LoongArch: Expand left rotate to right rotate with negated amount

gcc/ChangeLog:

	* config/loongarch/loongarch.md (rotl<mode>3):
	New define_expand.
	* config/loongarch/simd.md (vrotl<mode>3): Likewise.
	(rotl<mode>3): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/rotl-with-rotr.c: New test.
	* gcc.target/loongarch/rotl-with-vrotr-b.c: New test.
	* gcc.target/loongarch/rotl-with-vrotr-h.c: New test.
	* gcc.target/loongarch/rotl-with-vrotr-w.c: New test.
	* gcc.target/loongarch/rotl-with-vrotr-d.c: New test.
	* gcc.target/loongarch/rotl-with-xvrotr-b.c: New test.
	* gcc.target/loongarch/rotl-with-xvrotr-h.c: New test.
	* gcc.target/loongarch/rotl-with-xvrotr-w.c: New test.
	* gcc.target/loongarch/rotl-with-xvrotr-d.c: New test.

11 files changed, 127 insertions, 0 deletions

diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md
index 2b0609f..e56ea71 100644
--- a/gcc/config/loongarch/loongarch.md
+++ b/gcc/config/loongarch/loongarch.md
@@ -2903,6 +2903,18 @@
   [(set_attr "type" "shift,shift")
    (set_attr "mode" "SI")])
 
+;; Expand left rotate to right rotate.
+(define_expand "rotl<mode>3"
+  [(set (match_dup 3)
+	(neg:SI (match_operand:SI 2 "register_operand")))
+   (set (match_operand:GPR 0 "register_operand")
+	(rotatert:GPR (match_operand:GPR 1 "register_operand")
+		      (match_dup 3)))]
+  ""
+  {
+    operands[3] = gen_reg_rtx (SImode);
+  });
+
 ;; The following templates were added to generate "bstrpick.d + alsl.d"
 ;; instruction pairs.
 ;; It is required that the values of const_immalsl_operand and
diff --git a/gcc/config/loongarch/simd.md b/gcc/config/loongarch/simd.md
index 13202f7..93fb39a 100644
--- a/gcc/config/loongarch/simd.md
+++ b/gcc/config/loongarch/simd.md
@@ -268,6 +268,35 @@
   [(set_attr "type" "simd_int_arith")
    (set_attr "mode" "<MODE>")])
 
+;; Expand left rotate to right rotate.
+(define_expand "vrotl<mode>3"
+  [(set (match_dup 3)
+	(neg:IVEC (match_operand:IVEC 2 "register_operand")))
+   (set (match_operand:IVEC 0 "register_operand")
+	(rotatert:IVEC (match_operand:IVEC 1 "register_operand")
+		       (match_dup 3)))]
+  ""
+  {
+    operands[3] = gen_reg_rtx (<MODE>mode);
+  });
+
+;; Expand left rotate with a scalar amount to right rotate: negate the
+;; scalar before broadcasting it because scalar negation is cheaper than
+;; vector negation.
+(define_expand "rotl<mode>3"
+  [(set (match_dup 3)
+	(neg:SI (match_operand:SI 2 "register_operand")))
+   (set (match_dup 4)
+	(vec_duplicate:IVEC (subreg:<IVEC:UNITMODE> (match_dup 3) 0)))
+   (set (match_operand:IVEC 0 "register_operand")
+	(rotatert:IVEC (match_operand:IVEC 1 "register_operand")
+		       (match_dup 4)))]
+  ""
+  {
+    operands[3] = gen_reg_rtx (SImode);
+    operands[4] = gen_reg_rtx (<MODE>mode);
+  });
+
 ;; <x>vrotri.{b/h/w/d}
 
 (define_insn "rotr<mode>3"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-rotr.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-rotr.c
new file mode 100644
index 0000000..84cc53c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-rotr.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler "rotr\\.w" } } */
+
+unsigned
+t (unsigned a, unsigned b)
+{
+  return a << b | a >> (32 - b);
+}
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-b.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-b.c
new file mode 100644
index 0000000..14298bf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-b.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlsx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "vrotr\\.b" 2 } } */
+/* { dg-final { scan-assembler-times "vneg\\.b" 1 } } */
+
+#define TYPE char
+#include "rotl-with-vrotr-w.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-d.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-d.c
new file mode 100644
index 0000000..0e971b3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-d.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlsx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "vrotr\\.d" 2 } } */
+/* { dg-final { scan-assembler-times "vneg\\.d" 1 } } */
+
+#define TYPE long long
+#include "rotl-with-vrotr-w.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-h.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-h.c
new file mode 100644
index 0000000..93216eb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-h.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlsx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "vrotr\\.h" 2 } } */
+/* { dg-final { scan-assembler-times "vneg\\.h" 1 } } */
+
+#define TYPE short
+#include "rotl-with-vrotr-w.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-w.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-w.c
new file mode 100644
index 0000000..d05b86f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-vrotr-w.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlsx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "vrotr\\.w" 2 } } */
+/* { dg-final { scan-assembler-times "vneg\\.w" 1 } } */
+
+#ifndef VLEN
+#define VLEN 16
+#endif
+
+#ifndef TYPE
+#define TYPE int
+#endif
+
+typedef unsigned TYPE V __attribute__ ((vector_size (VLEN)));
+V a, b, c;
+
+void
+test (int x)
+{
+  b = a << x | a >> ((int)sizeof (TYPE) * __CHAR_BIT__ - x);
+}
+
+void
+test2 (void)
+{
+  for (int i = 0; i < VLEN / sizeof (TYPE); i++)
+    c[i] = a[i] << b[i] | a[i] >> ((int)sizeof (TYPE) * __CHAR_BIT__ - b[i]);
+}
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-b.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-b.c
new file mode 100644
index 0000000..2674b1b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-b.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlasx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "xvrotr\\.b" 2 } } */
+/* { dg-final { scan-assembler-times "xvneg\\.b" 1 } } */
+
+#define VLEN 32
+#include "rotl-with-vrotr-b.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-d.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-d.c
new file mode 100644
index 0000000..e944033
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-d.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlasx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "xvrotr\\.d" 2 } } */
+/* { dg-final { scan-assembler-times "xvneg\\.d" 1 } } */
+
+#define VLEN 32
+#include "rotl-with-vrotr-d.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-h.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-h.c
new file mode 100644
index 0000000..3d99894
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-h.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlasx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "xvrotr\\.h" 2 } } */
+/* { dg-final { scan-assembler-times "xvneg\\.h" 1 } } */
+
+#define VLEN 32
+#include "rotl-with-vrotr-h.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-w.c b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-w.c
new file mode 100644
index 0000000..ca6aa7b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/rotl-with-xvrotr-w.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlasx -fno-vect-cost-model" } */
+/* { dg-final { scan-assembler-times "xvrotr\\.w" 2 } } */
+/* { dg-final { scan-assembler-times "xvneg\\.w" 1 } } */
+
+#define VLEN 32
+#include "rotl-with-vrotr-w.c"