* config/cris/cris.md ("movsi"): For a zero-source post-reload,
generate a clobberless variant.
("*mov_fromzero<mode>_split"): New split.
("*mov_fromzero<mode>"): New insn.
A separated follow-up to the previous change: Also emit moves
from zero as not clobbering condition-codes.
---
gcc/config/cris/cris.md | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/gcc/config/cris/cris.md b/gcc/config/cris/cris.md
index 3de2f5a13..bf2cf9663 100644
--- a/gcc/config/cris/cris.md
+++ b/gcc/config/cris/cris.md
@@ -449,8 +449,9 @@ (define_expand "movsi"
/* At post-reload time, we'll get here for e.g. split multi-mode insns
with a memory destination. Go directly to the clobber-less variant.
- FIXME: Also applies to zero source. */
- if (MEM_P (operands[0]) && reload_completed)
+ FIXME: Also applies to special-register source or destination. */
+ if (reload_completed
+ && (MEM_P (operands[0]) || operands[1] == const0_rtx))
{
emit_insn (gen_rtx_SET (operands[0], operands[1]));
DONE;
@@ -697,6 +698,20 @@ (define_insn "*mov_tomem<mode>"
move %1,%0"
[(set_attr "slottable" "yes,yes,yes,no,no,no")
(set_attr "enabled" "<mov_tomem_enabled>")])
+
+(define_split ;; "*mov_fromzero<mode>_split"
+ [(set (match_operand:BWD 0 "register_operand") (const_int 0))
+ (clobber (reg:CC CRIS_CC0_REGNUM))]
+ "reload_completed
+ && REGNO(operands[0]) <= CRIS_LAST_GENERAL_REGISTER"
+ [(set (match_dup 0) (const_int 0))]
+ "")
+
+(define_insn "*mov_fromzero<mode>"
+ [(set (match_operand:BWD 0 "register_operand" "=r") (const_int 0))]
+ "reload_completed"
+ "clear<m> %0"
+ [(set_attr "slottable" "yes")])
;; Movem patterns. Primarily for use in function prologue and epilogue.
;; Unfortunately, movem stores R0 in the highest memory location, thus
--
2.11.0
brgds, H-P
