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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.c (sh_eval_treg_value): Handle t_reg_operand and
	negt_reg_operand cases.
	* config/sh/sh.md (*cset_zero): Likewise by using cbranch_treg_value
	predicate.
	* config/sh/predicates.md (cbranch_treg_value): Simplify.

From-SVN: r210535
This commit is contained in:
Oleg Endo 2014-05-16 22:54:32 +00:00
parent d580af0f7a
commit 48d8568e1f
4 changed files with 29 additions and 9 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2014-05-16 Oleg Endo <olegendo@gcc.gnu.org>
PR target/51244
* config/sh/sh.c (sh_eval_treg_value): Handle t_reg_operand and
negt_reg_operand cases.
* config/sh/sh.md (*cset_zero): Likewise by using cbranch_treg_value
predicate.
* config/sh/predicates.md (cbranch_treg_value): Simplify.
2014-05-16 Oleg Endo <olegendo@gcc.gnu.org>
* config/sh/sh.c (sh_option_override): Set branch cost to 2 for all

6
gcc/config/sh/predicates.md
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@ -1119,10 +1119,8 @@
;; A predicate that returns true if OP is a valid construct around the T bit
;; that can be used as an operand for conditional branches.
(define_predicate "cbranch_treg_value"
(match_code "eq,ne,reg,subreg,xor,sign_extend,zero_extend")
{
return sh_eval_treg_value (op) >= 0;
})
(and (match_code "eq,ne,reg,subreg,xor,sign_extend,zero_extend")
(match_test "sh_eval_treg_value (op) >= 0")))
;; Returns true if OP is arith_reg_operand or t_reg_operand.
(define_predicate "arith_reg_or_t_reg_operand"

7
gcc/config/sh/sh.c
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@ -2250,7 +2250,12 @@ expand_cbranchdi4 (rtx *operands, enum rtx_code comparison)
int
sh_eval_treg_value (rtx op)
{
enum rtx_code code = GET_CODE (op);
if (t_reg_operand (op, GET_MODE (op)))
return 1;
if (negt_reg_operand (op, GET_MODE (op)))
return 0;
rtx_code code = GET_CODE (op);
if ((code != EQ && code != NE) || !CONST_INT_P (XEXP (op, 1)))
return -1;

16
gcc/config/sh/sh.md
View File

@ -11624,14 +11624,22 @@ label:
(define_insn "*cset_zero"
[(set (match_operand:SI 0 "arith_reg_dest" "=r")
(if_then_else:SI (match_operand:SI 1 "t_reg_operand")
(if_then_else:SI (match_operand:SI 1 "cbranch_treg_value")
(match_operand:SI 2 "arith_reg_operand" "0")
(const_int 0)))]
"TARGET_SH1 && TARGET_ZDCBRANCH"
{
return "bt 0f" "\n"
" mov #0,%0" "\n"
"0:";
int tval = sh_eval_treg_value (operands[1]);
if (tval == true)
return "bt 0f" "\n"
" mov #0,%0" "\n"
"0:";
else if (tval == false)
return "bf 0f" "\n"
" mov #0,%0" "\n"
"0:";
else
gcc_unreachable ();
}
[(set_attr "type" "arith") ;; poor approximation
(set_attr "length" "4")])