ix86_access_stack_p can be quite expensive. Don't check symbolic constant
load. Instead, call ix86_access_stack_p only if an INSN needs alignment
> stack alignment. This reduces the compile time of PR target/124684 from
185 seconds to 24 seconds. The compile time of PR target/124165 test is
unchanged.
PR target/124165
PR target/124684
* config/i386/i386.cc (ix86_symbolic_const_load_p_1): Renamed to
...
(ix86_need_alignment_p_1): This.
(ix86_symbolic_const_load_p): Renamed to ...
(ix86_need_alignment_p): This.
(ix86_find_max_used_stack_alignment): Call ix86_access_stack_p
only if the INSN needs alignment > stack alignment.
Signed-off-by: H.J. Lu <[email protected]>
---
gcc/config/i386/i386.cc | 63 ++++++++++-------------------------------
1 file changed, 15 insertions(+), 48 deletions(-)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 3f7fe0bcf0c..588e7c9d81d 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -8781,19 +8781,15 @@ ix86_access_stack_p (unsigned int regno, basic_block bb,
return false;
}
-/* Helper function for ix86_symbolic_const_load_p. */
+/* Return true if SET needs alignment > ALIGNMENT. */
static bool
-ix86_symbolic_const_load_p_1 (rtx set)
+ix86_need_alignment_p_1 (rtx set, unsigned int alignment)
{
rtx dest = SET_DEST (set);
- if (!REG_P (dest))
- return false;
-
- /* Reject non-Pmode modes. */
- if (GET_MODE (dest) != Pmode)
- return false;
+ if (MEM_P (dest))
+ return GET_MODE_ALIGNMENT (GET_MODE (dest)) > alignment;
const_rtx src = SET_SRC (set);
@@ -8803,22 +8799,20 @@ ix86_symbolic_const_load_p_1 (rtx set)
auto op = *iter;
if (MEM_P (op))
- iter.skip_subrtxes ();
- else if (SYMBOLIC_CONST (op))
- return true;
+ return GET_MODE_ALIGNMENT (GET_MODE (op)) > alignment;
}
return false;
}
-/* Return true if INSN loads a symbolic constant into register REGNO. */
+/* Return true if INSN needs alignment > ALIGNMENT. */
static bool
-ix86_symbolic_const_load_p (rtx_insn *insn, unsigned int regno)
+ix86_need_alignment_p (rtx_insn *insn, unsigned int alignment)
{
rtx set = single_set (insn);
if (set)
- return ix86_symbolic_const_load_p_1 (set);
+ return ix86_need_alignment_p_1 (set, alignment);
rtx pat = PATTERN (insn);
if (GET_CODE (pat) != PARALLEL)
@@ -8828,15 +8822,9 @@ ix86_symbolic_const_load_p (rtx_insn *insn, unsigned int
regno)
{
rtx exp = XVECEXP (pat, 0, i);
- if (GET_CODE (exp) == SET)
- {
- rtx dest = SET_DEST (exp);
- if (REG_P (dest)
- && GET_MODE (dest) == Pmode
- && REGNO (dest) == regno
- && ix86_symbolic_const_load_p_1 (exp))
- return true;
- }
+ if (GET_CODE (exp) == SET
+ && ix86_need_alignment_p_1 (exp, alignment))
+ return true;
}
return false;
@@ -8902,8 +8890,6 @@ ix86_find_max_used_stack_alignment (unsigned int
&stack_alignment,
bitmap_set_bit (worklist, HARD_FRAME_POINTER_REGNUM);
}
- HARD_REG_SET hard_stack_slot_access = stack_slot_access;
-
calculate_dominance_info (CDI_DOMINATORS);
unsigned int regno;
@@ -8925,25 +8911,6 @@ ix86_find_max_used_stack_alignment (unsigned int
&stack_alignment,
EXECUTE_IF_SET_IN_HARD_REG_SET (stack_slot_access, 0, regno, hrsi)
{
- /* Set to true if there is a symbolic constant load into REGNO. */
- bool symbolic_const_load_p = false;
-
- if (!TEST_HARD_REG_BIT (hard_stack_slot_access, regno))
- for (df_ref def = DF_REG_DEF_CHAIN (regno);
- def;
- def = DF_REF_NEXT_REG (def))
- if (!DF_REF_IS_ARTIFICIAL (def)
- && !DF_REF_FLAGS_IS_SET (def, DF_REF_MAY_CLOBBER)
- && !DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER))
- {
- rtx_insn *insn = DF_REF_INSN (def);
- if (ix86_symbolic_const_load_p (insn, regno))
- {
- symbolic_const_load_p = true;
- break;
- }
- }
-
for (df_ref ref = DF_REG_USE_CHAIN (regno);
ref != NULL;
ref = DF_REF_NEXT_REG (ref))
@@ -8956,10 +8923,10 @@ ix86_find_max_used_stack_alignment (unsigned int
&stack_alignment,
if (!NONJUMP_INSN_P (insn))
continue;
- /* If there is no symbolic constant load into the register,
- don't call ix86_access_stack_p. */
- if (!symbolic_const_load_p
- || ix86_access_stack_p (regno, BLOCK_FOR_INSN (insn),
+ /* Call ix86_access_stack_p only if INSN needs alignment >
+ STACK_ALIGNMENT. */
+ if (ix86_need_alignment_p (insn, stack_alignment)
+ && ix86_access_stack_p (regno, BLOCK_FOR_INSN (insn),
set_up_by_prologue, prologue_used,
reg_dominate_bbs_known,
reg_dominate_bbs))
--
2.53.0
