Hello list,
The attached patch does two things for df_get_call_refs():
* First it uses HARD_REG_SETs for defs_generated and
regs_invalidated_by_call, instead of bitmaps. Replacing in total more
than 400K calls (for my testcase) to bitmap_bit_p() with the much faster
TEST_HARD_REG_BIT, reduces the total instruction count from about 13M to
1.5M.
* Second it produces the REFs in REGNO order, which is important to keep
the collection_rec sorted most times, and avoid expensive calls to
qsort(). Thanks to Paolo Bonzini for idea and mentoring.
The second part makes a big difference if accompanied with another patch
in df_insn_refs_collect(). I'll post a followup patch, that is
unfortunately unstable for some of my tests, so I'd appreciate any
comments.
Thanks,
Dimitris
=== modified file 'gcc/df-scan.c'
--- gcc/df-scan.c 2011-02-02 20:08:06 +0000
+++ gcc/df-scan.c 2011-07-08 01:28:55 +0000
@@ -3317,20 +3317,56 @@
int flags)
{
rtx note;
- bitmap_iterator bi;
- unsigned int ui;
bool is_sibling_call;
unsigned int i;
df_ref def;
- bitmap_head defs_generated;
+ HARD_REG_SET defs_generated;
- bitmap_initialize (&defs_generated, &df_bitmap_obstack);
+ CLEAR_HARD_REG_SET(defs_generated);
/* Do not generate clobbers for registers that are the result of the
call. This causes ordering problems in the chain building code
depending on which def is seen first. */
FOR_EACH_VEC_ELT (df_ref, collection_rec->def_vec, i, def)
- bitmap_set_bit (&defs_generated, DF_REF_REGNO (def));
+ SET_HARD_REG_BIT (defs_generated, DF_REF_REGNO (def));
+
+ is_sibling_call = SIBLING_CALL_P (insn_info->insn);
+
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ {
+ if (i == STACK_POINTER_REGNUM)
+ /* The stack ptr is used (honorarily) by a CALL insn. */
+ df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
+ NULL, bb, insn_info, DF_REF_REG_USE,
+ DF_REF_CALL_STACK_USAGE | flags);
+ else if (global_regs[i])
+ {
+ /* Calls to const functions cannot access any global registers and
+ calls to pure functions cannot set them. All other calls may
+ reference any of the global registers, so they are recorded as
+ used. */
+ if (!RTL_CONST_CALL_P (insn_info->insn))
+ {
+ df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
+ NULL, bb, insn_info, DF_REF_REG_USE, flags);
+ if (!RTL_PURE_CALL_P (insn_info->insn))
+ df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
+ NULL, bb, insn_info, DF_REF_REG_DEF, flags);
+ }
+ }
+ /* TODO HARD_REG_SET set intersection! */
+ else /* !global_regs[i] */
+ /* track Caller-Saved registers */
+ if (TEST_HARD_REG_BIT(regs_invalidated_by_call, i)
+ && !TEST_HARD_REG_BIT (defs_generated, i)
+ && (!is_sibling_call
+ || !bitmap_bit_p (df->exit_block_uses, i)
+ || refers_to_regno_p (i, i+1,
+ crtl->return_rtx, NULL)))
+ df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
+ NULL, bb, insn_info, DF_REF_REG_DEF,
+ DF_REF_MAY_CLOBBER | flags);
+ }
/* Record the registers used to pass arguments, and explicitly
noted as clobbered. */
@@ -3345,7 +3381,7 @@
if (REG_P (XEXP (XEXP (note, 0), 0)))
{
unsigned int regno = REGNO (XEXP (XEXP (note, 0), 0));
- if (!bitmap_bit_p (&defs_generated, regno))
+ if (!TEST_HARD_REG_BIT (defs_generated, regno))
df_defs_record (collection_rec, XEXP (note, 0), bb,
insn_info, flags);
}
@@ -3355,40 +3391,6 @@
}
}
- /* The stack ptr is used (honorarily) by a CALL insn. */
- df_ref_record (DF_REF_BASE, collection_rec,
regno_reg_rtx[STACK_POINTER_REGNUM],
- NULL, bb, insn_info, DF_REF_REG_USE,
- DF_REF_CALL_STACK_USAGE | flags);
-
- /* Calls to const functions cannot access any global registers and calls to
- pure functions cannot set them. All other calls may reference any of the
- global registers, so they are recorded as used. */
- if (!RTL_CONST_CALL_P (insn_info->insn))
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (global_regs[i])
- {
- df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
- NULL, bb, insn_info, DF_REF_REG_USE, flags);
- if (!RTL_PURE_CALL_P (insn_info->insn))
- df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
- NULL, bb, insn_info, DF_REF_REG_DEF, flags);
- }
-
- is_sibling_call = SIBLING_CALL_P (insn_info->insn);
- EXECUTE_IF_SET_IN_BITMAP (regs_invalidated_by_call_regset, 0, ui, bi)
- {
- if (!global_regs[ui]
- && (!bitmap_bit_p (&defs_generated, ui))
- && (!is_sibling_call
- || !bitmap_bit_p (df->exit_block_uses, ui)
- || refers_to_regno_p (ui, ui+1,
- crtl->return_rtx, NULL)))
- df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[ui],
- NULL, bb, insn_info, DF_REF_REG_DEF,
- DF_REF_MAY_CLOBBER | flags);
- }
-
- bitmap_clear (&defs_generated);
return;
}
