[lld] r369246 - [ELF][ARM] Add a test that maxes out the thunk convergence limit
Peter Smith via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 19 02:46:53 PDT 2019
Author: psmith
Date: Mon Aug 19 02:46:52 2019
New Revision: 369246
URL: http://llvm.org/viewvc/llvm-project?rev=369246&view=rev
Log:
[ELF][ARM] Add a test that maxes out the thunk convergence limit
Add a test that takes the maximum amount of passes permitted to converge.
This will make sure that any symbol defined in a linker script gets the
correct value and that any other convergence limit involving symbol address
doesn't restrict Thunk convergence.
Differential Revision: https://reviews.llvm.org/D66346
Added:
lld/trunk/test/ELF/arm-thunk-many-passes.s
Added: lld/trunk/test/ELF/arm-thunk-many-passes.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/arm-thunk-many-passes.s?rev=369246&view=auto
==============================================================================
--- lld/trunk/test/ELF/arm-thunk-many-passes.s (added)
+++ lld/trunk/test/ELF/arm-thunk-many-passes.s Mon Aug 19 02:46:52 2019
@@ -0,0 +1,111 @@
+// REQUIRES: arm
+// RUN: llvm-mc -arm-add-build-attributes -filetype=obj -triple=armv7a-linux-gnueabihf %s -o %t
+// RUN: echo "SECTIONS { \
+// RUN: . = SIZEOF_HEADERS; \
+// RUN: .text 0x00011000 : { *(.text.*) } \
+// RUN: } \
+// RUN: sym = .;" > %t.script
+// RUN: ld.lld --script %t.script %t -o %t2
+// RUN: llvm-readobj --sections --symbols %t2 | FileCheck --check-prefix=CHECK-ELF %s
+// RUN: llvm-objdump --no-show-raw-insn --start-address=0x11000 --stop-address=0x1103c -d %t2 | FileCheck %s
+
+// An example of thunk generation that takes the maximum number of permitted
+// passes to converge. We start with a set of branches of which all but one are
+// in range. Any thunk added to extend the range of a branch is inserted in
+// between the branches and the targets which knocks some more branches out
+// of range. At the end of 9 passes of createThunks() every branch has a
+// range extension thunk, allowing the final pass to check that no more thunks
+// are required.
+//
+// As the size of the .text section changes 9 times, the symbol sym which
+// depends on the size of .text will be updated 9 times. This test checks that
+// any iteration limit to updating symbols does not limit thunk convergence.
+// up to its pass limit without
+//
+// CHECK-ELF: Name: .text
+// CHECK-ELF-NEXT: Type: SHT_PROGBITS
+// CHECK-ELF-NEXT: Flags [
+// CHECK-ELF-NEXT: SHF_ALLOC
+// CHECK-ELF-NEXT: SHF_EXECINSTR
+// CHECK-ELF-NEXT: ]
+// CHECK-ELF-NEXT: Address: 0x11000
+// CHECK-ELF-NEXT: Offset: 0x1000
+// CHECK-ELF-NEXT: Size: 16777292
+// CHECK-ELF: Name: sym
+// CHECK-ELF-NEXT: Value: 0x101104C
+
+// CHECK: 00011000 _start:
+// CHECK-NEXT: 11000: b.w #14680132 <__Thumbv7ABSLongThunk_f3>
+// CHECK-NEXT: 11004: b.w #14680128 <__Thumbv7ABSLongThunk_f3>
+// CHECK-NEXT: 11008: b.w #14680128 <__Thumbv7ABSLongThunk_f4>
+// CHECK-NEXT: 1100c: b.w #14680124 <__Thumbv7ABSLongThunk_f4>
+// CHECK-NEXT: 11010: b.w #14680124 <__Thumbv7ABSLongThunk_f5>
+// CHECK-NEXT: 11014: b.w #14680120 <__Thumbv7ABSLongThunk_f5>
+// CHECK-NEXT: 11018: b.w #14680120 <__Thumbv7ABSLongThunk_f6>
+// CHECK-NEXT: 1101c: b.w #14680116 <__Thumbv7ABSLongThunk_f6>
+// CHECK-NEXT: 11020: b.w #14680116 <__Thumbv7ABSLongThunk_f7>
+// CHECK-NEXT: 11024: b.w #14680112 <__Thumbv7ABSLongThunk_f7>
+// CHECK-NEXT: 11028: b.w #14680112 <__Thumbv7ABSLongThunk_f8>
+// CHECK-NEXT: 1102c: b.w #14680108 <__Thumbv7ABSLongThunk_f8>
+// CHECK-NEXT: 11030: b.w #14680108 <__Thumbv7ABSLongThunk_f9>
+// CHECK-NEXT: 11034: b.w #14680104 <__Thumbv7ABSLongThunk_f9>
+// CHECK-NEXT: 11038: b.w #14680104 <__Thumbv7ABSLongThunk_f10>
+
+
+ .thumb
+ .section .text.00, "ax", %progbits
+ .globl _start
+ .thumb_func
+_start: b.w f2
+ b.w f2
+ b.w f3
+ b.w f3
+ b.w f4
+ b.w f4
+ b.w f5
+ b.w f5
+ b.w f6
+ b.w f6
+ b.w f7
+ b.w f7
+ b.w f8
+ b.w f8
+ b.w f9
+ b.w f9
+ b.w f10
+ b.w f10
+
+ .section .text.01, "ax", %progbits
+ .space 14 * 1024 * 1024
+// Thunks are inserted here, initially only 1 branch is out of range and needs
+// a thunk. However the added thunk is 4-bytes in size which makes another
+// branch out of range, which adds another thunk ...
+ .section .text.02, "ax", %progbits
+ .space (2 * 1024 * 1024) - 68
+ .thumb_func
+f2: bx lr
+ nop
+ .thumb_func
+f3: bx lr
+ nop
+ .thumb_func
+f4: bx lr
+ nop
+ .thumb_func
+f5: bx lr
+ nop
+ .thumb_func
+f6: bx lr
+ nop
+ .thumb_func
+f7: bx lr
+ nop
+ .thumb_func
+f8: bx lr
+ nop
+ .thumb_func
+f9: bx lr
+ nop
+ .thumb_func
+f10: bx lr
+ nop
More information about the llvm-commits
mailing list