[ELF] Introduce range extension thunks for ARM
This change adds initial support for range extension thunks. All thunks must
be created within the first pass so some corner cases are not supported. A
follow up patch will add support for multiple passes.
With this change the existing tests arm-branch-error.s and
arm-thumb-branch-error.s now no longer fail with an out of range branch.
These have been renamed and tests added for the range extension thunk.
Differential Revision: https://reviews.llvm.org/D34691
llvm-svn: 316752
diff --git a/lld/test/ELF/arm-thumb-mix-range-thunk-os.s b/lld/test/ELF/arm-thumb-mix-range-thunk-os.s
new file mode 100644
index 0000000..beff4148
--- /dev/null
+++ b/lld/test/ELF/arm-thumb-mix-range-thunk-os.s
@@ -0,0 +1,195 @@
+// REQUIRES: arm
+// RUN: llvm-mc -filetype=obj -triple=armv7a-none-linux-gnueabi %s -o %t
+// RUN: ld.lld %t -o %t2 2>&1
+// The output file is large, most of it zeroes. We dissassemble only the
+// parts we need to speed up the test and avoid a large output file
+// RUN: llvm-objdump -d %t2 -start-address=1048576 -stop-address=1048604 -triple=armv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK1 %s
+// RUN: llvm-objdump -d %t2 -start-address=2097152 -stop-address=2097162 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK2 %s
+// RUN: llvm-objdump -d %t2 -start-address=16777220 -stop-address=16777232 -triple=armv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK3 %s
+// RUN: llvm-objdump -d %t2 -start-address=16777232 -stop-address=16777242 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK4 %s
+// RUN: llvm-objdump -d %t2 -start-address=32505860 -stop-address=32505870 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK5 %s
+// RUN: llvm-objdump -d %t2 -start-address=35651584 -stop-address=35651590 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK6 %s
+// RUN: llvm-objdump -d %t2 -start-address=36700160 -stop-address=36700168 -triple=armv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK7 %s
+// RUN: llvm-objdump -d %t2 -start-address=48234500 -stop-address=48234512 -triple=armv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK8 %s
+// RUN: llvm-objdump -d %t2 -start-address=63963140 -stop-address=63963160 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK9 %s
+// RUN: llvm-objdump -d %t2 -start-address=68157440 -stop-address=68157452 -triple=armv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK10 %s
+// RUN: llvm-objdump -d %t2 -start-address=69206016 -stop-address=69206024 -triple=thumbv7a-linux-gnueabihf | FileCheck -check-prefix=CHECK11 %s
+
+// Test the Range extension Thunks for ARM and Thumb when all the code is in a
+// single OutputSection. The ARM branches and branch and link instructions
+// have a range of 32Mb, the Thumb unconditional branch and
+// branch and link instructions have . We create a series of Functions a
+// megabyte apart. We expect range extension thunks to be created when a
+// branch is out of range. Thunks will be reused whenever they are in range
+ .syntax unified
+
+// Define a function aligned on a megabyte boundary
+ .macro ARMFUNCTION suff
+ .section .text.\suff\(), "ax", %progbits
+ .arm
+ .balign 0x100000
+ .globl afunc\suff\()
+ .type afunc\suff\(), %function
+afunc\suff\():
+ bx lr
+ .endm
+
+// Define a function aligned on a megabyte boundary
+ .macro THUMBFUNCTION suff
+ .section .text.\suff\(), "ax", %progbits
+ .thumb
+ .balign 0x100000
+ .globl tfunc\suff\()
+ .type tfunc\suff\(), %function
+tfunc\suff\():
+ bx lr
+ .endm
+
+ .section .text, "ax", %progbits
+ .thumb
+ .globl _start
+_start:
+
+ ARMFUNCTION 00
+// Expect ARM bl to be in range (can use blx to change state)
+ bl tfunc31
+// ARM b and beq are in range but need Thunk to change state to Thumb
+ b tfunc31
+ beq tfunc31
+// afunc32 is out of range of ARM branch and branch and link
+ bl afunc32
+ b afunc32
+ bne afunc32
+// CHECK1: afunc00:
+// CHECK1-NEXT: 100000: 1e ff 2f e1 bx lr
+// CHECK1-NEXT: 100004: fd ff 7b fa blx #32505844
+// CHECK1-NEXT: 100008: fd ff 3b ea b #15728628
+// CHECK1-NEXT: 10000c: fc ff 3b 0a beq #15728624
+// CHECK1-NEXT: 100010: fa ff 7f eb bl #33554408
+// CHECK1-NEXT: 100014: f9 ff 7f ea b #33554404
+// CHECK1-NEXT: 100018: f8 ff 7f 1a bne #33554400
+ THUMBFUNCTION 01
+// Expect Thumb bl to be in range (can use blx to change state)
+ bl afunc14
+// In range but need thunk to change state to Thumb
+ b.w afunc14
+// CHECK2: tfunc01:
+// CHECK2-NEXT: 200000: 70 47 bx lr
+// CHECK2-NEXT: 200002: ff f0 fe c7 blx #13631484
+// CHECK2-NEXT: 200006: 00 f2 03 90 b.w #14680070 <__Thumbv7ABSLongThunk_afunc14>
+
+ ARMFUNCTION 02
+ THUMBFUNCTION 03
+ ARMFUNCTION 04
+ THUMBFUNCTION 05
+ ARMFUNCTION 06
+ THUMBFUNCTION 07
+ ARMFUNCTION 08
+ THUMBFUNCTION 09
+ ARMFUNCTION 10
+ THUMBFUNCTION 11
+ ARMFUNCTION 12
+ THUMBFUNCTION 13
+ ARMFUNCTION 14
+// CHECK3: __ARMv7ABSLongThunk_tfunc31:
+// CHECK3-NEXT: 1000004: 01 c0 00 e3 movw r12, #1
+// CHECK3-NEXT: 1000008: 00 c2 40 e3 movt r12, #512
+// CHECK3-NEXT: 100000c: 1c ff 2f e1 bx r12
+// CHECK4: __Thumbv7ABSLongThunk_afunc14:
+// CHECK4-NEXT: 1000010: 40 f2 00 0c movw r12, #0
+// CHECK4-NEXT: 1000014: c0 f2 f0 0c movt r12, #240
+// CHECK4-NEXT: 1000018: 60 47 bx r12
+ THUMBFUNCTION 15
+ ARMFUNCTION 16
+ THUMBFUNCTION 17
+ ARMFUNCTION 18
+ THUMBFUNCTION 19
+ ARMFUNCTION 20
+ THUMBFUNCTION 21
+ ARMFUNCTION 22
+ THUMBFUNCTION 23
+ ARMFUNCTION 24
+ THUMBFUNCTION 25
+ ARMFUNCTION 26
+ THUMBFUNCTION 27
+ ARMFUNCTION 28
+ THUMBFUNCTION 29
+ ARMFUNCTION 30
+// Expect precreated Thunk Section here
+// CHECK5: __Thumbv7ABSLongThunk_afunc00:
+// CHECK5-NEXT: 1f00004: 40 f2 00 0c movw r12, #0
+// CHECK5-NEXT: 1f00008: c0 f2 10 0c movt r12, #16
+// CHECK5-NEXT: 1f0000c: 60 47 bx r12
+ THUMBFUNCTION 31
+ ARMFUNCTION 32
+ THUMBFUNCTION 33
+// Out of range, can only reach closest Thunk Section
+ bl afunc00
+// CHECK6: tfunc33:
+// CHECK6-NEXT: 2200000: 70 47 bx lr
+// CHECK6-NEXT: 2200002: ff f4 ff ff bl #-3145730
+ ARMFUNCTION 34
+// Out of range, can reach earlier Thunk Section
+// CHECK7: afunc34:
+// CHECK7-NEXT: 2300000: 1e ff 2f e1 bx lr
+// CHECK7-NEXT: 2300004: fe ff ef fa blx #-4194312 <__Thumbv7ABSLongThunk_afunc00
+ bl afunc00
+ THUMBFUNCTION 35
+ ARMFUNCTION 36
+ THUMBFUNCTION 37
+ ARMFUNCTION 38
+ THUMBFUNCTION 39
+ ARMFUNCTION 40
+ THUMBFUNCTION 41
+ ARMFUNCTION 42
+ THUMBFUNCTION 43
+ ARMFUNCTION 44
+ THUMBFUNCTION 45
+// Expect precreated Thunk Section here
+// CHECK8: __ARMv7ABSLongThunk_tfunc35:
+// CHECK8-NEXT: 2e00004: 01 c0 00 e3 movw r12, #1
+// CHECK8-NEXT: 2e00008: 40 c2 40 e3 movt r12, #576
+// CHECK8-NEXT: 2e0000c: 1c ff 2f e1 bx r12
+ ARMFUNCTION 46
+ THUMBFUNCTION 47
+ ARMFUNCTION 48
+ THUMBFUNCTION 49
+ ARMFUNCTION 50
+ THUMBFUNCTION 51
+ ARMFUNCTION 52
+ THUMBFUNCTION 53
+ ARMFUNCTION 54
+ THUMBFUNCTION 55
+ ARMFUNCTION 56
+ THUMBFUNCTION 57
+ ARMFUNCTION 58
+ THUMBFUNCTION 59
+ ARMFUNCTION 60
+// Expect precreated Thunk Section here
+// CHECK9: __Thumbv7ABSLongThunk_afunc34:
+// CHECK9-NEXT: 3d00004: 40 f2 00 0c movw r12, #0
+// CHECK9-NEXT: 3d00008: c0 f2 30 2c movt r12, #560
+// CHECK9-NEXT: 3d0000c: 60 47 bx r12
+// CHECK9: __Thumbv7ABSLongThunk_tfunc35:
+// CHECK9-NEXT: 3d0000e: 40 f2 01 0c movw r12, #1
+// CHECK9-NEXT: 3d00012: c0 f2 40 2c movt r12, #576
+// CHECK9-NEXT: 3d00016: 60 47 bx r12
+ THUMBFUNCTION 61
+ ARMFUNCTION 62
+ THUMBFUNCTION 63
+ ARMFUNCTION 64
+// afunc34 is in range, as is tfunc35 but a branch needs a state change Thunk
+ bl afunc34
+ b tfunc35
+// CHECK10: afunc64:
+// CHECK10-NEXT: 4100000: 1e ff 2f e1 bx lr
+// CHECK10-NEXT: 4100004: fd ff 87 eb bl #-31457292 <afunc34>
+// CHECK10-NEXT: 4100008: fd ff b3 ea b #-19922956 <__ARMv7ABSLongThunk_tfunc35>
+ THUMBFUNCTION 65
+// afunc34 and tfunc35 are both out of range
+ bl afunc34
+ bl tfunc35
+// CHECK11: tfunc65:
+// CHECK11: 4200000: 70 47 bx lr
+// CHECK11-NEXT: 4200002: ff f6 ff f7 bl #-5242882
+// CHECK11-NEXT: 4200006: 00 f7 02 f0 bl #-5242876
