From 2dfc5fd1eacb8b642296eb954769d72b83d863d7 Mon Sep 17 00:00:00 2001
From: Davide Italiano <davide@freebsd.org>
Date: Fri, 15 Jan 2016 01:49:51 +0000
Subject: [PATCH] [ELF/AArch64] Add support for R_AARCH64_LDST16_ABS_LO12_NC
 relocation.

Found while trying to self-host the toolchain that libLTO needs it.

llvm-svn: 257854
---
 lld/ELF/Target.cpp            |  4 ++++
 lld/test/ELF/aarch64-relocs.s | 14 ++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index 3597566fe6e6..5d93b8d90606 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -1271,6 +1271,7 @@ bool AArch64TargetInfo::needsCopyRel(uint32_t Type, const SymbolBody &S) const {
   case R_AARCH64_ADR_PREL_LO21:
   case R_AARCH64_ADR_PREL_PG_HI21:
   case R_AARCH64_LDST8_ABS_LO12_NC:
+  case R_AARCH64_LDST16_ABS_LO12_NC:
   case R_AARCH64_LDST32_ABS_LO12_NC:
   case R_AARCH64_LDST64_ABS_LO12_NC:
   case R_AARCH64_LDST128_ABS_LO12_NC:
@@ -1384,6 +1385,9 @@ void AArch64TargetInfo::relocateOne(uint8_t *Loc, uint8_t *BufEnd,
   case R_AARCH64_LDST128_ABS_LO12_NC:
     or32le(Loc, (SA & 0x0FF8) << 6);
     break;
+  case R_AARCH64_LDST16_ABS_LO12_NC:
+    or32le(Loc, (SA & 0x0FFC) << 9);
+    break;
   case R_AARCH64_LDST8_ABS_LO12_NC:
     or32le(Loc, (SA & 0xFFF) << 10);
     break;
diff --git a/lld/test/ELF/aarch64-relocs.s b/lld/test/ELF/aarch64-relocs.s
index bc00679e7e86..90541329587a 100644
--- a/lld/test/ELF/aarch64-relocs.s
+++ b/lld/test/ELF/aarch64-relocs.s
@@ -136,3 +136,17 @@ foo128:
 # CHECK:   1104c:       74 16 c0 3d     ldr     q20, [x19, #80]
 #foo128:
 #   11050:       66 6f 6f 00     .word
+
+.section .R_AARCH64_LDST16_ABS_LO12_NC,"ax",@progbits
+ldst16:
+  ldr h17, [x19, :lo12:foo16]
+foo16:
+  .asciz "foo"
+  .size mystr, 3
+
+# S = 0x11054, A = 0x4
+# R = ((S + A) & 0x0FFC) << 9 = 0xb000
+# 0xb000 | 0x7d400271 = 0x7d40b271
+# CHECK: Disassembly of section .R_AARCH64_LDST16_ABS_LO12_NC:
+# CHECK-NEXT: ldst16:
+# CHECK-NEXT:   11054:       71 b2 40 7d     ldr     h17, [x19, #88]