Fix clearing ZERO_REG

Fix clearing ZERO_REG
	* config/avr/avr.md (cc): Add alternative "ldi".
	(movqi_insn): Use it in cc attribute.
	* config/avr/avr.c (notice_update_cc): Handle CC_LDI.
	(output_reload_in_const): Use CLR to move 0 to ZERO_REG.
	(output_reload_insisf): Use ZERO_REG to pre-clear register.

From-SVN: r182871
This commit is contained in:
Georg-Johann Lay 2012-01-04 12:39:26 +00:00 committed by Georg-Johann Lay
parent 74d1a34e86
commit 299c4b5f88
3 changed files with 48 additions and 16 deletions

View File

@ -1,3 +1,12 @@
2012-01-04 Georg-Johann Lay <avr@gjlay.de>
Fix clearing ZERO_REG
* config/avr/avr.md (cc): Add alternative "ldi".
(movqi_insn): Use it in cc attribute.
* config/avr/avr.c (notice_update_cc): Handle CC_LDI.
(output_reload_in_const): Use CLR to move 0 to ZERO_REG.
(output_reload_insisf): Use ZERO_REG to pre-clear register.
2012-01-04 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* configure: Regenerate.

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@ -1994,6 +1994,7 @@ notice_update_cc (rtx body ATTRIBUTE_UNUSED, rtx insn)
case CC_OUT_PLUS:
case CC_OUT_PLUS_NOCLOBBER:
case CC_LDI:
{
rtx *op = recog_data.operand;
int len_dummy, icc;
@ -2001,16 +2002,36 @@ notice_update_cc (rtx body ATTRIBUTE_UNUSED, rtx insn)
/* Extract insn's operands. */
extract_constrain_insn_cached (insn);
if (CC_OUT_PLUS == cc)
avr_out_plus (op, &len_dummy, &icc);
else
avr_out_plus_noclobber (op, &len_dummy, &icc);
cc = (enum attr_cc) icc;
switch (cc)
{
default:
gcc_unreachable();
case CC_OUT_PLUS:
avr_out_plus (op, &len_dummy, &icc);
cc = (enum attr_cc) icc;
break;
case CC_OUT_PLUS_NOCLOBBER:
avr_out_plus_noclobber (op, &len_dummy, &icc);
cc = (enum attr_cc) icc;
break;
case CC_LDI:
cc = (op[1] == CONST0_RTX (GET_MODE (op[0]))
&& reg_overlap_mentioned_p (op[0], zero_reg_rtx))
/* Loading zero-reg with 0 uses CLI and thus clobbers cc0. */
? CC_CLOBBER
/* Any other "r,rL" combination does not alter cc0. */
: CC_NONE;
break;
} /* inner switch */
break;
}
}
} /* outer swicth */
switch (cc)
{
@ -8945,9 +8966,9 @@ avr_regno_mode_code_ok_for_base_p (int regno,
The effect on cc0 is as follows:
Load 0 to any register : NONE
Load ld register with any value : NONE
Anything else: : CLOBBER */
Load 0 to any register except ZERO_REG : NONE
Load ld register with any value : NONE
Anything else: : CLOBBER */
static void
output_reload_in_const (rtx *op, rtx clobber_reg, int *len, bool clear_p)
@ -9062,7 +9083,9 @@ output_reload_in_const (rtx *op, rtx clobber_reg, int *len, bool clear_p)
if (ival[n] == 0)
{
if (!clear_p)
avr_asm_len (ldreg_p ? "ldi %0,0" : "mov %0,__zero_reg__",
avr_asm_len (ldreg_p ? "ldi %0,0"
: ZERO_REGNO == REGNO (xdest[n]) ? "clr %0"
: "mov %0,__zero_reg__",
&xdest[n], len, 1);
continue;
}
@ -9224,8 +9247,8 @@ output_reload_insisf (rtx *op, rtx clobber_reg, int *len)
{
/* Default needs 4 CLR instructions: clear register beforehand. */
avr_asm_len ("clr %A0" CR_TAB
"clr %B0" CR_TAB
avr_asm_len ("mov %A0,__zero_reg__" CR_TAB
"mov %B0,__zero_reg__" CR_TAB
"movw %C0,%A0", &op[0], len, 3);
output_reload_in_const (op, clobber_reg, len, true);

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@ -95,7 +95,7 @@
;; Condition code settings.
(define_attr "cc" "none,set_czn,set_zn,set_n,compare,clobber,
out_plus, out_plus_noclobber"
out_plus, out_plus_noclobber,ldi"
(const_string "none"))
(define_attr "type" "branch,branch1,arith,xcall"
@ -584,7 +584,7 @@
}
[(set_attr "length" "1,1,5,5,1,1,4")
(set_attr "adjust_len" "mov8")
(set_attr "cc" "none,none,clobber,clobber,none,none,clobber")])
(set_attr "cc" "ldi,none,clobber,clobber,none,none,clobber")])
;; This is used in peephole2 to optimize loading immediate constants
;; if a scratch register from LD_REGS happens to be available.