rtl-optimization/110587 - remove quadratic regno_in_use_p
Checks
Commit Message
The following removes the code checking whether a noop copy
is between something involved in the return sequence composed
of a SET and USE. Instead of checking for this special-case
the following makes us only ever remove noop copies between
pseudos - which is the case that is necessary for IRA/LRA
interfacing to function according to the comment. That makes
looking for the return reg special case unnecessary, reducing
the compile-time in LRA non-specific to zero for the testcase.
Bootstrapped and tested on x86_64-unknown-linux-gnu with
all languages and {,-m32}.
OK?
Thanks,
Richard.
PR rtl-optimization/110587
* lra-spills.cc (return_regno_p): Remove.
(regno_in_use_p): Likewise.
(lra_final_code_change): Do not remove noop moves
between hard registers.
---
gcc/lra-spills.cc | 69 +----------------------------------------------
1 file changed, 1 insertion(+), 68 deletions(-)
@@ -705,72 +705,6 @@ alter_subregs (rtx *loc, bool final_p)
return res;
}
-/* Return true if REGNO is used for return in the current
- function. */
-static bool
-return_regno_p (unsigned int regno)
-{
- rtx outgoing = crtl->return_rtx;
-
- if (! outgoing)
- return false;
-
- if (REG_P (outgoing))
- return REGNO (outgoing) == regno;
- else if (GET_CODE (outgoing) == PARALLEL)
- {
- int i;
-
- for (i = 0; i < XVECLEN (outgoing, 0); i++)
- {
- rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
-
- if (REG_P (x) && REGNO (x) == regno)
- return true;
- }
- }
- return false;
-}
-
-/* Return true if REGNO is in one of subsequent USE after INSN in the
- same BB. */
-static bool
-regno_in_use_p (rtx_insn *insn, unsigned int regno)
-{
- static lra_insn_recog_data_t id;
- static struct lra_static_insn_data *static_id;
- struct lra_insn_reg *reg;
- int i, arg_regno;
- basic_block bb = BLOCK_FOR_INSN (insn);
-
- while ((insn = next_nondebug_insn (insn)) != NULL_RTX)
- {
- if (BARRIER_P (insn) || bb != BLOCK_FOR_INSN (insn))
- return false;
- if (! INSN_P (insn))
- continue;
- if (GET_CODE (PATTERN (insn)) == USE
- && REG_P (XEXP (PATTERN (insn), 0))
- && regno == REGNO (XEXP (PATTERN (insn), 0)))
- return true;
- /* Check that the regno is not modified. */
- id = lra_get_insn_recog_data (insn);
- for (reg = id->regs; reg != NULL; reg = reg->next)
- if (reg->type != OP_IN && reg->regno == (int) regno)
- return false;
- static_id = id->insn_static_data;
- for (reg = static_id->hard_regs; reg != NULL; reg = reg->next)
- if (reg->type != OP_IN && reg->regno == (int) regno)
- return false;
- if (id->arg_hard_regs != NULL)
- for (i = 0; (arg_regno = id->arg_hard_regs[i]) >= 0; i++)
- if ((int) regno == (arg_regno >= FIRST_PSEUDO_REGISTER
- ? arg_regno : arg_regno - FIRST_PSEUDO_REGISTER))
- return false;
- }
- return false;
-}
-
/* Final change of pseudos got hard registers into the corresponding
hard registers and removing temporary clobbers. */
void
@@ -821,8 +755,7 @@ lra_final_code_change (void)
if (NONJUMP_INSN_P (insn) && GET_CODE (pat) == SET
&& REG_P (SET_SRC (pat)) && REG_P (SET_DEST (pat))
&& REGNO (SET_SRC (pat)) == REGNO (SET_DEST (pat))
- && (! return_regno_p (REGNO (SET_SRC (pat)))
- || ! regno_in_use_p (insn, REGNO (SET_SRC (pat)))))
+ && REGNO (SET_SRC (pat)) >= FIRST_PSEUDO_REGISTER)
{
lra_invalidate_insn_data (insn);
delete_insn (insn);