This implements the hooks for separate shrink-wrapping for rs6000.
It handles GPRs and LR. The GPRs get a concern number corresponding
to their register number; LR gets concern number 0.
This improves specint by 0.9%, specfp by 0.8%, some separate benchmarks
much more (on POWER8). It improves the hot path in various interpreters,
and e.g. in glibc's malloc.
2016-06-07 Segher Boessenkool <seg...@kernel.crashing.org>
* config/rs6000/rs6000.c (machine_function): Add new fields
gpr_is_wrapped_separately and lr_is_wrapped_separately.
(TARGET_SHRINK_WRAP_GET_SEPARATE_CONCERNS,
TARGET_SHRINK_WRAP_CONCERNS_FOR_BB,
TARGET_SHRINK_WRAP_DISQUALIFY_CONCERNS,
TARGET_SHRINK_WRAP_EMIT_PROLOGUE_CONCERNS,
TARGET_SHRINK_WRAP_EMIT_EPILOGUE_CONCERNS,
TARGET_SHRINK_WRAP_SET_HANDLED_CONCERNS): Define.
(rs6000_get_separate_concerns): New function.
(rs6000_concerns_for_bb): New function.
(rs6000_disqualify_concerns): New function.
(rs6000_emit_prologue_concerns): New function.
(rs6000_emit_epilogue_concerns): New function.
(rs6000_set_handled_concerns): New function.
(rs6000_emit_prologue): Don't emit LR save if lr_is_wrapped_separately.
Don't emit GPR saves if gpr_is_wrapped_separately for that register.
(restore_saved_lr): Don't restore LR if lr_is_wrapped_separately.
(rs6000_emit_epilogue): Don't emit GPR restores if
gpr_is_wrapped_separately for that register. Don't make a
REG_CFA_RESTORE note for registers we did not restore, either.
---
gcc/config/rs6000/rs6000.c | 257 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 242 insertions(+), 15 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index c6b2b6a..af56d8e 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -152,6 +152,10 @@ typedef struct GTY(()) machine_function
bool split_stack_argp_used;
/* Flag if r2 setup is needed with ELFv2 ABI. */
bool r2_setup_needed;
+ /* The concerns already handled by separate shrink-wrapping, which should
+ not be considered by the prologue and epilogue. */
+ bool gpr_is_wrapped_separately[32];
+ bool lr_is_wrapped_separately;
} machine_function;
/* Support targetm.vectorize.builtin_mask_for_load. */
@@ -1511,6 +1515,19 @@ static const struct attribute_spec
rs6000_attribute_table[] =
#undef TARGET_SET_UP_BY_PROLOGUE
#define TARGET_SET_UP_BY_PROLOGUE rs6000_set_up_by_prologue
+#undef TARGET_SHRINK_WRAP_GET_SEPARATE_CONCERNS
+#define TARGET_SHRINK_WRAP_GET_SEPARATE_CONCERNS rs6000_get_separate_concerns
+#undef TARGET_SHRINK_WRAP_CONCERNS_FOR_BB
+#define TARGET_SHRINK_WRAP_CONCERNS_FOR_BB rs6000_concerns_for_bb
+#undef TARGET_SHRINK_WRAP_DISQUALIFY_CONCERNS
+#define TARGET_SHRINK_WRAP_DISQUALIFY_CONCERNS rs6000_disqualify_concerns
+#undef TARGET_SHRINK_WRAP_EMIT_PROLOGUE_CONCERNS
+#define TARGET_SHRINK_WRAP_EMIT_PROLOGUE_CONCERNS rs6000_emit_prologue_concerns
+#undef TARGET_SHRINK_WRAP_EMIT_EPILOGUE_CONCERNS
+#define TARGET_SHRINK_WRAP_EMIT_EPILOGUE_CONCERNS rs6000_emit_epilogue_concerns
+#undef TARGET_SHRINK_WRAP_SET_HANDLED_CONCERNS
+#define TARGET_SHRINK_WRAP_SET_HANDLED_CONCERNS rs6000_set_handled_concerns
+
#undef TARGET_EXTRA_LIVE_ON_ENTRY
#define TARGET_EXTRA_LIVE_ON_ENTRY rs6000_live_on_entry
@@ -26111,6 +26128,201 @@ rs6000_global_entry_point_needed_p (void)
return cfun->machine->r2_setup_needed;
}
+/* Implement TARGET_SHRINK_WRAP_GET_SEPARATE_CONCERNS. */
+static sbitmap
+rs6000_get_separate_concerns (void)
+{
+ rs6000_stack_t *info = rs6000_stack_info ();
+
+ if (!(info->savres_strategy & SAVE_INLINE_GPRS)
+ || !(info->savres_strategy & REST_INLINE_GPRS)
+ || WORLD_SAVE_P (info))
+ return NULL;
+
+ sbitmap concerns = sbitmap_alloc (32);
+ bitmap_clear (concerns);
+
+ /* The GPRs we need saved to the frame. */
+ int reg_size = TARGET_32BIT ? 4 : 8;
+ int offset = info->gp_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+
+ for (unsigned regno = info->first_gp_reg_save; regno < 32; regno++)
+ {
+ if (IN_RANGE (offset, -0x8000, 0x7fff)
+ && rs6000_reg_live_or_pic_offset_p (regno))
+ bitmap_set_bit (concerns, regno);
+
+ offset += reg_size;
+ }
+
+ /* Don't mess with the hard frame pointer. */
+ if (frame_pointer_needed)
+ bitmap_clear_bit (concerns, HARD_FRAME_POINTER_REGNUM);
+
+ /* Don't mess with the fixed TOC register. */
+ if ((TARGET_TOC && TARGET_MINIMAL_TOC)
+ || (flag_pic == 1 && DEFAULT_ABI == ABI_V4)
+ || (flag_pic && DEFAULT_ABI == ABI_DARWIN))
+ bitmap_clear_bit (concerns, RS6000_PIC_OFFSET_TABLE_REGNUM);
+
+ /* Optimize LR save and restore if we can. This is concern 0. */
+ if (info->lr_save_p
+ && !(flag_pic && (DEFAULT_ABI == ABI_V4 || DEFAULT_ABI == ABI_DARWIN)))
+ {
+ offset = info->lr_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+ if (IN_RANGE (offset, -0x8000, 0x7fff))
+ bitmap_set_bit (concerns, 0);
+ }
+
+ return concerns;
+}
+
+/* Implement TARGET_SHRINK_WRAP_CONCERNS_FOR_BB. */
+static sbitmap
+rs6000_concerns_for_bb (basic_block bb)
+{
+ rs6000_stack_t *info = rs6000_stack_info ();
+
+ bitmap in = DF_LIVE_IN (bb);
+ bitmap gen = &DF_LIVE_BB_INFO (bb)->gen;
+ bitmap kill = &DF_LIVE_BB_INFO (bb)->kill;
+
+ sbitmap concerns = sbitmap_alloc (32);
+ bitmap_clear (concerns);
+
+ /* GPRs are used in a bb if they are in the IN, GEN, or KILL sets. */
+ for (unsigned regno = info->first_gp_reg_save; regno < 32; regno++)
+ if (bitmap_bit_p (in, regno)
+ || bitmap_bit_p (gen, regno)
+ || bitmap_bit_p (kill, regno))
+ bitmap_set_bit (concerns, regno);
+
+ /* LR needs to be saved around a bb if it is killed in that bb. */
+ if (bitmap_bit_p (kill, LR_REGNO))
+ bitmap_set_bit (concerns, 0);
+
+ return concerns;
+}
+
+/* Implement TARGET_SHRINK_WRAP_DISQUALIFY_CONCERNS. */
+static void
+rs6000_disqualify_concerns (sbitmap concerns, edge e, sbitmap edge_concerns,
+ bool /*is_prologue*/)
+{
+ /* Our LR pro/epilogue code moves LR via R0, so R0 had better not be
+ live where we want to place that code. */
+ if (bitmap_bit_p (edge_concerns, 0)
+ && bitmap_bit_p (DF_LIVE_IN (e->dest), 0))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Disqualifying LR because GPR0 is live "
+ "on entry to bb %d\n", e->dest->index);
+ bitmap_clear_bit (concerns, 0);
+ }
+}
+
+/* Implement TARGET_SHRINK_WRAP_EMIT_PROLOGUE_CONCERNS. */
+static void
+rs6000_emit_prologue_concerns (sbitmap concerns)
+{
+ rs6000_stack_t *info = rs6000_stack_info ();
+ rtx sp_reg_rtx = gen_rtx_REG (Pmode, STACK_POINTER_REGNUM);
+ int reg_size = TARGET_32BIT ? 4 : 8;
+
+ /* Prologue for LR. */
+ if (bitmap_bit_p (concerns, 0))
+ {
+ rtx reg = gen_rtx_REG (Pmode, 0);
+ emit_move_insn (reg, gen_rtx_REG (Pmode, LR_REGNO));
+ RTX_FRAME_RELATED_P (get_last_insn ()) = 1;
+
+ int offset = info->lr_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+
+ emit_insn (gen_frame_store (reg, sp_reg_rtx, offset));
+ RTX_FRAME_RELATED_P (get_last_insn ()) = 1;
+ }
+
+ /* Prologue for the GPRs. */
+ int offset = info->gp_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+
+ for (int i = info->first_gp_reg_save; i < 32; i++)
+ {
+ if (bitmap_bit_p (concerns, i))
+ {
+ rtx reg = gen_rtx_REG (Pmode, i);
+ emit_insn (gen_frame_store (reg, sp_reg_rtx, offset));
+ RTX_FRAME_RELATED_P (get_last_insn ()) = 1;
+ }
+
+ offset += reg_size;
+ }
+}
+
+/* Implement TARGET_SHRINK_WRAP_EMIT_EPILOGUE_CONCERNS. */
+static void
+rs6000_emit_epilogue_concerns (sbitmap concerns)
+{
+ rs6000_stack_t *info = rs6000_stack_info ();
+ rtx sp_reg_rtx = gen_rtx_REG (Pmode, STACK_POINTER_REGNUM);
+ int reg_size = TARGET_32BIT ? 4 : 8;
+
+ /* Epilogue for the GPRs. */
+ int offset = info->gp_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+
+ for (int i = info->first_gp_reg_save; i < 32; i++)
+ {
+ if (bitmap_bit_p (concerns, i))
+ {
+ rtx reg = gen_rtx_REG (Pmode, i);
+ emit_insn (gen_frame_load (reg, sp_reg_rtx, offset));
+ RTX_FRAME_RELATED_P (get_last_insn ()) = 1;
+ add_reg_note (get_last_insn (), REG_CFA_RESTORE, reg);
+ }
+
+ offset += reg_size;
+ }
+
+ /* Epilogue for LR. */
+ if (bitmap_bit_p (concerns, 0))
+ {
+ int offset = info->lr_save_offset;
+ if (info->push_p)
+ offset += info->total_size;
+
+ rtx reg = gen_rtx_REG (Pmode, 0);
+ emit_insn (gen_frame_load (reg, sp_reg_rtx, offset));
+
+ rtx lr = gen_rtx_REG (Pmode, LR_REGNO);
+ emit_move_insn (lr, reg);
+ RTX_FRAME_RELATED_P (get_last_insn ()) = 1;
+ add_reg_note (get_last_insn (), REG_CFA_RESTORE, lr);
+ }
+}
+
+/* Implement TARGET_SHRINK_WRAP_SET_HANDLED_CONCERNS. */
+static void
+rs6000_set_handled_concerns (sbitmap concerns)
+{
+ rs6000_stack_t *info = rs6000_stack_info ();
+
+ for (int i = info->first_gp_reg_save; i < 32; i++)
+ if (bitmap_bit_p (concerns, i))
+ cfun->machine->gpr_is_wrapped_separately[i] = true;
+
+ if (bitmap_bit_p (concerns, 0))
+ cfun->machine->lr_is_wrapped_separately = true;
+}
+
/* Emit function prologue as insns. */
void
@@ -26368,7 +26580,8 @@ rs6000_emit_prologue (void)
}
/* If we use the link register, get it into r0. */
- if (!WORLD_SAVE_P (info) && info->lr_save_p)
+ if (!WORLD_SAVE_P (info) && info->lr_save_p
+ && !cfun->machine->lr_is_wrapped_separately)
{
rtx addr, reg, mem;
@@ -26596,13 +26809,16 @@ rs6000_emit_prologue (void)
}
else if (!WORLD_SAVE_P (info))
{
- int i;
- for (i = 0; i < 32 - info->first_gp_reg_save; i++)
- if (rs6000_reg_live_or_pic_offset_p (info->first_gp_reg_save + i))
- emit_frame_save (frame_reg_rtx, reg_mode,
- info->first_gp_reg_save + i,
- info->gp_save_offset + frame_off + reg_size * i,
- sp_off - frame_off);
+ int offset = info->gp_save_offset + frame_off;
+ for (int i = info->first_gp_reg_save; i < 32; i++)
+ {
+ if (rs6000_reg_live_or_pic_offset_p (i)
+ && !cfun->machine->gpr_is_wrapped_separately[i])
+ emit_frame_save (frame_reg_rtx, reg_mode, i, offset,
+ sp_off - frame_off);
+
+ offset += reg_size;
+ }
}
if (crtl->calls_eh_return)
@@ -27407,6 +27623,9 @@ load_lr_save (int regno, rtx frame_reg_rtx, int offset)
static void
restore_saved_lr (int regno, bool exit_func)
{
+ if (cfun->machine->lr_is_wrapped_separately)
+ return;
+
rtx reg = gen_rtx_REG (Pmode, regno);
rtx lr = gen_rtx_REG (Pmode, LR_REGNO);
rtx_insn *insn = emit_move_insn (lr, reg);
@@ -28164,12 +28383,18 @@ rs6000_emit_epilogue (int sibcall)
}
else
{
- for (i = 0; i < 32 - info->first_gp_reg_save; i++)
- if (rs6000_reg_live_or_pic_offset_p (info->first_gp_reg_save + i))
- emit_insn (gen_frame_load
- (gen_rtx_REG (reg_mode, info->first_gp_reg_save + i),
- frame_reg_rtx,
- info->gp_save_offset + frame_off + reg_size * i));
+ int offset = info->gp_save_offset + frame_off;
+ for (i = info->first_gp_reg_save; i < 32; i++)
+ {
+ if (rs6000_reg_live_or_pic_offset_p (i)
+ && !cfun->machine->gpr_is_wrapped_separately[i])
+ {
+ rtx reg = gen_rtx_REG (reg_mode, i);
+ emit_insn (gen_frame_load (reg, frame_reg_rtx, offset));
+ }
+
+ offset += reg_size;
+ }
}
if (DEFAULT_ABI == ABI_V4 || flag_shrink_wrap)
@@ -28208,8 +28433,10 @@ rs6000_emit_epilogue (int sibcall)
|| using_load_multiple
|| rs6000_reg_live_or_pic_offset_p (i))
{
- rtx reg = gen_rtx_REG (reg_mode, i);
+ if (cfun->machine->gpr_is_wrapped_separately[i])
+ continue;
+ rtx reg = gen_rtx_REG (reg_mode, i);
cfa_restores = alloc_reg_note (REG_CFA_RESTORE, reg, cfa_restores);
}
}
--
1.9.3
