RISC-V: Add C API and hwprobe feature bit for zicfiss

riscv-c-api-doc PR #187 defines the RISC-V C API feature bit
for zicfiss as group 1, bit 27.  GCC already supports zicfiss,
so add the missing feature-bit metadata and libgcc copy of the
definition.

Upstream Linux exposes zicfiss through RISCV_HWPROBE_KEY_IMA_EXT_1.
Copy the upstream Linux hwprobe constants and map the zicfiss bit
directly to the matching feature bit.

This patch only adds metadata and runtime feature-bit probing.  It
does not add ISA extension support.

gcc/ChangeLog:

	* common/config/riscv/riscv-ext-bitmask.def: Add zicfiss.
	* config/riscv/riscv-ext.def: Add C API bit position for
	zicfiss.

libgcc/ChangeLog:

	* config/riscv/feature_bits.c (ZICFISS_GROUPID,
	ZICFISS_BITMASK, RISCV_HWPROBE_KEY_IMA_EXT_1,
	RISCV_HWPROBE_EXT_ZICFISS): Define.
	(SET_FROM_IMA_EXT_1): Define.
	(__init_riscv_features_bits_linux): Query IMA_EXT_1 and set
	zicfiss from the corresponding upstream Linux hwprobe bit.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

diff --git a/gcc/common/config/riscv/riscv-ext-bitmask.def b/gcc/common/config/riscv/riscv-ext-bitmask.def
index 315ae8fde08a90661525c01f3438808f477e2c21..be12e4bea72d9c01c51b3f003fddb5093c810cdd 100644 (file)
--- a/gcc/common/config/riscv/riscv-ext-bitmask.def
+++ b/gcc/common/config/riscv/riscv-ext-bitmask.def
@@ -98,6 +98,7 @@ RISCV_EXT_BITMASK ("zicbop",          1, 25)
 RISCV_EXT_BITMASK ("zilsd",            1,  8)
 RISCV_EXT_BITMASK ("zclsd",            1,  9)
 RISCV_EXT_BITMASK ("zicfilp",          1, 26)
+RISCV_EXT_BITMASK ("zicfiss",          1, 27)
 RISCV_EXT_BITMASK ("zcmp",             1, 10)
 RISCV_EXT_BITMASK ("zifencei",         1, 11)
 

diff --git a/gcc/config/riscv/riscv-ext.def b/gcc/config/riscv/riscv-ext.def
index bfa27e725153b341b0928f5dd051eb33728f53cb..71d34470848b7da2c01b9bfba01dadf65eb087a6 100644 (file)
--- a/gcc/config/riscv/riscv-ext.def
+++ b/gcc/config/riscv/riscv-ext.def
@@ -346,8 +346,8 @@ DEFINE_RISCV_EXT(
   /* DEP_EXTS */ ({"zicsr", "zimop"}),
   /* SUPPORTED_VERSIONS */ ({{1, 0}}),
   /* FLAG_GROUP */ zi,
-  /* BITMASK_GROUP_ID */ BITMASK_NOT_YET_ALLOCATED,
-  /* BITMASK_BIT_POSITION*/ BITMASK_NOT_YET_ALLOCATED,
+  /* BITMASK_GROUP_ID */ 1,
+  /* BITMASK_BIT_POSITION*/ 27,
   /* EXTRA_EXTENSION_FLAGS */ 0)
 
 DEFINE_RISCV_EXT(

diff --git a/libgcc/config/riscv/feature_bits.c b/libgcc/config/riscv/feature_bits.c
index 367473050b4236e3286e9be2c6e80b55babd1178..8d226502eb7a897016452159ffd1893e5abb4e86 100644 (file)
--- a/libgcc/config/riscv/feature_bits.c
+++ b/libgcc/config/riscv/feature_bits.c
@@ -184,6 +184,8 @@ struct {
 #define ZICBOP_BITMASK (1ULL << 25)
 #define ZICFILP_GROUPID 1
 #define ZICFILP_BITMASK (1ULL << 26)
+#define ZICFISS_GROUPID 1
+#define ZICFISS_BITMASK (1ULL << 27)
 
 #define SET_EXT(EXT) features[EXT##_GROUPID] |= EXT##_BITMASK
 
@@ -268,6 +270,8 @@ struct {
 #define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
 #define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
 #define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
+#define RISCV_HWPROBE_KEY_IMA_EXT_1 16
+#define RISCV_HWPROBE_EXT_ZICFISS (1ULL << 0)
 
 struct riscv_hwprobe {
   long long key;
@@ -297,6 +301,9 @@ static long syscall_5_args (long number, long arg1, long arg2, long arg3,
 #define SET_FROM_IMA_EXT(EXT) \
   SET_FROM_HWPROBE (hwprobe_ima_ext, EXT)
 
+#define SET_FROM_IMA_EXT_1(EXT) \
+  SET_FROM_HWPROBE (hwprobe_ima_ext_1, EXT)
+
 static void __init_riscv_features_bits_linux ()
 {
   struct riscv_hwprobe hwprobes[] = {
@@ -305,6 +312,7 @@ static void __init_riscv_features_bits_linux ()
     {RISCV_HWPROBE_KEY_MIMPID, 0},
     {RISCV_HWPROBE_KEY_BASE_BEHAVIOR, 0},
     {RISCV_HWPROBE_KEY_IMA_EXT_0, 0},
+    {RISCV_HWPROBE_KEY_IMA_EXT_1, 0},
   };
 
   long res = syscall_5_args (__NR_riscv_hwprobe, (long)&hwprobes,
@@ -443,6 +451,9 @@ static void __init_riscv_features_bits_linux ()
   SET_FROM_IMA_EXT (ZCLSD);
   SET_FROM_IMA_EXT (ZICFILP);
 
+  const struct riscv_hwprobe hwprobe_ima_ext_1 = hwprobes[5];
+  SET_FROM_IMA_EXT_1 (ZICFISS);
+
   for (i = 0; i < RISCV_FEATURE_BITS_LENGTH; ++i)
     __riscv_feature_bits.features[i] = features[i];