mirror of
https://github.com/c64scene-ar/llvm-6502.git
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b4b0b34181
Linkers normally read all the relocations upfront to compute the references between sections. Putting them together is a bit more cache friendly. I benchmarked linking a Release+Asserts clang with gold on a vm. I tried all 4 combinations of --gc-sections/no --gc-section hot and cold cache. I cleared the cache with echo 3 > /proc/sys/vm/drop_caches and warmed it up by running the link once before timing the subsequent ones. With cold cache and --gc-sections the time goes from 1.86130781665 +- 0.01713126697463843 seconds to 1.82370735105 +- 0.014127522318814516 seconds With cold cache and no --gc-sections the time goes from 1.6087245435500002 +- 0.012999066825178644 seconds to 1.5687122041500001 +- 0.013145850126026619 seconds With hot cache and no --gc-sections the time goes from 0.926200939 ( +- 0.33% ) seconds to 0.907200079 ( +- 0.31% ) seconds With hot cache and gc sections the time goes from 1.183038049 ( +- 0.34% ) seconds to 1.147355862 ( +- 0.39% ) seconds git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235165 91177308-0d34-0410-b5e6-96231b3b80d8
181 lines
6.0 KiB
ArmAsm
181 lines
6.0 KiB
ArmAsm
@ RUN: llvm-mc %s -triple=armv7-unknown-linux-gnueabi -filetype=obj -o - \
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@ RUN: | llvm-readobj -s -sd -sr -t > %t
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@ RUN: FileCheck %s < %t
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@ RUN: FileCheck --check-prefix=RELOC %s < %t
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@ Check the combination of .section, .fnstart, and .fnend directives.
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@ For the functions in .text section, the exception handling index (EXIDX)
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@ should be generated in .ARM.exidx, and the exception handling table (EXTAB)
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@ should be generated in .ARM.extab.
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@ For the functions in custom section specified by .section directives,
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@ the EXIDX should be generated in ".ARM.exidx[[SECTION_NAME]]", and the EXTAB
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@ should be generated in ".ARM.extab[[SECTION_NAME]]".
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.syntax unified
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@-------------------------------------------------------------------------------
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@ .TEST1 section
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@-------------------------------------------------------------------------------
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.section .TEST1
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.globl func1
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.align 2
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.type func1,%function
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.fnstart
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func1:
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bx lr
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.personality __gxx_personality_v0
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.handlerdata
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.fnend
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@-------------------------------------------------------------------------------
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@ TEST2 section (without the dot in the beginning)
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@-------------------------------------------------------------------------------
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.section TEST2
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.globl func2
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.align 2
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.type func2,%function
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.fnstart
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func2:
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bx lr
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.personality __gxx_personality_v0
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.handlerdata
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.fnend
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@-------------------------------------------------------------------------------
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@ Check the .TEST1 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Sections [
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@ CHECK: Section {
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@ CHECK: Index: 4
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@ CHECK: Name: .TEST1
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@ CHECK: SectionData (
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@ CHECK: 0000: 1EFF2FE1 |../.|
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@ CHECK: )
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@ CHECK: }
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@-------------------------------------------------------------------------------
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@ Check the .ARM.extab.TEST1 section, the EXTAB of .TEST1 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Section {
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@ CHECK: Name: .ARM.extab.TEST1
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@ CHECK: SectionData (
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@ CHECK: 0000: 00000000 B0B0B000 |........|
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@ CHECK: )
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@ CHECK: }
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@ RELOC: Section {
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@ RELOC: Name: .rel.ARM.extab.TEST1
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@ RELOC: Relocations [
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@ RELOC: 0x0 R_ARM_PREL31 __gxx_personality_v0 0x0
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@ RELOC: ]
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@ RELOC: }
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@-------------------------------------------------------------------------------
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@ Check the.ARM.exidx.TEST1 section, the EXIDX of .TEST1 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Section {
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@ CHECK: Name: .ARM.exidx.TEST1
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@-------------------------------------------------------------------------------
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@ This section should linked with .TEST1 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Link: 4
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@-------------------------------------------------------------------------------
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@ The first word should be relocated to the code address in .TEST1 section.
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@ The second word should be relocated to the EHTAB entry in .ARM.extab.TEST1
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@ section.
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@-------------------------------------------------------------------------------
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@ CHECK: SectionData (
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@ CHECK: 0000: 00000000 00000000 |........|
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@ CHECK: )
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@ CHECK: }
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@ RELOC: Section {
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@ RELOC: Name: .rel.ARM.exidx.TEST1
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@ RELOC: Relocations [
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@ RELOC: 0x0 R_ARM_PREL31 .TEST1 0x0
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@ RELOC: 0x4 R_ARM_PREL31 .ARM.extab.TEST1 0x0
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@ RELOC: ]
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@ RELOC: }
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@-------------------------------------------------------------------------------
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@ Check the TEST2 section (without the dot in the beginning)
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@-------------------------------------------------------------------------------
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@ CHECK: Section {
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@ CHECK: Index: 7
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@ CHECK: Name: TEST2
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@ CHECK: SectionData (
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@ CHECK: 0000: 1EFF2FE1 |../.|
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@ CHECK: )
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@ CHECK: }
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@-------------------------------------------------------------------------------
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@ Check the .ARM.extabTEST2 section, the EXTAB of TEST2 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Section {
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@ CHECK: Name: .ARM.extabTEST2
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@ CHECK: SectionData (
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@ CHECK: 0000: 00000000 B0B0B000 |........|
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@ CHECK: )
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@ CHECK: }
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@ RELOC: Section {
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@ RELOC: Name: .rel.ARM.extabTEST2
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@ RELOC: Relocations [
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@ RELOC: 0x0 R_ARM_PREL31 __gxx_personality_v0 0x0
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@ RELOC: ]
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@ RELOC: }
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@-------------------------------------------------------------------------------
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@ Check the .ARM.exidxTEST2 section, the EXIDX of TEST2 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Section {
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@ CHECK: Name: .ARM.exidxTEST2
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@-------------------------------------------------------------------------------
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@ This section should linked with TEST2 section.
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@-------------------------------------------------------------------------------
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@ CHECK: Link: 7
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@-------------------------------------------------------------------------------
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@ The first word should be relocated to the code address in TEST2 section.
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@ The second word should be relocated to the EHTAB entry in .ARM.extabTEST2
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@ section.
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@-------------------------------------------------------------------------------
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@ CHECK: SectionData (
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@ CHECK: 0000: 00000000 00000000 |........|
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@ CHECK: )
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@ CHECK: }
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@ RELOC: Section {
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@ RELOC: Name: .rel.ARM.exidxTEST2
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@ RELOC: Relocations [
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@ RELOC: 0x0 R_ARM_PREL31 TEST2 0x0
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@ RELOC: 0x4 R_ARM_PREL31 .ARM.extabTEST2 0x0
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@ RELOC: ]
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@ RELOC: }
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@-------------------------------------------------------------------------------
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@ Check the symbols and the sections they belong to
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@-------------------------------------------------------------------------------
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@ CHECK: Symbols [
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@ CHECK: Symbol {
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@ CHECK: Name: func1
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@ CHECK: Section: .TEST1 (0x4)
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@ CHECK: }
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@ CHECK: Symbol {
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@ CHECK: Name: func2
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@ CHECK: Section: TEST2 (0x7)
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@ CHECK: }
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@ CHECK: ]
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