在 2026/5/19 上午10:54, Xi Ruoyao 写道:
r17-523 has added the __builtin_bitreverse{8,16,32,64} builtins and
established that the standard optab names for them are
bitreverse<mode>2. Rename the rbit<mode> expanders so they'll be used
for those builtins.
r17-567 has already removed the uses of rbit<mode> so the old names do
not need to be kept.
PR target/50481
gcc/
* config/loongarch/loongarch.md (@rbit<GPR:mode>2): Rename to
...
(@bitreverse<mode>2): ... this.
(rbithi2): Rename to ...
(bitreversehi2): ... this.
(rbitqi2): Rename to ...
(bitreverseqi2): ... this.
(rbitsi_extended): Rename to ...
(bitreversesi2_extended): ... this.
gcc/testsuite/
* gcc.target/loongarch/la64/bitreverse.c: New test.
---
Bootstrapped and regtested on loongarch64-linux-gnu. Ok for trunk?
I have no questions now.
Thanks!
gcc/config/loongarch/loongarch.md | 17 ++---
.../gcc.target/loongarch/la64/bitreverse.c | 73 +++++++++++++++++++
2 files changed, 81 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/loongarch/la64/bitreverse.c
diff --git a/gcc/config/loongarch/loongarch.md
b/gcc/config/loongarch/loongarch.md
index 297c7e41492..fe6d28e7616 100644
--- a/gcc/config/loongarch/loongarch.md
+++ b/gcc/config/loongarch/loongarch.md
@@ -4741,7 +4741,7 @@ (define_insn "bitrev_8b"
[(set_attr "type" "unknown")
(set_attr "mode" "DI")])
-(define_insn "@rbit<mode>"
+(define_insn "@bitreverse<mode>2"
[(set (match_operand:GPR 0 "register_operand" "=r")
(bitreverse:GPR (match_operand:GPR 1 "register_operand" "r")))]
"TARGET_64BIT || TARGET_32BIT_S"
@@ -4749,7 +4749,7 @@ (define_insn "@rbit<mode>"
[(set_attr "type" "unknown")
(set_attr "mode" "<MODE>")])
-(define_insn "rbitsi_extended"
+(define_insn "bitreversesi2_extended"
[(set (match_operand:DI 0 "register_operand" "=r")
(sign_extend:DI
(bitreverse:SI (match_operand:SI 1 "register_operand" "r"))))]
@@ -4760,7 +4760,7 @@ (define_insn "rbitsi_extended"
;; If we don't care high bits, bitrev.4b can reverse bits of values in
;; QImode.
-(define_insn "rbitqi"
+(define_insn "bitreverseqi2"
[(set (match_operand:QI 0 "register_operand" "=r")
(bitreverse:QI (match_operand:QI 1 "register_operand" "r")))]
"TARGET_64BIT || TARGET_32BIT_S"
@@ -4768,18 +4768,17 @@ (define_insn "rbitqi"
[(set_attr "type" "unknown")
(set_attr "mode" "SI")])
-;; For HImode it's a little complicated...
-(define_expand "rbithi"
- [(match_operand:HI 0 "register_operand")
- (match_operand:HI 1 "register_operand")]
+(define_expand "bitreversehi2"
+ [(set (match_operand:HI 0 "register_operand" "=r")
+ (bitreverse:HI (match_operand:HI 1 "register_operand" "r")))]
""
{
rtx t = gen_reg_rtx (word_mode);
/* Oh, using paradoxical subreg. I learnt the trick from RISC-V,
hoping we won't be blown up altogether one day. */
- emit_insn (gen_rbit(word_mode, t,
- gen_lowpart (word_mode, operands[1])));
+ emit_insn (gen_bitreverse2 (word_mode, t,
+ gen_lowpart (word_mode, operands[1])));
t = expand_simple_binop (word_mode, LSHIFTRT, t,
GEN_INT (GET_MODE_BITSIZE (word_mode) - 16),
NULL_RTX, false, OPTAB_DIRECT);
diff --git a/gcc/testsuite/gcc.target/loongarch/la64/bitreverse.c
b/gcc/testsuite/gcc.target/loongarch/la64/bitreverse.c
new file mode 100644
index 00000000000..c59bb5b6df7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/la64/bitreverse.c
@@ -0,0 +1,73 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" "" } } */
+
+/*
+** t1:
+** bitrev\.d \$r4,\$r4
+** jr \$r1
+*/
+long
+t1 (long x)
+{
+ return __builtin_bitreverse64 (x);
+}
+
+/*
+** t2:
+** bitrev\.w \$r4,\$r4
+** jr \$r1
+*/
+int
+t2 (int x)
+{
+ return __builtin_bitreverse32 (x);
+}
+
+/*
+** t3:
+** bitrev\.d (\$r[0-9]+),\$r4
+** srai\.d \$r4,\1,48
+** jr \$r1
+*/
+short
+t3 (short x)
+{
+ return __builtin_bitreverse16 (x);
+}
+
+/*
+** t4:
+** bitrev\.4b (\$r[0-9]+),\$r4
+** ext\.w\.b \$r4,\1
+** jr \$r1
+*/
+char
+t4 (char x)
+{
+ return __builtin_bitreverse8 (x);
+}
+
+/*
+** t5:
+** bitrev\.d (\$r[0-9]+),\$r4
+** srli\.d \$r4,\1,48
+** jr \$r1
+*/
+unsigned short
+t5 (short x)
+{
+ return __builtin_bitreverse16 (x);
+}
+
+/*
+** t6:
+** bitrev\.4b (\$r[0-9]+),\$r4
+** bstrpick\.w \$r4,\1,7,0
+** jr \$r1
+*/
+unsigned char
+t6 (char x)
+{
+ return __builtin_bitreverse8 (x);
+}
