add support for overlap instructions

* add DECLARE_OVERLAP_INSN to bind instructions with extension
* add overlap_list.h to contain the declare of all overlapping instructions
* make func function for overlapping instruction return NULL when the coresponding
extension(s) is not supported.

Author: Weiwei Li

customext/cflush.cc

@@ -24,9 +24,9 @@ class cflush_t : public extension_t
 
   std::vector<insn_desc_t> get_instructions() {
     std::vector<insn_desc_t> insns;
-    insns.push_back((insn_desc_t){0xFC000073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
-    insns.push_back((insn_desc_t){0xFC200073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
-    insns.push_back((insn_desc_t){0xFC100073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){true, 0xFC000073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){true, 0xFC200073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){true, 0xFC100073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
     return insns;
   }
 

riscv/overlap_list.h

@@ -0,0 +1,8 @@
+DECLARE_OVERLAP_INSN(c_fsdsp, 'C')
+DECLARE_OVERLAP_INSN(c_fsdsp, 'D')
+DECLARE_OVERLAP_INSN(c_fld, 'C')
+DECLARE_OVERLAP_INSN(c_fld, 'D')
+DECLARE_OVERLAP_INSN(c_fldsp, 'C')
+DECLARE_OVERLAP_INSN(c_fldsp, 'D')
+DECLARE_OVERLAP_INSN(c_fsd, 'C')
+DECLARE_OVERLAP_INSN(c_fsd, 'D')

riscv/processor.cc

@@ -942,16 +942,23 @@ void processor_t::register_extension(extension_t* x)
 void processor_t::register_base_instructions()
 {
   #define DECLARE_INSN(name, match, mask) \
-    insn_bits_t name##_match = (match), name##_mask = (mask);
+    insn_bits_t name##_match = (match), name##_mask = (mask); \
+    bool name##_supported = true;
+
   #include "encoding.h"
   #undef DECLARE_INSN
 
+  #define DECLARE_OVERLAP_INSN(name, ext) { name##_supported &= isa->extension_enabled(ext); }
+  #include "overlap_list.h"
+  #undef DECLARE_OVERLAP_INSN
+
   #define DEFINE_INSN(name) \
     extern reg_t rv32i_##name(processor_t*, insn_t, reg_t); \
     extern reg_t rv64i_##name(processor_t*, insn_t, reg_t); \
     extern reg_t rv32e_##name(processor_t*, insn_t, reg_t); \
     extern reg_t rv64e_##name(processor_t*, insn_t, reg_t); \
     register_insn((insn_desc_t) { \
+      name##_supported, \
       name##_match, \
       name##_mask, \
       rv32i_##name, \

riscv/processor.h

@@ -29,6 +29,7 @@ reg_t illegal_instruction(processor_t* p, insn_t insn, reg_t pc);
 
 struct insn_desc_t
 {
+  bool supported;
   insn_bits_t match;
   insn_bits_t mask;
   insn_func_t rv32i;
@@ -38,6 +39,9 @@ struct insn_desc_t
 
   insn_func_t func(int xlen, bool rve)
   {
+    if (!supported)
+      return NULL;
+
     if (rve)
       return xlen == 64 ? rv64e : rv32e;
     else
@@ -46,7 +50,7 @@ struct insn_desc_t
 
   static insn_desc_t illegal()
   {
-    return {0, 0, &illegal_instruction, &illegal_instruction, &illegal_instruction, &illegal_instruction};
+    return {true, 0, 0, &illegal_instruction, &illegal_instruction, &illegal_instruction, &illegal_instruction};
   }
 };
 

riscv/rocc.cc

@@ -32,10 +32,10 @@ customX(3)
 std::vector<insn_desc_t> rocc_t::get_instructions()
 {
   std::vector<insn_desc_t> insns;
-  insns.push_back((insn_desc_t){0x0b, 0x7f, &::illegal_instruction, c0, &::illegal_instruction, c0});
-  insns.push_back((insn_desc_t){0x2b, 0x7f, &::illegal_instruction, c1, &::illegal_instruction, c1});
-  insns.push_back((insn_desc_t){0x5b, 0x7f, &::illegal_instruction, c2, &::illegal_instruction, c2});
-  insns.push_back((insn_desc_t){0x7b, 0x7f, &::illegal_instruction, c3, &::illegal_instruction, c3});
+  insns.push_back((insn_desc_t){true, 0x0b, 0x7f, &::illegal_instruction, c0, &::illegal_instruction, c0});
+  insns.push_back((insn_desc_t){true, 0x2b, 0x7f, &::illegal_instruction, c1, &::illegal_instruction, c1});
+  insns.push_back((insn_desc_t){true, 0x5b, 0x7f, &::illegal_instruction, c2, &::illegal_instruction, c2});
+  insns.push_back((insn_desc_t){true, 0x7b, 0x7f, &::illegal_instruction, c3, &::illegal_instruction, c3});
   return insns;
 }