adjust = cfun->machine->frame.hard_fp_offset;
+ cfun->machine->frame.final_adjust
+ = cfun->machine->frame.frame_size - cfun->machine->frame.initial_adjust;
+ }
+
cfun->machine->frame.laid_out = true;
}
@@ -2866,7 +2935,7 @@ aarch64_push_regs (unsigned regno1, unsigned regno2, HOST_WIDE_INT adjustment)
rtx_insn *insn;
machine_mode mode = (regno1 <= R30_REGNUM) ? DImode : DFmode;
- if (regno2 == FIRST_PSEUDO_REGISTER)
+ if (regno2 == INVALID_REGNUM)
return aarch64_pushwb_single_reg (mode, regno1, adjustment);
rtx reg1 = gen_rtx_REG (mode, regno1);
@@ -2905,7 +2974,7 @@ aarch64_pop_regs (unsigned regno1, unsigned regno2, HOST_WIDE_INT adjustment,
*cfi_ops = alloc_reg_note (REG_CFA_RESTORE, reg1, *cfi_ops);
- if (regno2 == FIRST_PSEUDO_REGISTER)
+ if (regno2 == INVALID_REGNUM)
{
rtx mem = plus_constant (Pmode, stack_pointer_rtx, adjustment);
mem = gen_rtx_POST_MODIFY (Pmode, stack_pointer_rtx, mem);
@@ -3106,23 +3175,16 @@ aarch64_restore_callee_saves (machine_mode mode,
void
aarch64_expand_prologue (void)
{
- /* sub sp, sp, #<frame_size>
- stp {fp, lr}, [sp, #<frame_size> - 16]
- add fp, sp, #<frame_size> - hardfp_offset
- stp {cs_reg}, [fp, #-16] etc.
-
- sub sp, sp, <final_adjustment_if_any>
- */
- HOST_WIDE_INT frame_size, offset;
- HOST_WIDE_INT fp_offset; /* Offset from hard FP to SP. */
- HOST_WIDE_INT hard_fp_offset;
- rtx_insn *insn;
-
aarch64_layout_frame ();
- offset = frame_size = cfun->machine->frame.frame_size;
- hard_fp_offset = cfun->machine->frame.hard_fp_offset;
- fp_offset = frame_size - hard_fp_offset;
+ HOST_WIDE_INT frame_size = cfun->machine->frame.frame_size;
+ HOST_WIDE_INT initial_adjust = cfun->machine->frame.initial_adjust;
+ HOST_WIDE_INT callee_adjust = cfun->machine->frame.callee_adjust;
+ HOST_WIDE_INT final_adjust = cfun->machine->frame.final_adjust;
+ HOST_WIDE_INT callee_offset = cfun->machine->frame.callee_offset;
+ unsigned reg1 = cfun->machine->frame.wb_candidate1;
+ unsigned reg2 = cfun->machine->frame.wb_candidate2;
+ rtx_insn *insn;
if (flag_stack_usage_info)
current_function_static_stack_size = frame_size;
@@ -3139,94 +3201,29 @@ aarch64_expand_prologue (void)
aarch64_emit_probe_stack_range (STACK_CHECK_PROTECT, frame_size);
}
- /* Store pairs and load pairs have a range only -512 to 504. */
- if (offset >= 512)
- {
- /* When the frame has a large size, an initial decrease is done on
- the stack pointer to jump over the callee-allocated save area for
- register varargs, the local variable area and/or the callee-saved
- register area. This will allow the pre-index write-back
- store pair instructions to be used for setting up the stack frame
- efficiently. */
- offset = hard_fp_offset;
- if (offset >= 512)
- offset = cfun->machine->frame.saved_regs_size;
-
- frame_size -= (offset + crtl->outgoing_args_size);
- fp_offset = 0;
+ aarch64_add_constant (Pmode, SP_REGNUM, IP0_REGNUM, -initial_adjust, true);
- aarch64_add_constant (Pmode, SP_REGNUM, IP0_REGNUM, -frame_size, true);
- }
- else
- frame_size = -1;
+ if (callee_adjust != 0)
+ aarch64_push_regs (reg1, reg2, callee_adjust);
- if (offset > 0)
+ if (frame_pointer_needed)
{
- bool skip_wb = false;
-
- if (frame_pointer_needed)
- {
- skip_wb = true;
-
- if (fp_offset)
- {
- insn = emit_insn (gen_add2_insn (stack_pointer_rtx,
- GEN_INT (-offset)));
- RTX_FRAME_RELATED_P (insn) = 1;
-
- aarch64_save_callee_saves (DImode, fp_offset, R29_REGNUM,
- R30_REGNUM, false);
- }
- else
- aarch64_push_regs (R29_REGNUM, R30_REGNUM, offset);
-
- /* Set up frame pointer to point to the location of the
- previous frame pointer on the stack. */
- insn = emit_insn (gen_add3_insn (hard_frame_pointer_rtx,
- stack_pointer_rtx,
- GEN_INT (fp_offset)));
- RTX_FRAME_RELATED_P (insn) = 1;
- emit_insn (gen_stack_tie (stack_pointer_rtx, hard_frame_pointer_rtx));
- }
- else
- {
- unsigned reg1 = cfun->machine->frame.wb_candidate1;
- unsigned reg2 = cfun->machine->frame.wb_candidate2;
-
- if (fp_offset
- || reg1 == FIRST_PSEUDO_REGISTER
- || (reg2 == FIRST_PSEUDO_REGISTER
- && offset >= 256))
- {
- insn = emit_insn (gen_add2_insn (stack_pointer_rtx,
- GEN_INT (-offset)));
- RTX_FRAME_RELATED_P (insn) = 1;
- }
- else
- {
- aarch64_push_regs (reg1, reg2, offset);
- skip_wb = true;
- }
- }
-
- aarch64_save_callee_saves (DImode, fp_offset, R0_REGNUM, R30_REGNUM,
- skip_wb);
- aarch64_save_callee_saves (DFmode, fp_offset, V0_REGNUM, V31_REGNUM,
- skip_wb);
+ if (callee_adjust == 0)
+ aarch64_save_callee_saves (DImode, callee_offset, R29_REGNUM,
+ R30_REGNUM, false);
+ insn = emit_insn (gen_add3_insn (hard_frame_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (callee_offset)));
+ RTX_FRAME_RELATED_P (insn) = 1;
+ emit_insn (gen_stack_tie (stack_pointer_rtx, hard_frame_pointer_rtx));
}
- /* when offset >= 512,
- sub sp, sp, #<outgoing_args_size> */
- if (frame_size > -1)
- {
- if (crtl->outgoing_args_size > 0)
- {
- insn = emit_insn (gen_add2_insn
- (stack_pointer_rtx,
- GEN_INT (- crtl->outgoing_args_size)));
- RTX_FRAME_RELATED_P (insn) = 1;
- }
- }
+ aarch64_save_callee_saves (DImode, callee_offset, R0_REGNUM, R30_REGNUM,
+ callee_adjust != 0 || frame_pointer_needed);
+ aarch64_save_callee_saves (DFmode, callee_offset, V0_REGNUM, V31_REGNUM,
+ callee_adjust != 0 || frame_pointer_needed);
+ aarch64_add_constant (Pmode, SP_REGNUM, IP1_REGNUM, -final_adjust,
+ !frame_pointer_needed);
}
/* Return TRUE if we can use a simple_return insn.
@@ -3249,104 +3246,80 @@ aarch64_use_return_insn_p (void)
return cfun->machine->frame.frame_size == 0;
}
-/* Generate the epilogue instructions for returning from a function. */
+/* Generate the epilogue instructions for returning from a function.
+ This is almost exactly the reverse of the prolog sequence, except
+ that we need to insert barriers to avoid scheduling loads that read
+ from a deallocated stack, and we optimize the unwind records by
+ emitting them all together if possible. */
void
aarch64_expand_epilogue (bool for_sibcall)
{
- HOST_WIDE_INT frame_size, offset;
- HOST_WIDE_INT fp_offset;
- HOST_WIDE_INT hard_fp_offset;
- rtx_insn *insn;
- /* We need to add memory barrier to prevent read from deallocated stack. */
- bool need_barrier_p = (get_frame_size () != 0
- || cfun->machine->frame.saved_varargs_size);
-
aarch64_layout_frame ();
- offset = frame_size = cfun->machine->frame.frame_size;
- hard_fp_offset = cfun->machine->frame.hard_fp_offset;
- fp_offset = frame_size - hard_fp_offset;
+ HOST_WIDE_INT initial_adjust = cfun->machine->frame.initial_adjust;
+ HOST_WIDE_INT callee_adjust = cfun->machine->frame.callee_adjust;
+ HOST_WIDE_INT final_adjust = cfun->machine->frame.final_adjust;
+ HOST_WIDE_INT callee_offset = cfun->machine->frame.callee_offset;
+ unsigned reg1 = cfun->machine->frame.wb_candidate1;
+ unsigned reg2 = cfun->machine->frame.wb_candidate2;
+ rtx cfi_ops = NULL;
+ rtx_insn *insn;
- /* Store pairs and load pairs have a range only -512 to 504. */
- if (offset >= 512)
- {
- offset = hard_fp_offset;
- if (offset >= 512)
- offset = cfun->machine->frame.saved_regs_size;
+ /* We need to add memory barrier to prevent read from deallocated stack. */
+ bool need_barrier_p = (get_frame_size ()
+ + cfun->machine->frame.saved_varargs_size) != 0;
- frame_size -= (offset + crtl->outgoing_args_size);
- fp_offset = 0;
- if (!frame_pointer_needed && crtl->outgoing_args_size > 0)
- {
- insn = emit_insn (gen_add2_insn
- (stack_pointer_rtx,
- GEN_INT (crtl->outgoing_args_size)));
- RTX_FRAME_RELATED_P (insn) = 1;
- }
+ /* Emit a barrier to prevent loads from a deallocated stack. */
+ if (final_adjust > crtl->outgoing_args_size || cfun->calls_alloca)
+ {
+ emit_insn (gen_stack_tie (stack_pointer_rtx, stack_pointer_rtx));
+ need_barrier_p = false;
}
- else
- frame_size = -1;
- /* If there were outgoing arguments or we've done dynamic stack
- allocation, then restore the stack pointer from the frame
- pointer. This is at most one insn and more efficient than using
- GCC's internal mechanism. */
- if (frame_pointer_needed
- && (crtl->outgoing_args_size || cfun->calls_alloca))
+ /* Restore the stack pointer from the frame pointer if it may not
+ be the same as the stack pointer. */
+ if (frame_pointer_needed && (final_adjust || cfun->calls_alloca))
{
- if (cfun->calls_alloca)
- emit_insn (gen_stack_tie (stack_pointer_rtx, stack_pointer_rtx));
-
insn = emit_insn (gen_add3_insn (stack_pointer_rtx,
hard_frame_pointer_rtx,
- GEN_INT (0)));
- offset = offset - fp_offset;
+ GEN_INT (-callee_offset)));
+ /* If writeback is used when restoring callee-saves, the CFA
+ is restored on the instruction doing the writeback. */
+ RTX_FRAME_RELATED_P (insn) = callee_adjust == 0;
}
+ else
+ aarch64_add_constant (Pmode, SP_REGNUM, IP1_REGNUM, final_adjust, true);
- if (offset > 0)
- {
- unsigned reg1 = cfun->machine->frame.wb_candidate1;
- unsigned reg2 = cfun->machine->frame.wb_candidate2;
- bool skip_wb = true;
- rtx cfi_ops = NULL;
-
- if (frame_pointer_needed)
- fp_offset = 0;
- else if (fp_offset
- || reg1 == FIRST_PSEUDO_REGISTER
- || (reg2 == FIRST_PSEUDO_REGISTER
- && offset >= 256))
- skip_wb = false;
-
- aarch64_restore_callee_saves (DImode, fp_offset, R0_REGNUM, R30_REGNUM,
- skip_wb, &cfi_ops);
- aarch64_restore_callee_saves (DFmode, fp_offset, V0_REGNUM, V31_REGNUM,
- skip_wb, &cfi_ops);
+ aarch64_restore_callee_saves (DImode, callee_offset, R0_REGNUM, R30_REGNUM,
+ callee_adjust != 0, &cfi_ops);
+ aarch64_restore_callee_saves (DFmode, callee_offset, V0_REGNUM, V31_REGNUM,
+ callee_adjust != 0, &cfi_ops);
- if (need_barrier_p)
- emit_insn (gen_stack_tie (stack_pointer_rtx, stack_pointer_rtx));
+ if (need_barrier_p)
+ emit_insn (gen_stack_tie (stack_pointer_rtx, stack_pointer_rtx));
- if (skip_wb)
- aarch64_pop_regs (reg1, reg2, offset, &cfi_ops);
- else
- emit_insn (gen_add2_insn (stack_pointer_rtx, GEN_INT (offset)));
+ if (callee_adjust != 0)
+ aarch64_pop_regs (reg1, reg2, callee_adjust, &cfi_ops);
- /* Reset the CFA to be SP + FRAME_SIZE. */
- rtx new_cfa = stack_pointer_rtx;
- if (frame_size > 0)
- new_cfa = plus_constant (Pmode, new_cfa, frame_size);
- cfi_ops = alloc_reg_note (REG_CFA_DEF_CFA, new_cfa, cfi_ops);
+ if (callee_adjust != 0 || initial_adjust > 65536)
+ {
+ /* Emit delayed restores and set the CFA to be SP + initial_adjust. */
insn = get_last_insn ();
- REG_NOTES (insn) = cfi_ops;
+ rtx new_cfa = plus_constant (Pmode, stack_pointer_rtx, initial_adjust);
+ REG_NOTES (insn) = alloc_reg_note (REG_CFA_DEF_CFA, new_cfa, cfi_ops);
RTX_FRAME_RELATED_P (insn) = 1;
+ cfi_ops = NULL;
}
- if (frame_size > 0)
- {
- if (need_barrier_p)
- emit_insn (gen_stack_tie (stack_pointer_rtx, stack_pointer_rtx));
+ aarch64_add_constant (Pmode, SP_REGNUM, IP0_REGNUM, initial_adjust, true);
- aarch64_add_constant (Pmode, SP_REGNUM, IP0_REGNUM, frame_size, true);
+ if (cfi_ops)
+ {
+ /* Emit delayed restores and reset the CFA to be SP. */
+ insn = get_last_insn ();
+ cfi_ops = alloc_reg_note (REG_CFA_DEF_CFA, stack_pointer_rtx, cfi_ops);
+ REG_NOTES (insn) = cfi_ops;
+ RTX_FRAME_RELATED_P (insn) = 1;
}
/* Stack adjustment for exception handler. */
@@ -5173,18 +5146,18 @@ aarch64_initial_elimination_offset (unsigned from, unsigned to)
if (to == HARD_FRAME_POINTER_REGNUM)
{
if (from == ARG_POINTER_REGNUM)
- return cfun->machine->frame.frame_size - crtl->outgoing_args_size;
+ return cfun->machine->frame.hard_fp_offset;
if (from == FRAME_POINTER_REGNUM)
- return (cfun->machine->frame.hard_fp_offset
- - cfun->machine->frame.saved_varargs_size);
+ return cfun->machine->frame.hard_fp_offset
+ - cfun->machine->frame.locals_offset;
}
if (to == STACK_POINTER_REGNUM)
{
if (from == FRAME_POINTER_REGNUM)
- return (cfun->machine->frame.frame_size
- - cfun->machine->frame.saved_varargs_size);
+ return cfun->machine->frame.frame_size
+ - cfun->machine->frame.locals_offset;
}
return cfun->machine->frame.frame_size;
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_10.c b/gcc/testsuite/gcc.target/aarch64/test_frame_10.c
index 70dd6539af93a034ae64f8603089c6d6f59a6b53..e23a4a83528b71a0de0c95752a9e530bf4ca79e5 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_10.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_10.c
@@ -4,8 +4,7 @@
* total frame size > 512.
area except outgoing <= 512
* number of callee-saved reg >= 2.
- * Split stack adjustment into two subtractions.
- the first subtractions could be optimized into "stp !". */
+ * Use a single stack adjustment, no writeback. */
/* { dg-do run } */
/* { dg-options "-O2 -fomit-frame-pointer --save-temps" } */
@@ -15,6 +14,6 @@
t_frame_pattern_outgoing (test10, 480, "x19", 24, a[8], a[9], a[10])
t_frame_run (test10)
-/* { dg-final { scan-assembler-times "stp\tx19, x30, \\\[sp, -\[0-9\]+\\\]!" 1 } } */
-/* { dg-final { scan-assembler-times "ldp\tx19, x30, \\\[sp\\\], \[0-9\]+" 1 } } */
+/* { dg-final { scan-assembler-times "stp\tx19, x30, \\\[sp, \[0-9\]+\\\]" 1 } } */
+/* { dg-final { scan-assembler-times "ldp\tx19, x30, \\\[sp, \[0-9\]+\\\]" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_12.c b/gcc/testsuite/gcc.target/aarch64/test_frame_12.c
index 2353477c29ea99c56e73a34cf0449cf6c669e973..3d7d3594610c645d2d6f449b6ee0400fdd395849 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_12.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_12.c
@@ -13,6 +13,6 @@ t_frame_run (test12)
/* { dg-final { scan-assembler-times "sub\tsp, sp, #\[0-9\]+" 1 } } */
-/* Check epilogue using write-back. */
-/* { dg-final { scan-assembler-times "ldp\tx29, x30, \\\[sp\\\], \[0-9\]+" 3 } } */
+/* Check epilogue using no write-back. */
+/* { dg-final { scan-assembler-times "ldp\tx29, x30, \\\[sp, \[0-9\]+\\\]" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_13.c b/gcc/testsuite/gcc.target/aarch64/test_frame_13.c
index f3aa263929421db12b78abc733e2b011db3a4e48..74b3370fa463b652265e00fff80cc8856524d509 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_13.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_13.c
@@ -2,8 +2,7 @@
* without outgoing.
* total frame size > 512.
* number of callee-save reg >= 2.
- * split the stack adjustment into two substractions,
- the second could be optimized into "stp !". */
+ * Use a single stack adjustment, no writeback. */
/* { dg-do run } */
/* { dg-options "-O2 --save-temps" } */
@@ -14,4 +13,4 @@ t_frame_pattern (test13, 700, )
t_frame_run (test13)
/* { dg-final { scan-assembler-times "sub\tsp, sp, #\[0-9\]+" 1 } } */
-/* { dg-final { scan-assembler-times "stp\tx29, x30, \\\[sp, -\[0-9\]+\\\]!" 2 } } */
+/* { dg-final { scan-assembler-times "stp\tx29, x30, \\\[sp\\\]" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_15.c b/gcc/testsuite/gcc.target/aarch64/test_frame_15.c
index fc6f713232de52b72ba5c3eef92e1aea6526199d..bed6714b4fe529a3b81ad8c5253924aa97bf8806 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_15.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_15.c
@@ -3,8 +3,7 @@
* total frame size > 512.
area except outgoing <= 512
* number of callee-save reg >= 2.
- * split the stack adjustment into two substractions,
- the first could be optimized into "stp !". */
+ * Use a single stack adjustment, no writeback. */
/* { dg-do run } */
/* { dg-options "-O2 --save-temps" } */
@@ -15,4 +14,4 @@ t_frame_pattern_outgoing (test15, 480, , 8, a[8])
t_frame_run (test15)
/* { dg-final { scan-assembler-times "sub\tsp, sp, #\[0-9\]+" 1 } } */
-/* { dg-final { scan-assembler-times "stp\tx29, x30, \\\[sp, -\[0-9\]+\\\]!" 3 } } */
+/* { dg-final { scan-assembler-times "stp\tx29, x30, \\\[sp, \[0-9\]+\\\]" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_16.c b/gcc/testsuite/gcc.target/aarch64/test_frame_16.c
new file mode 100644
index 0000000000000000000000000000000000000000..28f3826adadd5eaa6486659e4d6b6d7c5960b9d2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_16.c
@@ -0,0 +1,25 @@
+/* Verify:
+ * with outgoing.
+ * single int register push.
+ * varargs and callee-save size >= 256
+ * Use 2 stack adjustments. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -fomit-frame-pointer --save-temps" } */
+
+#define REP8(X) X,X,X,X,X,X,X,X
+#define REP64(X) REP8(REP8(X))
+
+void outgoing (__builtin_va_list, ...);
+
+double vararg_outgoing (int x1, ...)
+{
+ double a1 = x1, a2 = x1 * 2, a3 = x1 * 3, a4 = x1 * 4, a5 = x1 * 5, a6 = x1 * 6;
+ __builtin_va_list vl;
+ __builtin_va_start (vl, x1);
+ outgoing (vl, a1, a2, a3, a4, a5, a6, REP64 (1));
+ __builtin_va_end (vl);
+ return a1 + a2 + a3 + a4 + a5 + a6;
+}
+
+/* { dg-final { scan-assembler-times "sub\tsp, sp, #\[0-9\]+" 2 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_6.c b/gcc/testsuite/gcc.target/aarch64/test_frame_6.c
index d8481346c58458934deecb4b7f38fb5821517b56..6a753dff87e28fa71a2f69df5fb95559163fa6cd 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_6.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_6.c
@@ -3,8 +3,7 @@
* without outgoing.
* total frame size > 512.
* number of callee-saved reg == 1.
- * split stack adjustment into two subtractions.
- the second subtraction should use "str !". */
+ * use a single stack adjustment, no writeback. */
/* { dg-do run } */
/* { dg-options "-O2 -fomit-frame-pointer --save-temps" } */
@@ -14,6 +13,7 @@
t_frame_pattern (test6, 700, )
t_frame_run (test6)
-/* { dg-final { scan-assembler-times "str\tx30, \\\[sp, -\[0-9\]+\\\]!" 2 } } */
-/* { dg-final { scan-assembler-times "ldr\tx30, \\\[sp\\\], \[0-9\]+" 2 } } */
+/* { dg-final { scan-assembler-times "str\tx30, \\\[sp\\\]" 1 } } */
+/* { dg-final { scan-assembler-times "ldr\tx30, \\\[sp\\\]" 2 } } */
+/* { dg-final { scan-assembler-times "ldr\tx30, \\\[sp\\\]," 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_7.c b/gcc/testsuite/gcc.target/aarch64/test_frame_7.c
index d87d68b3eec72dd23b279ea94391a400c9ae5a9a..f2a8713d19d9f7df49073e9588c5d74661491fb6 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_7.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_7.c
@@ -3,8 +3,7 @@
* without outgoing.
* total frame size > 512.
* number of callee-saved reg == 2.
- * split stack adjustment into two subtractions.
- the second subtraction should use "stp !". */
+ * use a single stack adjustment, no writeback. */
/* { dg-do run } */
/* { dg-options "-O2 -fomit-frame-pointer --save-temps" } */
@@ -14,6 +13,6 @@
t_frame_pattern (test7, 700, "x19")
t_frame_run (test7)
-/* { dg-final { scan-assembler-times "stp\tx19, x30, \\\[sp, -\[0-9\]+\\\]!" 1 } } */
-/* { dg-final { scan-assembler-times "ldp\tx19, x30, \\\[sp\\\], \[0-9\]+" 1 } } */
+/* { dg-final { scan-assembler-times "stp\tx19, x30, \\\[sp]" 1 } } */
+/* { dg-final { scan-assembler-times "ldp\tx19, x30, \\\[sp\\\]" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/test_frame_8.c b/gcc/testsuite/gcc.target/aarch64/test_frame_8.c
index 435d9d59e68d71b1d4c56f1beca5fb1bce4f39b8..9b6c6939eb5c3ae1bdcab7fb854b6c519f054c20 100644
--- a/gcc/testsuite/gcc.target/aarch64/test_frame_8.c
+++ b/gcc/testsuite/gcc.target/aarch64/test_frame_8.c
@@ -12,6 +12,6 @@
t_frame_pattern_outgoing (test8, 700, , 8, a[8])
t_frame_run (test8)
-/* { dg-final { scan-assembler-times "str\tx30, \\\[sp, -\[0-9\]+\\\]!" 3 } } */
-/* { dg-final { scan-assembler-times "ldr\tx30, \\\[sp\\\], \[0-9\]+" 3 } } */
+/* { dg-final { scan-assembler-times "str\tx30, \\\[sp, \[0-9\]+\\\]" 1 } } */
+/* { dg-final { scan-assembler-times "ldr\tx30, \\\[sp, \[0-9\]+\\\]" 1 } } */