[PATCH v5 1/1] RISC-V: Add support for XCVbi extension in CV32E40P

Spec: github.com/openhwgroup/core-v-sw/blob/master/specifications/corev-builtin-spec.md

Contributors:
   Mary Bennett <mary.bennett@embecosm.com>
   Nandni Jamnadas <nandni.jamnadas@embecosm.com>
   Pietra Ferreira <pietra.ferreira@embecosm.com>
   Charlie Keaney
   Jessica Mills
   Craig Blackmore <craig.blackmore@embecosm.com>
   Simon Cook <simon.cook@embecosm.com>
   Jeremy Bennett <jeremy.bennett@embecosm.com>
   Helene Chelin <helene.chelin@embecosm.com>

gcc/ChangeLog:
	* common/config/riscv/riscv-common.cc: Create XCVbi extension
	support.
	* config/riscv/riscv.opt: Likewise.
	* config/riscv/corev.md: Implement cv_branch<mode> pattern
	for cv.beqimm and cv.bneimm.
	* config/riscv/riscv.md: Add CORE-V branch immediate to RISC-V
	branch instruction pattern.
	* config/riscv/constraints.md: Implement constraints
	cv_bi_s5 - signed 5-bit immediate.
	* config/riscv/predicates.md: Implement predicate
	const_int5s_operand - signed 5 bit immediate.
	* doc/sourcebuild.texi: Add XCVbi documentation.

gcc/testsuite/ChangeLog:
	* gcc.target/riscv/cv-bi-beqimm-compile-1.c: New test.
	* gcc.target/riscv/cv-bi-beqimm-compile-2.c: New test.
	* gcc.target/riscv/cv-bi-bneimm-compile-1.c: New test.
	* gcc.target/riscv/cv-bi-bneimm-compile-2.c: New test.
	* lib/target-supports.exp: Add proc for XCVbi.

12 files changed, 198 insertions, 1 deletions

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 48efef4..440127a 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -366,6 +366,7 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
   {"xcvalu", ISA_SPEC_CLASS_NONE, 1, 0},
   {"xcvelw", ISA_SPEC_CLASS_NONE, 1, 0},
   {"xcvsimd", ISA_SPEC_CLASS_NONE, 1, 0},
+  {"xcvbi", ISA_SPEC_CLASS_NONE, 1, 0},
 
   {"xtheadba", ISA_SPEC_CLASS_NONE, 1, 0},
   {"xtheadbb", ISA_SPEC_CLASS_NONE, 1, 0},
@@ -1618,6 +1619,7 @@ static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
   {"xcvalu",        &gcc_options::x_riscv_xcv_subext, MASK_XCVALU},
   {"xcvelw",        &gcc_options::x_riscv_xcv_subext, MASK_XCVELW},
   {"xcvsimd",       &gcc_options::x_riscv_xcv_subext, MASK_XCVSIMD},
+  {"xcvbi",         &gcc_options::x_riscv_xcv_subext, MASK_XCVBI},
 
   {"xtheadba",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBA},
   {"xtheadbb",      &gcc_options::x_riscv_xthead_subext, MASK_XTHEADBB},
diff --git a/gcc/config/riscv/constraints.md b/gcc/config/riscv/constraints.md
index 41acaea..972e884 100644
--- a/gcc/config/riscv/constraints.md
+++ b/gcc/config/riscv/constraints.md
@@ -268,6 +268,12 @@
        (and (match_test "IN_RANGE (ival, 0, 1073741823)")
             (match_test "exact_log2 (ival + 1) != -1"))))
 
+(define_constraint "CV_bi_sign5"
+  "@internal
+   A 5-bit signed immediate for CORE-V Immediate Branch."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, -16, 15)")))
+
 (define_constraint "CV_simd_si6"
   "A 6-bit signed immediate for SIMD."
   (and (match_code "const_int")
diff --git a/gcc/config/riscv/corev.md b/gcc/config/riscv/corev.md
index 3857c53..e2db8f3 100644
--- a/gcc/config/riscv/corev.md
+++ b/gcc/config/riscv/corev.md
@@ -2614,3 +2614,40 @@
 	 cv.subrotmj.div8\t%0,%1,%2"
 	[(set_attr "type" "arith")
 	(set_attr "mode" "SI")])
+
+;; XCVBI Instructions
+(define_insn "*cv_branch<mode>"
+  [(set (pc)
+	(if_then_else
+	 (match_operator 1 "equality_operator"
+			 [(match_operand:X 2 "register_operand" "r")
+			  (match_operand:X 3 "const_int5s_operand" "CV_bi_sign5")])
+	 (label_ref (match_operand 0 "" ""))
+	 (pc)))]
+  "TARGET_XCVBI"
+{
+  if (get_attr_length (insn) == 12)
+    return "cv.b%N1\t%2,%z3,1f; jump\t%l0,ra; 1:";
+
+  return "cv.b%C1imm\t%2,%3,%0";
+}
+  [(set_attr "type" "branch")
+   (set_attr "mode" "none")])
+
+(define_insn "*branch<mode>"
+  [(set (pc)
+        (if_then_else
+         (match_operator 1 "ordered_comparison_operator"
+                         [(match_operand:X 2 "register_operand" "r")
+                          (match_operand:X 3 "reg_or_0_operand" "rJ")])
+         (label_ref (match_operand 0 "" ""))
+         (pc)))]
+  "TARGET_XCVBI"
+{
+  if (get_attr_length (insn) == 12)
+    return "b%N1\t%2,%z3,1f; jump\t%l0,ra; 1:";
+
+  return "b%C1\t%2,%z3,%l0";
+}
+  [(set_attr "type" "branch")
+   (set_attr "mode" "none")])
diff --git a/gcc/config/riscv/predicates.md b/gcc/config/riscv/predicates.md
index 6c87a7b..539e0f7 100644
--- a/gcc/config/riscv/predicates.md
+++ b/gcc/config/riscv/predicates.md
@@ -445,6 +445,10 @@
   (ior (match_operand 0 "const_int6_operand")
        (match_operand 0 "register_operand")))
 
+(define_predicate "const_int5s_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), -16, 15)")))
+
 ;; Predicates for the V extension.
 (define_special_predicate "vector_length_operand"
   (ior (match_operand 0 "pmode_register_operand")
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index f433b038..0346cc3 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -2756,7 +2756,7 @@
 			  (match_operand:X 3 "reg_or_0_operand" "rJ")])
 	 (label_ref (match_operand 0 "" ""))
 	 (pc)))]
-  ""
+  "!TARGET_XCVBI"
 {
   if (get_attr_length (insn) == 12)
     return "b%N1\t%2,%z3,1f; jump\t%l0,ra; 1:";
diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index 45a9517..710c0a4 100644
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -430,6 +430,8 @@ Mask(ZCMP) Var(riscv_zc_subext)
 
 Mask(ZCMT) Var(riscv_zc_subext)
 
+Mask(XCVBI) Var(riscv_xcv_subext)
+
 TargetVariable
 int riscv_sv_subext
 
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index efab862..7ef82fc 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2507,6 +2507,9 @@ Test system has an integer register width of 32 bits.
 @item rv64
 Test system has an integer register width of 64 bits.
 
+@item cv_bi
+Test system has support for the CORE-V BI extension.
+
 @end table
 
 @subsubsection CORE-V specific attributes
diff --git a/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-1.c b/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-1.c
new file mode 100644
index 0000000..5b6ba5b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-1.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target cv_bi } */
+/* { dg-options "-march=rv32i_xcvbi -mabi=ilp32" } */
+/* { dg-skip-if "" { *-*-* }  { "-O0" } { "" } } */
+
+/* __builtin_expect is used to provide the compiler with
+   branch prediction information and to direct the compiler
+   to the expected flow through the code.  */
+
+int
+foo1 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 12);
+    return a != 10 ? x : y;
+}
+
+/* { dg-final { scan-assembler-times "cv\\.beqimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),10,\(\?\:.L\[0-9\]\)" 1 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-2.c b/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-2.c
new file mode 100644
index 0000000..bb2e584
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/cv-bi-beqimm-compile-2.c
@@ -0,0 +1,48 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target cv_bi } */
+/* { dg-options "-march=rv32i_xcvbi -mabi=ilp32" } */
+/* { dg-skip-if "" { *-*-* }  { "-O0" } { "" } } */
+
+/* __builtin_expect is used to provide the compiler with
+   branch prediction information and to direct the compiler
+   to the expected flow through the code.  */
+
+int
+foo1 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 10);
+    return a != -16 ? x : y;
+}
+
+int
+foo2 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 10);
+    return a != 0 ? x : y;
+}
+
+int
+foo3 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 10);
+    return a != 15 ? x : y;
+}
+
+int
+foo4 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 10);
+    return a != -17 ? x : y;
+}
+
+int
+foo5 (int a, int x, int y)
+{
+    a = __builtin_expect (a, 10);
+    return a != 16 ? x : y;
+}
+
+/* { dg-final { scan-assembler-times "cv\\.beqimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),-16,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "cv\\.beqimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),0,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "cv\\.beqimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),15,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "beq\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),\(\?\:.L\[0-9\]+\)" 2 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-1.c b/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-1.c
new file mode 100644
index 0000000..21eab38
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-1.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target cv_bi } */
+/* { dg-options "-march=rv32i_xcvbi -mabi=ilp32" } */
+/* { dg-skip-if "" { *-*-* }  { "-O0" } { "" } } */
+
+/* __builtin_expect is used to provide the compiler with
+   branch prediction information and to direct the compiler
+   to the expected flow through the code.  */
+
+int
+foo1(int a, int x, int y)
+{
+    a = __builtin_expect(a, 10);
+    return a == 10 ? x : y;
+}
+
+/* { dg-final { scan-assembler-times "cv\\.bneimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),10,\(\?\:.L\[0-9\]\)" 1 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-2.c b/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-2.c
new file mode 100644
index 0000000..a028f68
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/cv-bi-bneimm-compile-2.c
@@ -0,0 +1,48 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target cv_bi } */
+/* { dg-options "-march=rv32i_xcvbi -mabi=ilp32" } */
+/* { dg-skip-if "" { *-*-* }  { "-O0" } { "" } } */
+
+/* __builtin_expect is used to provide the compiler with
+   branch prediction information and to direct the compiler
+   to the expected flow through the code.  */
+
+int
+foo1(int a, int x, int y)
+{
+    a = __builtin_expect(a, -16);
+    return a == -16 ? x : y;
+}
+
+int
+foo2(int a, int x, int y)
+{
+    a = __builtin_expect(a, 0);
+    return a == 0 ? x : y;
+}
+
+int
+foo3(int a, int x, int y)
+{
+    a = __builtin_expect(a, 15);
+    return a == 15 ? x : y;
+}
+
+int
+foo4(int a, int x, int y)
+{
+    a = __builtin_expect(a, -17);
+    return a == -17 ? x : y;
+}
+
+int
+foo5(int a, int x, int y)
+{
+    a = __builtin_expect(a, 16);
+    return a == 16 ? x : y;
+}
+
+/* { dg-final { scan-assembler-times "cv\\.bneimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),-16,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "cv\\.bneimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),0,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "cv\\.bneimm\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),15,\(\?\:.L\[0-9\]\)" 1 } } */
+/* { dg-final { scan-assembler-times "bne\t\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),\(\?\:t\[0-6\]\|a\[0-7\]\|s\[1-11\]\),\(\?\:.L\[0-9\]+\)" 2 } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 467b539..3262104 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -13375,6 +13375,19 @@ proc check_effective_target_cv_simd { } {
     } "-march=rv32i_xcvsimd" ]
 }
 
+# Return 1 if the CORE-V BI extension is available
+proc check_effective_target_cv_bi { } {
+    if { !([istarget riscv*-*-*]) } {
+         return 0
+     }
+    return [check_no_compiler_messages cv_bi object {
+        void foo (void)
+        {
+          asm ("cv.beqimm t0, -16, foo");
+        }
+    } "-march=rv32i_xcvbi" ]
+}
+
 proc check_effective_target_loongarch_sx { } {
     return [check_no_compiler_messages loongarch_lsx assembly {
        #if !defined(__loongarch_sx)