[arm] Add big-endian version of pcrel fixups for adr instructions

Summary:
In 2e24219, a number of ARM pcrel fixups were resolved at assembly
time, to solve PR44929. This only covered little-endian ARM however, so
add similar fixups for big-endian ARM. Also extend the test case to
cover big-endian ARM.

Reviewers: hans, psmith, MaskRay

Reviewed By: psmith, MaskRay

Subscribers: kristof.beyls, hiraditya, danielkiss, emaste, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79774

(cherry picked from commit fc37352)

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

@@ -116,26 +116,22 @@ const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
       // ARMFixupKinds.h.
       //
       // Name                      Offset (bits) Size (bits)     Flags
-      {"fixup_arm_ldst_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+      {"fixup_arm_ldst_pcrel_12", 0, 32, IsPCRelConstant},
       {"fixup_t2_ldst_pcrel_12", 0, 32,
-       MCFixupKindInfo::FKF_IsPCRel |
-           MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
-      {"fixup_arm_pcrel_10_unscaled", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
-      {"fixup_arm_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+       IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+      {"fixup_arm_pcrel_10_unscaled", 0, 32, IsPCRelConstant},
+      {"fixup_arm_pcrel_10", 0, 32, IsPCRelConstant},
       {"fixup_t2_pcrel_10", 0, 32,
        MCFixupKindInfo::FKF_IsPCRel |
            MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
       {"fixup_arm_pcrel_9", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
       {"fixup_t2_pcrel_9", 0, 32,
-       MCFixupKindInfo::FKF_IsPCRel |
-           MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+       IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
       {"fixup_thumb_adr_pcrel_10", 8, 8,
-       MCFixupKindInfo::FKF_IsPCRel |
-           MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
-      {"fixup_arm_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+       IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+      {"fixup_arm_adr_pcrel_12", 0, 32, IsPCRelConstant},
       {"fixup_t2_adr_pcrel_12", 0, 32,
-       MCFixupKindInfo::FKF_IsPCRel |
-           MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+       IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
       {"fixup_arm_condbranch", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
       {"fixup_arm_uncondbranch", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
       {"fixup_t2_condbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},

llvm/test/MC/ARM/pcrel-global.s

@@ -1,5 +1,7 @@
 @ RUN: llvm-mc -filetype=obj -triple=armv7 %s -o %t
 @ RUN: llvm-readelf -r %t | FileCheck %s
+@ RUN: llvm-mc -filetype=obj -triple=armebv7 %s -o %t
+@ RUN: llvm-readelf -r %t | FileCheck %s
 
 @ CHECK: There are no relocations in this file.
 .syntax unified