From aa0fde0a680d79995d4bc166c9fd1f3de3810960 Mon Sep 17 00:00:00 2001
From: Weiming Zhao <weimingz@codeaurora.org>
Date: Thu, 9 Nov 2017 17:32:57 +0000
Subject: [Builtins] Do not use tailcall for Thumb1

Summary:
The `b` instruction in Thumb1 has limited range, which may cause link-time errors if the jump target is far away.
This patch guards the tailcalls for non-Thumb1

Reviewers: peter.smith, compnerd, rengolin, eli.friedman

Reviewed By: rengolin

Subscribers: joerg, dalias, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D39700

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@317814 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/builtins/arm/aeabi_memcmp.S  |  6 ++++++
 lib/builtins/arm/aeabi_memcpy.S  |  6 ++++++
 lib/builtins/arm/aeabi_memmove.S |  6 ++++++
 lib/builtins/arm/aeabi_memset.S  | 12 ++++++++++++
 4 files changed, 30 insertions(+)

(limited to 'lib')

diff --git a/lib/builtins/arm/aeabi_memcmp.S b/lib/builtins/arm/aeabi_memcmp.S
index 33ea54848..e86d61137 100644
--- a/lib/builtins/arm/aeabi_memcmp.S
+++ b/lib/builtins/arm/aeabi_memcmp.S
@@ -14,7 +14,13 @@
         .syntax unified
         .p2align 2
 DEFINE_COMPILERRT_FUNCTION(__aeabi_memcmp)
+#ifdef USE_THUMB_1
+        push    {r7, lr}
+        bl      memcmp
+        pop     {r7, pc}
+#else
         b       memcmp
+#endif
 END_COMPILERRT_FUNCTION(__aeabi_memcmp)
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memcmp4, __aeabi_memcmp)
diff --git a/lib/builtins/arm/aeabi_memcpy.S b/lib/builtins/arm/aeabi_memcpy.S
index eabfa4904..e83c5fd4d 100644
--- a/lib/builtins/arm/aeabi_memcpy.S
+++ b/lib/builtins/arm/aeabi_memcpy.S
@@ -14,7 +14,13 @@
         .syntax unified
         .p2align 2
 DEFINE_COMPILERRT_FUNCTION(__aeabi_memcpy)
+#ifdef USE_THUMB_1
+        push    {r7, lr}
+        bl      memcpy
+        pop     {r7, pc}
+#else
         b       memcpy
+#endif
 END_COMPILERRT_FUNCTION(__aeabi_memcpy)
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memcpy4, __aeabi_memcpy)
diff --git a/lib/builtins/arm/aeabi_memmove.S b/lib/builtins/arm/aeabi_memmove.S
index 1bf08c0d5..ee28300e4 100644
--- a/lib/builtins/arm/aeabi_memmove.S
+++ b/lib/builtins/arm/aeabi_memmove.S
@@ -13,7 +13,13 @@
 
         .p2align 2
 DEFINE_COMPILERRT_FUNCTION(__aeabi_memmove)
+#ifdef USE_THUMB_1
+        push    {r7, lr}
+        bl      memmove
+        pop     {r7, pc}
+#else
         b       memmove
+#endif
 END_COMPILERRT_FUNCTION(__aeabi_memmove)
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memmove4, __aeabi_memmove)
diff --git a/lib/builtins/arm/aeabi_memset.S b/lib/builtins/arm/aeabi_memset.S
index b8022d9e6..0a678d762 100644
--- a/lib/builtins/arm/aeabi_memset.S
+++ b/lib/builtins/arm/aeabi_memset.S
@@ -18,7 +18,13 @@ DEFINE_COMPILERRT_FUNCTION(__aeabi_memset)
         mov     r3, r1
         mov     r1, r2
         mov     r2, r3
+#ifdef USE_THUMB_1
+        push    {r7, lr}
+        bl      memset
+        pop     {r7, pc}
+#else
         b       memset
+#endif
 END_COMPILERRT_FUNCTION(__aeabi_memset)
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memset4, __aeabi_memset)
@@ -28,7 +34,13 @@ DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memset8, __aeabi_memset)
 DEFINE_COMPILERRT_FUNCTION(__aeabi_memclr)
         mov     r2, r1
         movs    r1, #0
+#ifdef USE_THUMB_1
+        push    {r7, lr}
+        bl      memset
+        pop     {r7, pc}
+#else
         b       memset
+#endif
 END_COMPILERRT_FUNCTION(__aeabi_memclr)
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_memclr4, __aeabi_memclr)
-- 
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