maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/lld/test/ELF/arm-bl-v6.s

65 lines
2.4 KiB
ArmAsm
Raw Normal View History

[ELF] Move `// REQUIRES:` line to the top llvm-svn: 335676
2018-06-27 06:20:04 +08:00
// REQUIRES: arm
[ELF] Add support for older Arm Architectures with smaller branch range The Thumb BL and BLX instructions on older Arm Architectures such as v5 and v6 have a constrained encoding J1 and J2 must equal 1, later Architectures relaxed this restriction allowing J1 and J2 to be used to calculate a larger immediate. This patch adds support for the old encoding, it is used when the build attributes for the input objects only contain older architectures. Differential Revision: https://reviews.llvm.org/D50076 llvm-svn: 340159
2018-08-20 17:19:30 +08:00
// RUN: llvm-mc -arm-add-build-attributes -filetype=obj -triple=armv6-none-linux-gnueabi %s -o %t
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// RUN: ld.lld %t -o %t2 2>&1
// RUN: llvm-objdump -d -triple=armv6-none-linux-gnueabi -start-address=69632 -stop-address=69640 %t2 | FileCheck -check-prefix=CHECK-ARM1 %s
// RUN: llvm-objdump -d -triple=thumbv6-none-linux-gnueabi %t2 -start-address=69640 -stop-address=69644 | FileCheck -check-prefix=CHECK-THUMB1 %s
// RUN: llvm-objdump -d -triple=armv6-none-linux-gnueabi -start-address=2166796 -stop-address=2166804 %t2 | FileCheck -check-prefix=CHECK-ARM2 %s
// RUN: llvm-objdump -d -triple=thumbv6-none-linux-gnueabi %t2 -start-address=6365184 -stop-address=6365186 | FileCheck -check-prefix=CHECK-THUMB2 %s
[ELF] Read ARM BuildAttributes section to determine supported features. lld assumes some ARM features that are not available in all Arm processors. In particular: - The blx instruction present for interworking. - The movt/movw instructions are used in Thunks. - The J1=1 J2=1 encoding of branch immediates to improve Thumb wide branch range are assumed to be present. This patch reads the ARM Attributes section to check for the architecture the object file was compiled with. If none of the objects have an architecture that supports either of these features a warning will be given. This is most likely to affect armv6 as used in the first Raspberry Pi. Differential Revision: https://reviews.llvm.org/D36823 llvm-svn: 319169
2017-11-28 21:51:48 +08:00
// On Arm v6 the range of a Thumb BL instruction is only 4 megabytes as the
// extended range encoding is not supported. The following example has a Thumb
// BL that is out of range on ARM v6 and requires a range extension thunk.
// As v6 does not support MOVT or MOVW instructions the Thunk must not
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// use these instructions either.
[ELF] Read ARM BuildAttributes section to determine supported features. lld assumes some ARM features that are not available in all Arm processors. In particular: - The blx instruction present for interworking. - The movt/movw instructions are used in Thunks. - The J1=1 J2=1 encoding of branch immediates to improve Thumb wide branch range are assumed to be present. This patch reads the ARM Attributes section to check for the architecture the object file was compiled with. If none of the objects have an architecture that supports either of these features a warning will be given. This is most likely to affect armv6 as used in the first Raspberry Pi. Differential Revision: https://reviews.llvm.org/D36823 llvm-svn: 319169
2017-11-28 21:51:48 +08:00
// ARM v6 supports blx so we shouldn't see the blx not supported warning.
// CHECK-NOT: warning: lld uses blx instruction, no object with architecture supporting feature detected.
.text
.syntax unified
.cpu arm1176jzf-s
.globl _start
.type _start,%function
.balign 0x1000
_start:
bl thumbfunc
bx lr
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// CHECK-ARM1: Disassembly of section .text:
// CHECK-ARM1-NEXT: _start:
// CHECK-ARM1-NEXT: 11000: 00 00 00 fa blx #0 <thumbfunc>
// CHECK-ARM1-NEXT: 11004: 1e ff 2f e1 bx lr
[ELF] Read ARM BuildAttributes section to determine supported features. lld assumes some ARM features that are not available in all Arm processors. In particular: - The blx instruction present for interworking. - The movt/movw instructions are used in Thunks. - The J1=1 J2=1 encoding of branch immediates to improve Thumb wide branch range are assumed to be present. This patch reads the ARM Attributes section to check for the architecture the object file was compiled with. If none of the objects have an architecture that supports either of these features a warning will be given. This is most likely to affect armv6 as used in the first Raspberry Pi. Differential Revision: https://reviews.llvm.org/D36823 llvm-svn: 319169
2017-11-28 21:51:48 +08:00
.thumb
.section .text.2, "ax", %progbits
.globl thumbfunc
.type thumbfunc,%function
thumbfunc:
bl farthumbfunc
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// CHECK-THUMB1: thumbfunc:
// CHECK-THUMB1-NEXT: 11008: 00 f2 00 e8 blx #2097152
// 6 Megabytes, enough to make farthumbfunc out of range of caller
// on a v6 Arm, but not on a v7 Arm.
[ELF] Read ARM BuildAttributes section to determine supported features. lld assumes some ARM features that are not available in all Arm processors. In particular: - The blx instruction present for interworking. - The movt/movw instructions are used in Thunks. - The J1=1 J2=1 encoding of branch immediates to improve Thumb wide branch range are assumed to be present. This patch reads the ARM Attributes section to check for the architecture the object file was compiled with. If none of the objects have an architecture that supports either of these features a warning will be given. This is most likely to affect armv6 as used in the first Raspberry Pi. Differential Revision: https://reviews.llvm.org/D36823 llvm-svn: 319169
2017-11-28 21:51:48 +08:00
.section .text.3, "ax", %progbits
.space 0x200000
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// CHECK-ARM2: __ARMv5ABSLongThunk_farthumbfunc:
// CHECK-ARM2-NEXT: 21100c: 04 f0 1f e5 ldr pc, [pc, #-4]
// CHECK-ARM2: $d:
// CHECK-ARM2-NEXT: 211010: 01 20 61 00 .word 0x00612001
[ELF] Read ARM BuildAttributes section to determine supported features. lld assumes some ARM features that are not available in all Arm processors. In particular: - The blx instruction present for interworking. - The movt/movw instructions are used in Thunks. - The J1=1 J2=1 encoding of branch immediates to improve Thumb wide branch range are assumed to be present. This patch reads the ARM Attributes section to check for the architecture the object file was compiled with. If none of the objects have an architecture that supports either of these features a warning will be given. This is most likely to affect armv6 as used in the first Raspberry Pi. Differential Revision: https://reviews.llvm.org/D36823 llvm-svn: 319169
2017-11-28 21:51:48 +08:00
.section .text.4, "ax", %progbits
.space 0x200000
.section .text.5, "ax", %progbits
.space 0x200000
.thumb
.section .text.6, "ax", %progbits
.balign 0x1000
.globl farthumbfunc
.type farthumbfunc,%function
farthumbfunc:
bx lr
[ELF] Add support for Armv5 and Armv6 compatible Thunks Older Arm architectures do not support the MOVT and MOVW instructions so we must use an alternative sequence of instructions to transfer control to the destination. Assuming at least Armv5 this patch adds support for Thunks that load or add to the program counter. Note that there are no Armv5 Thumb Thunks as there is no Thumb branch instruction in Armv5 that supports Thunks. These thunks will not work for Armv4t (arm7tdmi) as this architecture cannot change state from using the LDR or ADD instruction. Differential Revision: https://reviews.llvm.org/D50077 llvm-svn: 340160
2018-08-20 17:37:50 +08:00
// CHECK-THUMB2: farthumbfunc:
// CHECK-THUMB2-NEXT: 612000: 70 47 bx lr