[binutils-gdb] gdb/riscv: correct dwarf to gdb register number mapping

[Andrew Burgess <aburgess@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c8ea5e409b02cf7fa848e44af74b2e8246ad03f1

commit c8ea5e409b02cf7fa848e44af74b2e8246ad03f1
Author: Xiao Zeng <zengxiao@eswincomputing.com>
Date:   Tue Dec 6 14:59:43 2022 +0800

    gdb/riscv: correct dwarf to gdb register number mapping
    
    According to the riscv psabi, the mapping relationship between the
    DWARF registers and the machine registers is as follows:
    
      DWARF Number | Register Name | Description
      0 - 31       | x0 - x31      | Integer Registers
      32 - 63      | f0 - f31      | Floating-point Registers
    
    This is not modelled quite right in riscv_dwarf_reg_to_regnum, the
    DWARF register numbers 31 and 63 are not handled correctly due to a
    use of '<' instead of '<='.  This commit fixes this issue.

Diff:
---
 gdb/riscv-tdep.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 0a050b272ff..a298623b449 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -3623,10 +3623,10 @@ riscv_add_reggroups (struct gdbarch *gdbarch)
 static int
 riscv_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
 {
-  if (reg < RISCV_DWARF_REGNUM_X31)
+  if (reg <= RISCV_DWARF_REGNUM_X31)
     return RISCV_ZERO_REGNUM + (reg - RISCV_DWARF_REGNUM_X0);
 
-  else if (reg < RISCV_DWARF_REGNUM_F31)
+  else if (reg <= RISCV_DWARF_REGNUM_F31)
     return RISCV_FIRST_FP_REGNUM + (reg - RISCV_DWARF_REGNUM_F0);
 
   else if (reg >= RISCV_DWARF_FIRST_CSR && reg <= RISCV_DWARF_LAST_CSR)