add comment explaining use of insn._rd() in zeroing

diff --git a/riscv/insn_template_sv.cc b/riscv/insn_template_sv.cc
index 5da73bb65a7890257afde989fddd8085bec4f68a..475c8e542f7f7e78cb34f5ed7dfe6af46958480d 100644 (file)
--- a/riscv/insn_template_sv.cc
+++ b/riscv/insn_template_sv.cc
@@ -48,6 +48,7 @@ reg_t FN(processor_t* p, insn_t s_insn, reg_t pc)
 #if defined(USING_REG_RD) || defined(USING_REG_FRD)
       if (zeroing && ((dest_pred & (1<<voffs)) == 0))
       {
+          // insn._rd() would be predicated: have to use insn._rd() here
           WRITE_REG(insn._rd(), 0);
       }
 #endif