[ARM] Create relocations for unconditional branches.

Summary:
Relocations are required for unconditional branches to function symbols with
different execution mode. Without this patch, incorrect branches are
generated for tail calls between functions with different execution
mode.


Reviewers: peter.smith, rafael, echristo, kristof.beyls

Reviewed By: peter.smith

Subscribers: aemerson, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33898

llvm-svn: 304882

1 files changed, 25 insertions, 0 deletions

diff --git a/llvm/test/MC/ARM/arm-thumb-tail-call.ll b/llvm/test/MC/ARM/arm-thumb-tail-call.ll
new file mode 100644
index 00000000000..c166719505d
--- /dev/null
+++ b/llvm/test/MC/ARM/arm-thumb-tail-call.ll
@@ -0,0 +1,25 @@
+; RUN: llc -O0 < %s -mtriple armv7-linux-gnueabi -o - \
+; RUN:   | llvm-mc -triple armv7-linux-gnueabi -filetype=obj -o - \
+; RUN:    | llvm-readobj -r | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv7--linux-gnueabihf"
+
+define internal i32 @arm_fn() #1 {
+  %1 = tail call i32 @thumb_fn()
+  ret i32 %1
+}
+
+define internal i32 @thumb_fn() #2 {
+  %1 = tail call i32 @arm_fn()
+  ret i32 %1
+}
+
+attributes #1 = { "target-features"="-thumb-mode" }
+attributes #2 = { "target-features"="+thumb-mode" }
+
+; CHECK: Relocations [
+; CHECK-NEXT: Section (3) .rel.text {
+; CHECK-NEXT: 0x0 R_ARM_JUMP24 thumb_fn 0x0
+; CHECK-NEXT: 0x4 R_ARM_THM_JUMP24 arm_fn 0x0
+; CHECK-NEXT: }