@@ -285,3 +285,26 @@
(ior (match_operand 0 "register_operand")
(match_test "GET_CODE (op) == UNSPEC
&& (XINT (op, 1) == UNSPEC_VUNDEF)"))))
+
+;; A CONST_INT operand that consists of a single run of 32 consecutive
+;; set bits.
+(define_predicate "consecutive_bits32_operand"
+ (and (match_operand 0 "consecutive_bits_operand")
+ (match_test "popcount_hwi (UINTVAL (op)) == 32")))
+
+;; A CONST_INT operand that, if shifted down to start with its least
+;; significant non-zero bit, is a SMALL_OPERAND (suitable as an
+;; immediate to logical and arithmetic instructions).
+(define_predicate "shifted_const_arith_operand"
+ (and (match_code "const_int")
+ (match_test "ctz_hwi (INTVAL (op)) > 0")
+ (match_test "SMALL_OPERAND (INTVAL (op) >> ctz_hwi (INTVAL (op)))")))
+
+;; A CONST_INT operand that fits into the unsigned half of a
+;; signed-immediate after the top bit has been cleared.
+(define_predicate "uimm_extra_bit_operand"
+ (and (match_code "const_int")
+ (not (and (match_test "SMALL_OPERAND (INTVAL (op))")
+ (match_test "INTVAL (op) > 0")))
+ (ior (match_test "SMALL_OPERAND (UINTVAL (op) & ~(HOST_WIDE_INT_1U << floor_log2 (UINTVAL (op))))")
+ (match_test "popcount_hwi (UINTVAL (op)) == 2"))))
@@ -2205,6 +2205,57 @@
;; Conditional branches
+(define_insn_and_split "*branch<ANYI:mode>_shiftedarith_equals_zero"
+ [(set (pc)
+ (if_then_else (match_operator 1 "equality_operator"
+ [(and:ANYI (match_operand:ANYI 2 "register_operand" "r")
+ (match_operand 3 "shifted_const_arith_operand" "i"))
+ (const_int 0)])
+ (label_ref (match_operand 0 "" ""))
+ (pc)))
+ (clobber (match_scratch:ANYI 4 "=&r"))]
+ "INTVAL (operands[3]) >= 0 || !partial_subreg_p (operands[2])"
+ "#"
+ "&& reload_completed"
+ [(set (match_dup 4) (lshiftrt:ANYI (match_dup 2) (match_dup 6)))
+ (set (match_dup 4) (and:ANYI (match_dup 4) (match_dup 7)))
+ (set (pc) (if_then_else (match_op_dup 1 [(match_dup 4) (const_int 0)])
+ (label_ref (match_dup 0)) (pc)))]
+{
+ HOST_WIDE_INT mask = INTVAL (operands[3]);
+ int trailing = ctz_hwi (mask);
+
+ operands[6] = GEN_INT (trailing);
+ operands[7] = GEN_INT (mask >> trailing);
+})
+
+(define_insn_and_split "*branch<ANYI:mode>_shiftedmask_equals_zero"
+ [(set (pc)
+ (if_then_else (match_operator 1 "equality_operator"
+ [(and:ANYI (match_operand:ANYI 2 "register_operand" "r")
+ (match_operand 3 "consecutive_bits_operand" "i"))
+ (const_int 0)])
+ (label_ref (match_operand 0 "" ""))
+ (pc)))
+ (clobber (match_scratch:X 4 "=&r"))]
+ "(INTVAL (operands[3]) >= 0 || !partial_subreg_p (operands[2]))
+ && popcount_hwi (INTVAL (operands[3])) > 1
+ && !SMALL_OPERAND (INTVAL (operands[3]))"
+ "#"
+ "&& reload_completed"
+ [(set (match_dup 4) (ashift:X (subreg:X (match_dup 2) 0) (match_dup 6)))
+ (set (match_dup 4) (lshiftrt:X (match_dup 4) (match_dup 7)))
+ (set (pc) (if_then_else (match_op_dup 1 [(match_dup 4) (const_int 0)])
+ (label_ref (match_dup 0)) (pc)))]
+{
+ unsigned HOST_WIDE_INT mask = INTVAL (operands[3]);
+ int leading = clz_hwi (mask);
+ int trailing = ctz_hwi (mask);
+
+ operands[6] = GEN_INT (leading);
+ operands[7] = GEN_INT (leading + trailing);
+})
+
(define_insn "*branch<mode>_equals_zero"
[(set (pc)
(if_then_else
new file mode 100644
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc -mabi=lp64" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-O1" } } */
+
+void g();
+
+void f(long long a)
+{
+ if (a & 0xff00)
+ g();
+}
+
+void f2(long long a)
+{
+ if (a & (-4ull << 3))
+ g();
+}
+
+void f3(long long a)
+{
+ if (a & 0xffff00)
+ g();
+}
+
+void f4(long long a)
+{
+ if (a & 0x7ff800)
+ g();
+}
+
+/* { dg-final { scan-assembler-times "slli\t" 2 } } */
+/* { dg-final { scan-assembler-times "srli\t" 3 } } */
+/* { dg-final { scan-assembler-times "andi\t" 1 } } */
+/* { dg-final { scan-assembler-times "\tli\t" 1 } } */
+/* { dg-final { scan-assembler-not "addi\t" } } */
+/* { dg-final { scan-assembler-not "and\t" } } */
+
gcc/ChangeLog: * config/riscv/predicates.md (shifted_const_arith_operand): (uimm_extra_bit_operand): * config/riscv/riscv.md (*branch<ANYI:mode>_shiftedarith_equals_zero): (*branch<ANYI:mode>_shiftedmask_equals_zero): gcc/testsuite/ChangeLog: * gcc.target/riscv/branch-1.c: New test. Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> --- gcc/config/riscv/predicates.md | 23 ++++++++++ gcc/config/riscv/riscv.md | 51 +++++++++++++++++++++++ gcc/testsuite/gcc.target/riscv/branch-1.c | 37 ++++++++++++++++ 3 files changed, 111 insertions(+) create mode 100644 gcc/testsuite/gcc.target/riscv/branch-1.c