[PATCH] RISC-V: fix FRM register display mask value

[Hugues de Lassus <hugues.delassus@sifive.com>]

The FRM register is 3-bit long, but the top-most bit was masked off for
display, resulting in incorrectly displayed values and format strings
when FRM >= 4.

Tested on riscv64-unknown-linux-gnu target, with FPU support.
---
 gdb/riscv-tdep.c                 | 2 +-
 gdb/testsuite/gdb.base/float.exp | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 69f2123dcdb..a3afab3b998 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -1185,7 +1185,7 @@ riscv_print_one_register_info (struct gdbarch *gdbarch,
 		      "dynamic rounding mode",
 		    };
 		  int frm = ((regnum == RISCV_CSR_FCSR_REGNUM)
-			     ? (d >> 5) : d) & 0x3;
+			     ? (d >> 5) : d) & 0x7;
 
 		  gdb_printf (file, "%sFRM:%i [%s]",
 			      (regnum == RISCV_CSR_FCSR_REGNUM
diff --git a/gdb/testsuite/gdb.base/float.exp b/gdb/testsuite/gdb.base/float.exp
index 62e8346928b..10c0692a976 100644
--- a/gdb/testsuite/gdb.base/float.exp
+++ b/gdb/testsuite/gdb.base/float.exp
@@ -112,14 +112,16 @@ if { [is_aarch64_target] } then {
     gdb_test "info float" "f0.*f1.*f31.*d0.*d30.*" "info float"
 } elseif [istarget "riscv*-*-*"] then {
     # RISC-V may or may not have an FPU
+    send_gdb "set \$frm = 7\n"
     gdb_test_multiple "info float" "info float" {
-	-re "ft0.*ft1.*ft11.*fflags.*frm.*fcsr.*$gdb_prompt $" {
+	-re "ft0.*ft1.*ft11.*fflags.*frm.*0x7.*FRM:7.*fcsr.*$gdb_prompt $" {
 	      pass "info float (with FPU)"
 	  }
 	-re "No floating.point info available for this processor.*$gdb_prompt $" {
 	      pass "info float (without FPU)"
 	}
     }
+    send_gdb "set \$frm = 0\n"
 } else {
     gdb_test "info float" "No floating.point info available for this processor." "info float (unknown target)"
 }
-- 
2.35.1