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31dddc97ae
The AArch64 unconditional branch and branch and link instructions have a maximum range of 128 Mib. This is usually enough for most programs but there are cases when it isn't enough. This change adds support for range extension thunks to AArch64. For pc-relative thunks we follow the small code model and use ADRP, ADD, BR. This has a limit of 4 gigabytes. Differential Revision: https://reviews.llvm.org/D39744 llvm-svn: 319307
42 lines
1.5 KiB
ArmAsm
42 lines
1.5 KiB
ArmAsm
// RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu %s -o %t
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// RUN: echo "SECTIONS { \
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// RUN: .text_low 0x2000: { *(.text_low) } \
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// RUN: .text_high 0x8002000 : { *(.text_high) } \
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// RUN: } " > %t.script
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// RUN: ld.lld --script %t.script %t -o %t2 2>&1
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// RUN: llvm-objdump -d -triple=aarch64-linux-gnu %t2 | FileCheck %s
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// REQUIRES: aarch64
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// Check that we have the out of branch range calculation right. The immediate
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// field is signed so we have a slightly higher negative displacement.
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.section .text_low, "ax", %progbits
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.globl _start
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.type _start, %function
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_start:
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// Need thunk to high_target@plt
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bl high_target
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ret
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.section .text_high, "ax", %progbits
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.globl high_target
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.type high_target, %function
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high_target:
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// No Thunk needed as we are within signed immediate range
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bl _start
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ret
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// CHECK: Disassembly of section .text_low:
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// CHECK-NEXT: _start:
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// CHECK-NEXT: 2000: 02 00 00 94 bl #8
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// CHECK-NEXT: 2004: c0 03 5f d6 ret
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// CHECK: __AArch64AbsLongThunk_high_target:
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// CHECK-NEXT: 2008: 50 00 00 58 ldr x16, #8
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// CHECK-NEXT: 200c: 00 02 1f d6 br x16
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// CHECK: $d:
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// CHECK-NEXT: 2010: 00 20 00 08 .word 0x08002000
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// CHECK-NEXT: 2014: 00 00 00 00 .word 0x00000000
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// CHECK: Disassembly of section .text_high:
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// CHECK-NEXT: high_target:
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// CHECK-NEXT: 8002000: 00 00 00 96 bl #-134217728
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// CHECK-NEXT: 8002004: c0 03 5f d6 ret
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