This patch optimizes the boolean evaluation for equality to 0 in SImode
using the MINU (Minimum Value Unsigned) machine instruction available
when TARGET_MINMAX is configured, for example, (x != 0) to MINU(x, 1)
and (x == 0) to (MINU(x, 1) ^ 1).
/* example */
int test0(int x) {
return x == 0;
}
int test1(int x) {
return x != 0;
}
;; before
test0:
mov.n a10, a2
movi.n a9, 1
movi.n a2, 0
moveqz a2, a9, a10
ret.n
test1:
mov.n a10, a2
movi.n a9, 1
movi.n a2, 0
movnez a2, a9, a10
ret.n
;; after (prereq. TARGET_MINMAX)
test0:
movi.n a9, 1
minu a2, a2, a9
xor a2, a2, a9
ret.n
test1:
movi.n a9, 1
minu a2, a2, a9
ret.n
gcc/ChangeLog:
* config/xtensa/xtensa.cc (xtensa_expand_scc):
Add code for particular constants (only 0 and INT_MIN for now)
for EQ/NE boolean evaluation in SImode.
* config/xtensa/xtensa.md (*eqne_INT_MIN): Remove because its
implementation has been integrated into the above.
---
gcc/config/xtensa/xtensa.cc | 43 +++++++++++++++++++++++++++++++------
gcc/config/xtensa/xtensa.md | 34 -----------------------------
2 files changed, 37 insertions(+), 40 deletions(-)
diff --git a/gcc/config/xtensa/xtensa.cc b/gcc/config/xtensa/xtensa.cc
index af71e2179d0..1afaa1cc94e 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -994,15 +994,46 @@ xtensa_expand_scc (rtx operands[4], machine_mode cmp_mode)
rtx cmp;
rtx one_tmp, zero_tmp;
rtx (*gen_fn) (rtx, rtx, rtx, rtx, rtx);
+ enum rtx_code code = GET_CODE (operands[1]);
- if (!(cmp = gen_conditional_move (GET_CODE (operands[1]), cmp_mode,
- operands[2], operands[3])))
+ if (cmp_mode == SImode && CONST_INT_P (operands[3])
+ && (code == EQ || code == NE))
+ switch (INTVAL (operands[3]))
+ {
+ case 0:
+ if (TARGET_MINMAX)
+ {
+ one_tmp = force_reg (SImode, const1_rtx);
+ emit_insn (gen_uminsi3 (dest, operands[2], one_tmp));
+ if (code == EQ)
+ emit_insn (gen_xorsi3 (dest, dest, one_tmp));
+ return 1;
+ }
+ break;
+ case -2147483648:
+ if (TARGET_ABS)
+ {
+ emit_insn (gen_abssi2 (dest, operands[2]));
+ if (code == EQ)
+ emit_insn (gen_lshrsi3 (dest, dest, GEN_INT (31)));
+ else
+ {
+ emit_insn (gen_ashrsi3 (dest, dest, GEN_INT (31)));
+ emit_insn (gen_addsi3 (dest, dest, const1_rtx));
+ }
+ return 1;
+ }
+ break;
+ default:
+ break;
+ }
+
+ if (! (cmp = gen_conditional_move (code, cmp_mode,
+ operands[2], operands[3])))
return 0;
- one_tmp = gen_reg_rtx (SImode);
- zero_tmp = gen_reg_rtx (SImode);
- emit_insn (gen_movsi (one_tmp, const_true_rtx));
- emit_insn (gen_movsi (zero_tmp, const0_rtx));
+ one_tmp = force_reg (SImode, const1_rtx);
+ zero_tmp = force_reg (SImode, const0_rtx);
gen_fn = (cmp_mode == SImode
? gen_movsicc_internal0
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 5386e45b51d..d6505e7eb70 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -3188,40 +3188,6 @@
(const_int 5)
(const_int 6)))])
-
-(define_insn_and_split "*eqne_INT_MIN"
- [(set (match_operand:SI 0 "register_operand" "=a")
- (match_operator:SI 2 "boolean_operator"
- [(match_operand:SI 1 "register_operand" "r")
- (const_int -2147483648)]))]
- "TARGET_ABS"
- "#"
- "&& 1"
- [(set (match_dup 0)
- (abs:SI (match_dup 1)))
- (set (match_dup 0)
- (match_op_dup:SI 2
- [(match_dup 0)
- (const_int 31)]))
- (match_dup 3)]
-{
- enum rtx_code code = GET_CODE (operands[2]);
- operands[2] = gen_rtx_fmt_ee ((code == EQ) ? LSHIFTRT : ASHIFTRT,
- SImode, XEXP (operands[2], 0),
- XEXP (operands[2], 1));
- operands[3] = (code != EQ) ? gen_addsi3 (operands[0],
- operands[0], const1_rtx)
- : const0_rtx;
-}
- [(set_attr "type" "move")
- (set_attr "mode" "SI")
- (set (attr "length")
- (if_then_else (match_test "GET_CODE (operands[2]) == EQ")
- (const_int 3)
- (if_then_else (match_test "TARGET_DENSITY")
- (const_int 5)
- (const_int 6))))])
-
(define_peephole2
[(set (match_operand:SI 0 "register_operand")
(match_operand:SI 6 "reload_operand"))
--
2.30.2
