Make performance counters always 64 bits wide (#178)

This prevents the counters from easily overflowing for a 32-bit pk.

1 files changed, 58 insertions, 0 deletions

diff --git a/pk/pk.h b/pk/pk.h
index 1167f6e..a55ab6c 100644
--- a/pk/pk.h
+++ b/pk/pk.h
@@ -41,6 +41,64 @@ static inline int insn_len(long insn)
   return (insn & 0x3) < 0x3 ? 2 : 4;
 }
 
+#if __riscv_xlen == 32
+
+static inline uint64_t rdtime64()
+{
+  uint32_t time;
+  uint32_t timeh1;
+  uint32_t timeh2;
+
+  do
+  {
+    timeh1 = read_csr(timeh);
+    time = read_csr(time);
+    timeh2 = read_csr(timeh);
+  } while(timeh1 != timeh2);
+
+  return (((uint64_t) timeh1) << 32) | time;
+}
+
+static inline uint64_t rdcycle64()
+{
+  uint32_t cycle;
+  uint32_t cycleh1;
+  uint32_t cycleh2;
+
+  do
+  {
+    cycleh1 = read_csr(cycleh);
+    cycle = read_csr(cycle);
+    cycleh2 = read_csr(cycleh);
+  } while(cycleh1 != cycleh2);
+
+  return (((uint64_t) cycleh1) << 32) | cycle;
+}
+
+static inline uint64_t rdinstret64()
+{
+  uint32_t instret;
+  uint32_t instreth1;
+  uint32_t instreth2;
+
+  do
+  {
+    instreth1 = read_csr(instreth);
+    instret = read_csr(instret);
+    instreth2 = read_csr(instreth);
+  } while(instreth1 != instreth2);
+
+  return (((uint64_t) instreth1) << 32) | instret;
+}
+
+#else
+
+#define rdtime64 rdtime
+#define rdcycle64 rdcycle
+#define rdinstret64 rdinstret
+
+#endif
+
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
 
 #ifdef __cplusplus