Such operation can be done either bitwise-XOR or addition with -2147483648,
but the latter is one byte less if TARGET_DENSITY.
gcc/ChangeLog:
* config/xtensa/xtensa.md (xorsi3_internal):
Rename from the original of "xorsi3".
(xorsi3): New expansion pattern that emits addition rather than
bitwise-XOR when the second source is a constant of -2147483648
if TARGET_DENSITY.
---
gcc/config/xtensa/xtensa.md | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 0a477e711..4b5899a4c 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -736,7 +736,31 @@
(set_attr "mode" "SI")
(set_attr "length" "3")])
-(define_insn "xorsi3"
+(define_expand "xorsi3"
+ [(set (match_operand:SI 0 "register_operand")
+ (xor:SI (match_operand:SI 1 "register_operand")
+ (match_operand:SI 2 "nonmemory_operand")))]
+ ""
+{
+ if (register_operand (operands[2], SImode))
+ emit_insn (gen_xorsi3_internal (operands[0], operands[1],
+ operands[2]));
+ else
+ {
+ rtx (*gen_op)(rtx, rtx, rtx);
+ if (TARGET_DENSITY
+ && CONST_INT_P (operands[2])
+ && INTVAL (operands[2]) == -2147483648L)
+ gen_op = gen_addsi3;
+ else
+ gen_op = gen_xorsi3_internal;
+ emit_insn (gen_op (operands[0], operands[1],
+ force_reg (SImode, operands[2])));
+ }
+ DONE;
+})
+
+(define_insn "xorsi3_internal"
[(set (match_operand:SI 0 "register_operand" "=a")
(xor:SI (match_operand:SI 1 "register_operand" "%r")
(match_operand:SI 2 "register_operand" "r")))]
--
2.30.2
