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re PR target/51244 ([SH] Inefficient conditional branch and code around T bit)

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gcc/
	PR target/51244
	* config/sh/sh_treg_combine.cc (sh_treg_combine::try_optimize_cbranch):
	Combine ccreg inversion and cbranch into inverted cbranch.

From-SVN: r218847
This commit is contained in:
Oleg Endo 2014-12-17 22:52:21 +00:00
parent 64e6d5c442
commit ff49a9ba7b
2 changed files with 28 additions and 1 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2014-12-17 Oleg Endo <olegendo@gcc.gnu.org>
PR target/51244
* config/sh/sh_treg_combine.cc (sh_treg_combine::try_optimize_cbranch):
Combine ccreg inversion and cbranch into inverted cbranch.
2014-12-17 Vladimir Makarov <vmakarov@redhat.com>
* lra-constraints.c (process_alt_operands): Remove non

23
gcc/config/sh/sh_treg_combine.cc
View File

@ -1339,9 +1339,17 @@ sh_treg_combine::try_optimize_cbranch (rtx_insn *insn)
// for now we limit the search to the current basic block.
trace.setcc = find_set_of_reg_bb (m_ccreg, prev_nonnote_insn_bb (insn));
if (!is_cmp_eq_zero (trace.setcc.set_src ()))
if (trace.setcc.set_src () == NULL_RTX)
log_return_void ("could not find set of ccreg in current BB\n");
if (!is_cmp_eq_zero (trace.setcc.set_src ())
&& !is_inverted_ccreg (trace.setcc.set_src ()))
{
log_msg ("unsupported set of ccreg in current BB: ");
log_rtx (trace.setcc.set_src ());
log_return_void ("\n");
}
rtx trace_reg = XEXP (trace.setcc.set_src (), 0);
log_msg ("set of ccreg:\n");
@ -1358,6 +1366,19 @@ sh_treg_combine::try_optimize_cbranch (rtx_insn *insn)
log_return_void ("\nbecause it's volatile\n");
}
// If the ccreg is inverted before cbranch try inverting the branch
// condition.
if (is_inverted_ccreg (trace.setcc.set_src ()))
{
if (!trace.can_invert_condition ())
log_return_void ("branch condition can't be inverted - aborting\n");
if (try_invert_branch_condition (trace))
delete_insn (trace.setcc.insn);
return;
}
// Now that we have an insn which tests some reg and sets the condition
// reg before the conditional branch, try to figure out how that tested
// reg was formed, i.e. find all the insns that set the tested reg in