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[mips] Correct jal expansion for local symbols in .local directives.
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This patch corrects the behaviour of code such as:

   .local foo
   jal foo
foo:
to use the correct jal expansion when writing ELF files.

Patch by: Daniel Sanders

Reviewers: zoran.jovanovic, seanbruno, vkalintiris

Differential Revision: https://reviews.llvm.org/D24722

llvm-svn: 287918
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Simon Dardis committed Nov 25, 2016
1 parent 0479957 commit c08af6d
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Showing 2 changed files with 129 additions and 29 deletions.
3 changes: 2 additions & 1 deletion llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
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Expand Up @@ -1806,7 +1806,8 @@ bool MipsAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
// FIXME: Add support for label+offset operands (currently causes an error).
// FIXME: Add support for forward-declared local symbols.
// FIXME: Add expansion for when the LargeGOT option is enabled.
if (JalSym->isInSection() || JalSym->isTemporary()) {
if (JalSym->isInSection() || JalSym->isTemporary() ||
(JalSym->isELF() && cast<MCSymbolELF>(JalSym)->getBinding() == ELF::STB_LOCAL)) {
if (isABI_O32()) {
// If it's a local symbol and the O32 ABI is being used, we expand to:
// lw $25, 0($gp)
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155 changes: 127 additions & 28 deletions llvm/test/MC/Mips/expansion-jal-sym-pic.s
View file
Expand Up @@ -16,6 +16,18 @@
# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64 -target-abi n64 -mattr=micromips -show-encoding |\
# RUN: FileCheck %s -check-prefixes=ALL,MICROMIPS,N64-MICROMIPS

# Repeat the tests but using ELF output. An initial version of this patch did
# this as the output different depending on whether it went through
# MCAsmStreamer or MCELFStreamer. This ensures that the assembly expansion and
# direct objection emission match.

# RUN: llvm-mc %s -arch=mips -mcpu=mips32 -filetype=obj | \
# RUN: llvm-objdump -d -r - | FileCheck %s -check-prefixes=ELF-O32
# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64 -target-abi n32 -filetype=obj | \
# RUN: llvm-objdump -d -r - | FileCheck %s -check-prefixes=ELF-N32
# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64 -target-abi n64 -filetype=obj | \
# RUN: llvm-objdump -d -r - | FileCheck %s -check-prefixes=ELF-N64

.weak weak_label

.text
Expand All @@ -29,38 +41,28 @@ local_label:
jal local_label
nop

jal weak_label
nop

jal global_label
nop

jal .text
nop

# local labels ($tmp symbols)
jal 1f
nop

.end local_label

1:
nop
add $8, $8, $8
nop

# Expanding "jal local_label":
# O32: lw $25, %got(local_label)($gp) # encoding: [0x8f,0x99,A,A]
# O32: # fixup A - offset: 0, value: %got(local_label), kind: fixup_Mips_GOT
# O32: addiu $25, $25, %lo(local_label) # encoding: [0x27,0x39,A,A]
# O32: # fixup A - offset: 0, value: %lo(local_label), kind: fixup_Mips_LO16
# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_GOT16 .text
# ELF-O32-NEXT: 27 39 00 00 addiu $25, $25, 0
# ELF-O32-NEXT: R_MIPS_LO16 .text

# N32: lw $25, %got_disp(local_label)($gp) # encoding: [0x8f,0x99,A,A]
# N32: # fixup A - offset: 0, value: %got_disp(local_label), kind: fixup_Mips_GOT_DISP

# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE local_label

# N64: ld $25, %got_disp(local_label)($gp) # encoding: [0xdf,0x99,A,A]
# N64: # fixup A - offset: 0, value: %got_disp(local_label), kind: fixup_Mips_GOT_DISP

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE local_label

# O32-MICROMIPS: lw $25, %got(local_label)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS: # fixup A - offset: 0, value: %got(local_label), kind: fixup_MICROMIPS_GOT16
# O32-MICROMIPS: addiu $25, $25, %lo(local_label) # encoding: [0x33,0x39,A,A]
Expand All @@ -76,17 +78,28 @@ local_label:
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]

jal weak_label
nop

# Expanding "jal weak_label":
# O32: lw $25, %call16(weak_label)($gp) # encoding: [0x8f,0x99,A,A]
# O32: # fixup A - offset: 0, value: %call16(weak_label), kind: fixup_Mips_CALL16

# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_CALL16 weak_label

# N32: lw $25, %call16(weak_label)($gp) # encoding: [0x8f,0x99,A,A]
# N32: # fixup A - offset: 0, value: %call16(weak_label), kind: fixup_Mips_CALL16

# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE weak_label

# N64: ld $25, %call16(weak_label)($gp) # encoding: [0xdf,0x99,A,A]
# N64: # fixup A - offset: 0, value: %call16(weak_label), kind: fixup_Mips_CALL16

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE weak_label

# O32-MICROMIPS: lw $25, %call16(weak_label)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS: # fixup A - offset: 0, value: %call16(weak_label), kind: fixup_MICROMIPS_CALL16

Expand All @@ -100,17 +113,28 @@ local_label:
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]

jal global_label
nop

# Expanding "jal global_label":
# O32: lw $25, %call16(global_label)($gp) # encoding: [0x8f,0x99,A,A]
# O32: # fixup A - offset: 0, value: %call16(global_label), kind: fixup_Mips_CALL16

# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_CALL16 global_label

# N32: lw $25, %call16(global_label)($gp) # encoding: [0x8f,0x99,A,A]
# N32: # fixup A - offset: 0, value: %call16(global_label), kind: fixup_Mips_CALL16

# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE global_label

# N64: ld $25, %call16(global_label)($gp) # encoding: [0xdf,0x99,A,A]
# N64: # fixup A - offset: 0, value: %call16(global_label), kind: fixup_Mips_CALL16

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE global_label

# O32-MICROMIPS: lw $25, %call16(global_label)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS: # fixup A - offset: 0, value: %call16(global_label), kind: fixup_MICROMIPS_CALL16

Expand All @@ -124,20 +148,29 @@ local_label:
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]

jal .text
nop

# FIXME: The .text section MCSymbol isn't created when printing assembly. However,
# it is created when generating an ELF object file.
# Expanding "jal .text":
# O32-FIXME: lw $25, %got(.text)($gp) # encoding: [0x8f,0x99,A,A]
# O32-FIXME: # fixup A - offset: 0, value: %got(.text), kind: fixup_Mips_GOT
# O32-FIXME: addiu $25, $25, %lo(.text) # encoding: [0x27,0x39,A,A]
# O32-FIXME: # fixup A - offset: 0, value: %lo(.text), kind: fixup_Mips_LO16
# O32-FIXME: lw $25, %call16(.text)($gp) # encoding: [0x8f,0x99,A,A]
# O32-FIXME: # fixup A - offset: 0, value: %got(.text), kind: fixup_Mips_GOT_CALL

# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_CALL16 .text

# N32-FIXME: lw $25, %call16(.text)($gp) # encoding: [0x8f,0x99,A,A]
# N32-FIXME: # fixup A - offset: 0, value: %call16(.text), kind: fixup_Mips_GOT_DISP

# N32-FIXME: lw $25, %got_disp(.text)($gp) # encoding: [0x8f,0x99,A,A]
# N32-FIXME: # fixup A - offset: 0, value: %got_disp(.text), kind: fixup_Mips_GOT_DISP
# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE .text

# N64-FIXME: ld $25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
# N64-FIXME: # fixup A - offset: 0, value: %got_disp(.text), kind: fixup_Mips_GOT_DISP
# N64-FIXME: ld $25, %call16(.text)($gp) # encoding: [0xdf,0x99,A,A]
# N64-FIXME: # fixup A - offset: 0, value: %call16(.text), kind: fixup_Mips_GOT_DISP

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE .text

# O32-MICROMIPS-FIXME: lw $25, %got(.text)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS-FIXME: # fixup A - offset: 0, value: %got(.text), kind: fixup_MICROMIPS_GOT16
Expand All @@ -154,19 +187,33 @@ local_label:
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]

# local labels ($tmp symbols)
jal 1f
nop

# Expanding "jal 1f":
# O32: lw $25, %got($tmp0)($gp) # encoding: [0x8f,0x99,A,A]
# O32: # fixup A - offset: 0, value: %got($tmp0), kind: fixup_Mips_GOT
# O32: addiu $25, $25, %lo($tmp0) # encoding: [0x27,0x39,A,A]
# O32: # fixup A - offset: 0, value: %lo($tmp0), kind: fixup_Mips_LO16

# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_GOT16 .text
# ELF-O32-NEXT: 27 39 00 54 addiu $25, $25, 84
# ELF-O32-NEXT: R_MIPS_LO16 .text

# N32: lw $25, %got_disp($tmp0)($gp) # encoding: [0x8f,0x99,A,A]
# N32: # fixup A - offset: 0, value: %got_disp($tmp0), kind: fixup_Mips_GOT_DISP

# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE .Ltmp0

# N64: ld $25, %got_disp(.Ltmp0)($gp) # encoding: [0xdf,0x99,A,A]
# N64: # fixup A - offset: 0, value: %got_disp(.Ltmp0), kind: fixup_Mips_GOT_DISP

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE .Ltmp0

# O32-MICROMIPS: lw $25, %got($tmp0)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS: # fixup A - offset: 0, value: %got($tmp0), kind: fixup_MICROMIPS_GOT16
# O32-MICROMIPS: addiu $25, $25, %lo($tmp0) # encoding: [0x33,0x39,A,A]
Expand All @@ -181,3 +228,55 @@ local_label:
# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]

.local forward_local
jal forward_local
nop

# Expanding "jal forward_local":
# O32-FIXME: lw $25, %got(forward_local)($gp) # encoding: [0x8f,0x99,A,A]
# O32-FIXME: # fixup A - offset: 0, value: %got(forward_local), kind: fixup_Mips_GOT
# O32-FIXME: addiu $25, $25, %lo(forward_local) # encoding: [0x27,0x39,A,A]
# O32-FIXME:: # fixup A - offset: 0, value: %lo(forward_local), kind: fixup_Mips_LO16

# ELF-O32: 8f 99 00 00 lw $25, 0($gp)
# ELF-O32-NEXT: R_MIPS_GOT16 .text
# ELF-O32-NEXT: 27 39 00 60 addiu $25, $25, 96
# ELF-O32-NEXT: R_MIPS_LO16 .text

# N32-FIXME: lw $25, %got_disp(forward_local)($gp) # encoding: [0x8f,0x99,A,A]
# N32-FIXME: # fixup A - offset: 0, value: %got_disp(forward_local), kind: fixup_Mips_GOT_DISP

# ELF-N32: 8f 99 00 00 lw $25, 0($gp)
# ELF-N32-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE forward_local

# N64-FIXME: ld $25, %got_disp(forward_local)($gp) # encoding: [0xdf,0x99,A,A]
# N64-FIXME: # fixup A - offset: 0, value: %got_disp(forward_local), kind: fixup_Mips_GOT_DISP

# ELF-N64: df 99 00 00 ld $25, 0($gp)
# ELF-N64-NEXT: R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE forward_local

# O32-MICROMIPS-FIXME: lw $25, %got(forward_local)($gp) # encoding: [0xff,0x3c,A,A]
# O32-MICROMIPS-FIXME: # fixup A - offset: 0, value: %got(forward_local), kind: fixup_MICROMIPS_GOT16
# O32-MICROMIPS-FIXME: addiu $25, $25, %lo(forward_local) # encoding: [0x33,0x39,A,A]
# O32-MICROMIPS-FIXME: # fixup A - offset: 0, value: %lo(forward_local), kind: fixup_MICROMIPS_LO16

# N32-MICROMIPS-FIXME: lw $25, %got_disp(forward_local)($gp) # encoding: [0xff,0x3c,A,A]
# N32-MICROMIPS-FIXME: # fixup A - offset: 0, value: %got_disp(forward_local), kind: fixup_MICROMIPS_GOT_DISP

# N64-MICROMIPS-FIXME: ld $25, %got_disp(forward_local)($gp) # encoding: [0xdf,0x99,A,A]
# N64-MICROMIPS-FIXME: # fixup A - offset: 0, value: %got_disp(forward_local), kind: fixup_MICROMIPS_GOT_DISP

# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]


.end local_label

1:
nop
add $8, $8, $8
nop
forward_local:

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