Index: lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
===================================================================
--- lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -729,6 +729,10 @@
     // linker can handle it. GNU AS produces an error in this case.
     if (Sym->isExternal() || Value >= 0x400004)
       IsResolved = false;
+    // When an ARM function is called from a Thumb function, produce a
+    // relocation so the linker will use the correct branch instruction.
+    if (!Asm.isThumbFunc(Sym))
+      IsResolved = false;
   }
   // We must always generate a relocation for BL/BLX instructions if we have
   // a symbol to reference, as the linker relies on knowing the destination
Index: test/MC/ARM/big-endian-thumb-fixup.s
===================================================================
--- test/MC/ARM/big-endian-thumb-fixup.s
+++ test/MC/ARM/big-endian-thumb-fixup.s
@@ -4,6 +4,7 @@
 	.text
 	.align	2
 	.code 16
+	.thumb_func
 
 @ARM::fixup_arm_thumb_bl
 .section s_thumb_bl,"ax",%progbits
Index: test/MC/ARM/mixed-arm-thumb-bl-fixup.s
===================================================================
--- /dev/null
+++ test/MC/ARM/mixed-arm-thumb-bl-fixup.s
@@ -0,0 +1,47 @@
+@ RUN: llvm-mc < %s -triple armv7-linux-gnueabi -filetype=obj -o - \
+@ RUN:   | llvm-readobj -r | FileCheck %s
+
+	.code	16
+	.thumb_func
+thumb_caller:
+	bl	internal_arm_fn
+	bl	global_arm_fn
+	bl	internal_thumb_fn
+	bl	global_thumb_fn
+
+	.globl	arm_caller
+	.code	32
+arm_caller:
+	bl	internal_arm_fn
+	bl	global_arm_fn
+	bl	internal_thumb_fn
+	bl	global_thumb_fn
+
+	.code	32
+internal_arm_fn:
+	bx	lr
+
+	.globl	global_arm_fn
+	.type	global_arm_fn,%function
+	.code	32
+global_arm_fn:
+	bx	lr
+
+	.code	16
+	.thumb_func
+internal_thumb_fn:
+	bx	lr
+
+	.globl	global_thumb_fn
+	.code	16
+	.thumb_func
+global_thumb_fn:
+	bx	lr
+
+@ CHECK: 0x0 R_ARM_THM_CALL internal_arm_fn 0x0
+@ CHECK: 0x4 R_ARM_THM_CALL global_arm_fn 0x0
+@ CHECK: 0xC R_ARM_THM_CALL global_thumb_fn 0x0
+@ CHECK: 0x10 R_ARM_CALL internal_arm_fn 0x0
+@ CHECK: 0x14 R_ARM_CALL global_arm_fn 0x0
+@ CHECK: 0x18 R_ARM_CALL internal_thumb_fn 0x0
+@ CHECK: 0x1C R_ARM_CALL global_thumb_fn 0x0
Index: test/MC/ARM/thumb-far-jump.s
===================================================================
--- test/MC/ARM/thumb-far-jump.s
+++ test/MC/ARM/thumb-far-jump.s
@@ -22,5 +22,5 @@
 main2:
 	bx	lr
 
-@ CHECK-NOT: 0x0 R_ARM_THM_CALL end 0x0
+@ CHECK: 0x0 R_ARM_THM_CALL end 0x0
 @ CHECK: 0x2004 R_ARM_THM_CALL main2 0x0