In Xtensa ISA, there is no single machine instruction that calculates unary
bitwise negation, but a few similar fused instructions are exist:
"BALL Ax, Ay, label" // if ((~Ax & Ay) == 0) goto label;
"BNALL Ax, Ay, label" // if ((~Ax & Ay) != 0) goto label;
These instructions have never been emitted before, but it seems no
reason not
to make use of them.
gcc/ChangeLog:
* config/xtensa/xtensa.md (*masktrue_bitcmpl): New insn pattern.
gcc/testsuite/ChangeLog:
* gcc.target/xtensa/BALL-BNALL.c: New.
---
gcc/config/xtensa/xtensa.md | 21 +
gcc/testsuite/gcc.target/xtensa/BALL-BNALL.c | 33
2 files changed, 54 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/xtensa/BALL-BNALL.c
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index 25b8d2fb3c9..090a2939684 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -1627,6 +1627,27 @@
(set_attr "mode" "none")
(set_attr "length""3")])
+(define_insn "*masktrue_bitcmpl"
+ [(set (pc)
+ (if_then_else (match_operator 3 "boolean_operator"
+ [(and:SI (not:SI (match_operand:SI 0 "register_operand"
"r"))
+(match_operand:SI 1 "register_operand" "r"))
+(const_int 0)])
+ (label_ref (match_operand 2 "" ""))
+ (pc)))]
+ ""
+{
+ switch (GET_CODE (operands[3]))
+{
+case EQ: return "ball\t%0, %1, %2";
+case NE: return "bnall\t%0, %1, %2";
+default: gcc_unreachable ();
+}
+}
+ [(set_attr "type" "jump")
+ (set_attr "mode" "none")
+ (set_attr "length""3")])
+
;; Zero-overhead looping support.
diff --git a/gcc/testsuite/gcc.target/xtensa/BALL-BNALL.c
b/gcc/testsuite/gcc.target/xtensa/BALL-BNALL.c
new file mode 100644
index 000..ba61c6f371b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/xtensa/BALL-BNALL.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+extern void foo(void);
+
+void BNONE_test(int a, int b)
+{
+ if (a & b)
+foo();
+}
+
+void BANY_test(int a, int b)
+{
+ if (!(a & b))
+foo();
+}
+
+void BALL_test(int a, int b)
+{
+ if (~a & b)
+foo();
+}
+
+void BNALL_test(int a, int b)
+{
+ if (!(~a & b))
+foo();
+}
+
+/* { dg-final { scan-assembler-times "bnone" 1 } } */
+/* { dg-final { scan-assembler-times "bany" 1 } } */
+/* { dg-final { scan-assembler-times "ball" 1 } } */
+/* { dg-final { scan-assembler-times "bnall" 1 } } */
--
2.20.1
