ARM: don't diagnose cbz/cbnz to Thumb functions.

A branch-distance to a Thumb function shouldn't be forced to be odd for
CBZ/CBNZ instructions because (assuming it's within range), it's going to be a
valid, even offset.

llvm-svn: 279665

Author: TNorthover

llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

@@ -710,7 +710,8 @@ void ARMAsmBackend::processFixupValue(const MCAssembler &Asm,
       (unsigned)Fixup.getKind() != ARM::fixup_arm_adr_pcrel_12 &&
       (unsigned)Fixup.getKind() != ARM::fixup_thumb_adr_pcrel_10 &&
       (unsigned)Fixup.getKind() != ARM::fixup_t2_adr_pcrel_12 &&
-      (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp) {
+      (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp &&
+      (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cb) {
     if (Sym) {
       if (Asm.isThumbFunc(Sym))
         Value |= 1;

llvm/test/MC/ARM/thumb-cb-negative-offsets.s renamed to llvm/test/MC/ARM/thumb-cb-offsets.s

@@ -24,6 +24,13 @@ label1:
 label2:
   nop
 
+@ CHECK: out of range pc-relative fixup value
+  cbz r0, label4
+  .space 33
+label4:
+  nop
+
+  .align 2
 @ CHECK-NOT: label3
   cbnz r0, label3
   .space 128

llvm/test/MC/ARM/thumb-cb-thumbfunc.s

@@ -0,0 +1,8 @@
+@ RUN: llvm-mc -triple thumbv7-apple-macho -filetype=obj -o %t %s
+@ RUN: llvm-objdump -d -triple thumbv7 %t | FileCheck %s
+
+@ CHECK: cbnz r0, #0
+  .thumb_func label4
+  cbnz r0, label4
+  .space 2
+label4: