diff --git a/gnu-system.am b/gnu-system.am
index 80d9438ad3..548f076c4c 100644
--- a/gnu-system.am
+++ b/gnu-system.am
@@ -220,6 +220,7 @@ dist_patch_DATA = \
gnu/packages/patches/flex-bison-tests.patch \
gnu/packages/patches/gawk-shell.patch \
gnu/packages/patches/gcc-cross-environment-variables.patch \
+ gnu/packages/patches/gdb-loongson-madd-fix.patch \
gnu/packages/patches/glib-tests-desktop.patch \
gnu/packages/patches/glib-tests-homedir.patch \
gnu/packages/patches/glib-tests-newnet.patch \
diff --git a/gnu/packages/gdb.scm b/gnu/packages/gdb.scm
index 09e00aaeb1..2033c628d7 100644
--- a/gnu/packages/gdb.scm
+++ b/gnu/packages/gdb.scm
@@ -17,6 +17,7 @@
;;; along with GNU Guix. If not, see .
(define-module (gnu packages gdb)
+ #:use-module (gnu packages)
#:use-module (gnu packages ncurses)
#:use-module (gnu packages readline)
#:use-module (gnu packages dejagnu)
@@ -39,7 +40,8 @@ (define-public gdb
version ".tar.bz2"))
(sha256
(base32
- "1r32s6vqgskw6pz9pmp41b8injd51c4bbxr6ifdpyid52j5a7pz3"))))
+ "1r32s6vqgskw6pz9pmp41b8injd51c4bbxr6ifdpyid52j5a7pz3"))
+ (patches (list (search-patch "gdb-loongson-madd-fix.patch")))))
(build-system gnu-build-system)
(arguments
'(#:phases (alist-cons-after
diff --git a/gnu/packages/patches/gdb-loongson-madd-fix.patch b/gnu/packages/patches/gdb-loongson-madd-fix.patch
new file mode 100644
index 0000000000..0d50dd2dd4
--- /dev/null
+++ b/gnu/packages/patches/gdb-loongson-madd-fix.patch
@@ -0,0 +1,44 @@
+Fix the Loongson 2F specific fused multiply-add instructions on paired singles to
+use the encoding recognized by the processor, as opposed to the mistaken english
+Loongson 2F documentation.
+
+Patch by Mark H Weaver .
+
+--- gdb/opcodes/mips-opc.c.orig 2013-02-09 05:24:18.000000000 -0500
++++ gdb/opcodes/mips-opc.c 2013-10-27 23:35:20.191997541 -0400
+@@ -956,7 +956,7 @@
+ {"madd.s", "D,S,T", 0x4600001c, 0xffe0003f, RD_S|RD_T|WR_D|FP_S, 0, EE },
+ {"madd.ps", "D,R,S,T", 0x4c000026, 0xfc00003f, RD_R|RD_S|RD_T|WR_D|FP_D, 0, I5_33 },
+ {"madd.ps", "D,S,T", 0x45600018, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2E },
+-{"madd.ps", "D,S,T", 0x71600018, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
++{"madd.ps", "D,S,T", 0x72c00018, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
+ {"madd", "s,t", 0x0000001c, 0xfc00ffff, RD_s|RD_t|WR_HILO, 0, L1 },
+ {"madd", "s,t", 0x70000000, 0xfc00ffff, RD_s|RD_t|MOD_HILO, 0, I32|N55 },
+ {"madd", "s,t", 0x70000000, 0xfc00ffff, RD_s|RD_t|WR_HILO|IS_M, 0, G1 },
+@@ -1084,7 +1084,7 @@
+ {"msub.s", "D,S,T", 0x4600001d, 0xffe0003f, RD_S|RD_T|WR_D|FP_S, 0, EE },
+ {"msub.ps", "D,R,S,T", 0x4c00002e, 0xfc00003f, RD_R|RD_S|RD_T|WR_D|FP_D, 0, I5_33 },
+ {"msub.ps", "D,S,T", 0x45600019, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2E },
+-{"msub.ps", "D,S,T", 0x71600019, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
++{"msub.ps", "D,S,T", 0x72c00019, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
+ {"msub", "s,t", 0x0000001e, 0xfc00ffff, RD_s|RD_t|WR_HILO, 0, L1 },
+ {"msub", "s,t", 0x70000004, 0xfc00ffff, RD_s|RD_t|MOD_HILO, 0, I32|N55 },
+ {"msub", "7,s,t", 0x70000004, 0xfc00e7ff, MOD_a|RD_s|RD_t, 0, D32 },
+@@ -1218,7 +1218,7 @@
+ {"nmadd.s", "D,S,T", 0x7200001a, 0xffe0003f, RD_S|RD_T|WR_D|FP_S, 0, IL2F },
+ {"nmadd.ps","D,R,S,T", 0x4c000036, 0xfc00003f, RD_R|RD_S|RD_T|WR_D|FP_D, 0, I5_33 },
+ {"nmadd.ps", "D,S,T", 0x4560001a, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2E },
+-{"nmadd.ps", "D,S,T", 0x7160001a, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
++{"nmadd.ps", "D,S,T", 0x72c0001a, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
+ {"nmsub.d", "D,R,S,T", 0x4c000039, 0xfc00003f, RD_R|RD_S|RD_T|WR_D|FP_D, 0, I4_33 },
+ {"nmsub.d", "D,S,T", 0x4620001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2E },
+ {"nmsub.d", "D,S,T", 0x7220001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
+@@ -1227,7 +1227,7 @@
+ {"nmsub.s", "D,S,T", 0x7200001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_S, 0, IL2F },
+ {"nmsub.ps","D,R,S,T", 0x4c00003e, 0xfc00003f, RD_R|RD_S|RD_T|WR_D|FP_D, 0, I5_33 },
+ {"nmsub.ps", "D,S,T", 0x4560001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2E },
+-{"nmsub.ps", "D,S,T", 0x7160001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
++{"nmsub.ps", "D,S,T", 0x72c0001b, 0xffe0003f, RD_S|RD_T|WR_D|FP_D, 0, IL2F },
+ /* nop is at the start of the table. */
+ {"nor", "d,v,t", 0x00000027, 0xfc0007ff, WR_d|RD_s|RD_t, 0, I1 },
+ {"nor", "t,r,I", 0, (int) M_NOR_I, INSN_MACRO, 0, I1 },