[llvm] [clang] [clang-tools-extra] [LoongArch] Insert nops and emit align reloc when handle alignment directive (PR #72962)
Lu Weining via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 23 17:16:14 PST 2024
https://github.com/SixWeining updated https://github.com/llvm/llvm-project/pull/72962
>From 4985669d2de986d595c791c04a42e84c1f080c01 Mon Sep 17 00:00:00 2001
From: Jinyang He <hejinyang at loongson.cn>
Date: Tue, 9 Jan 2024 15:35:17 +0800
Subject: [PATCH 1/2] [LoongArch] Insert nops and emit align reloc when handle
alignment directive
Refer to RISCV, we will fix up the alignment if linker relaxation changes
code size and breaks alignment. Insert enough Nops and emit R_LARCH_ALIGN
relocation type so that linker could satisfy the alignment by removing Nops.
It does so only in sections with the SHF_EXECINSTR flag.
In LoongArch psABI v2.30, R_LARCH_ALIGN requires symbol index. The
lowest 8 bits of addend represent alignment and the other bits of
addend represent the maximum number of bytes to emit.
---
.../MCTargetDesc/LoongArchAsmBackend.cpp | 69 +++++++++++++++++++
.../MCTargetDesc/LoongArchAsmBackend.h | 15 ++++
.../MCTargetDesc/LoongArchFixupKinds.h | 2 +
.../Relocations/align-non-executable.s | 22 ++++++
.../MC/LoongArch/Relocations/relax-addsub.s | 15 +++-
.../MC/LoongArch/Relocations/relax-align.s | 53 ++++++++++++++
6 files changed, 174 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/MC/LoongArch/Relocations/align-non-executable.s
create mode 100644 llvm/test/MC/LoongArch/Relocations/relax-align.s
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
index 518f6b10edabe8..0f686643622891 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
@@ -16,8 +16,11 @@
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCELFObjectWriter.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/EndianStream.h"
+#include "llvm/Support/MathExtras.h"
#define DEBUG_TYPE "loongarch-asmbackend"
@@ -174,6 +177,72 @@ void LoongArchAsmBackend::applyFixup(const MCAssembler &Asm,
}
}
+// Linker relaxation may change code size. We have to insert Nops
+// for .align directive when linker relaxation enabled. So then Linker
+// could satisfy alignment by removing Nops.
+// The function returns the total Nops Size we need to insert.
+bool LoongArchAsmBackend::shouldInsertExtraNopBytesForCodeAlign(
+ const MCAlignFragment &AF, unsigned &Size) {
+ // Calculate Nops Size only when linker relaxation enabled.
+ const MCSubtargetInfo *STI = AF.getSubtargetInfo();
+ if (!STI->hasFeature(LoongArch::FeatureRelax))
+ return false;
+
+ // Ignore alignment if the minimum Nop size is less than the MaxBytesToEmit.
+ const unsigned MinNopLen = 4;
+ if (AF.getMaxBytesToEmit() < MinNopLen)
+ return false;
+ Size = AF.getAlignment().value() - MinNopLen;
+ return AF.getAlignment() > MinNopLen;
+}
+
+// We need to insert R_LARCH_ALIGN relocation type to indicate the
+// position of Nops and the total bytes of the Nops have been inserted
+// when linker relaxation enabled.
+// The function inserts fixup_loongarch_align fixup which eventually will
+// transfer to R_LARCH_ALIGN relocation type.
+// The improved R_LARCH_ALIGN requires symbol index. The lowest 8 bits of
+// addend represent alignment and the other bits of addend represent the
+// maximum number of bytes to emit. The maximum number of bytes is zero
+// means ignore the emit limit.
+bool LoongArchAsmBackend::shouldInsertFixupForCodeAlign(
+ MCAssembler &Asm, const MCAsmLayout &Layout, MCAlignFragment &AF) {
+ // Insert the fixup only when linker relaxation enabled.
+ const MCSubtargetInfo *STI = AF.getSubtargetInfo();
+ if (!STI->hasFeature(LoongArch::FeatureRelax))
+ return false;
+
+ // Calculate total Nops we need to insert. If there are none to insert
+ // then simply return.
+ unsigned Count;
+ if (!shouldInsertExtraNopBytesForCodeAlign(AF, Count))
+ return false;
+
+ MCSection *Sec = AF.getParent();
+ MCContext &Ctx = Asm.getContext();
+ const MCExpr *Dummy = MCConstantExpr::create(0, Ctx);
+ // Create fixup_loongarch_align fixup.
+ MCFixup Fixup =
+ MCFixup::create(0, Dummy, MCFixupKind(LoongArch::fixup_loongarch_align));
+ const MCSymbolRefExpr *MCSym = getSecToAlignSym()[Sec];
+ if (MCSym == nullptr) {
+ // Create a symbol and make the value of symbol is zero.
+ MCSymbol *Sym = Ctx.createTempSymbol(".Lla-relax-align", false);
+ Sym->setFragment(&*Sec->getBeginSymbol()->getFragment());
+ Asm.registerSymbol(*Sym);
+ MCSym = MCSymbolRefExpr::create(Sym, Ctx);
+ getSecToAlignSym()[Sec] = MCSym;
+ }
+
+ uint64_t FixedValue = 0;
+ unsigned Lo = Log2_64(Count) + 1;
+ unsigned Hi = AF.getMaxBytesToEmit() >= Count ? 0 : AF.getMaxBytesToEmit();
+ MCValue Value = MCValue::get(MCSym, nullptr, Hi << 8 | Lo);
+ Asm.getWriter().recordRelocation(Asm, Layout, &AF, Fixup, Value, FixedValue);
+
+ return true;
+}
+
bool LoongArchAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
const MCFixup &Fixup,
const MCValue &Target,
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
index 71977217f59b46..0f849386648326 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
@@ -17,7 +17,9 @@
#include "MCTargetDesc/LoongArchFixupKinds.h"
#include "MCTargetDesc/LoongArchMCTargetDesc.h"
#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixupKindInfo.h"
+#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSubtargetInfo.h"
namespace llvm {
@@ -27,6 +29,7 @@ class LoongArchAsmBackend : public MCAsmBackend {
uint8_t OSABI;
bool Is64Bit;
const MCTargetOptions &TargetOptions;
+ DenseMap<MCSection *, const MCSymbolRefExpr *> SecToAlignSym;
public:
LoongArchAsmBackend(const MCSubtargetInfo &STI, uint8_t OSABI, bool Is64Bit,
@@ -45,6 +48,15 @@ class LoongArchAsmBackend : public MCAsmBackend {
uint64_t Value, bool IsResolved,
const MCSubtargetInfo *STI) const override;
+ // Return Size with extra Nop Bytes for alignment directive in code section.
+ bool shouldInsertExtraNopBytesForCodeAlign(const MCAlignFragment &AF,
+ unsigned &Size) override;
+
+ // Insert target specific fixup type for alignment directive in code section.
+ bool shouldInsertFixupForCodeAlign(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ MCAlignFragment &AF) override;
+
bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
const MCValue &Target,
const MCSubtargetInfo *STI) override;
@@ -75,6 +87,9 @@ class LoongArchAsmBackend : public MCAsmBackend {
std::unique_ptr<MCObjectTargetWriter>
createObjectTargetWriter() const override;
const MCTargetOptions &getTargetOptions() const { return TargetOptions; }
+ DenseMap<MCSection *, const MCSymbolRefExpr *> &getSecToAlignSym() {
+ return SecToAlignSym;
+ }
};
} // end namespace llvm
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
index e827bae1f3e379..0d19d2b0fb1fe8 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
@@ -109,6 +109,8 @@ enum Fixups {
fixup_loongarch_tls_gd_hi20,
// Generate an R_LARCH_RELAX which indicates the linker may relax here.
fixup_loongarch_relax = FirstLiteralRelocationKind + ELF::R_LARCH_RELAX,
+ // Generate an R_LARCH_ALIGN which indicates the linker may fixup align here.
+ fixup_loongarch_align = FirstLiteralRelocationKind + ELF::R_LARCH_ALIGN,
// 36-bit fixup corresponding to %call36(foo) for a pair instructions:
// pcaddu18i+jirl.
fixup_loongarch_call36 = FirstLiteralRelocationKind + ELF::R_LARCH_CALL36,
diff --git a/llvm/test/MC/LoongArch/Relocations/align-non-executable.s b/llvm/test/MC/LoongArch/Relocations/align-non-executable.s
new file mode 100644
index 00000000000000..4de451ffc95eda
--- /dev/null
+++ b/llvm/test/MC/LoongArch/Relocations/align-non-executable.s
@@ -0,0 +1,22 @@
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
+# RUN: | llvm-readobj -r - | FileCheck --check-prefixes=CHECK,RELAX %s
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s \
+# RUN: | llvm-readobj -r - | FileCheck %s
+
+.section ".dummy", "a"
+.L1:
+ la.pcrel $t0, sym
+.p2align 3
+.L2:
+.dword .L2 - .L1
+
+# CHECK: Relocations [
+# CHECK-NEXT: Section ({{.*}}) .rela.dummy {
+# CHECK-NEXT: 0x0 R_LARCH_PCALA_HI20 sym 0x0
+# RELAX-NEXT: 0x0 R_LARCH_RELAX - 0x0
+# CHECK-NEXT: 0x4 R_LARCH_PCALA_LO12 sym 0x0
+# RELAX-NEXT: 0x4 R_LARCH_RELAX - 0x0
+# RELAX-NEXT: 0x8 R_LARCH_ADD64 .L2 0x0
+# RELAX-NEXT: 0x8 R_LARCH_SUB64 .L1 0x0
+# CHECK-NEXT: }
+# CHECK-NEXT: ]
diff --git a/llvm/test/MC/LoongArch/Relocations/relax-addsub.s b/llvm/test/MC/LoongArch/Relocations/relax-addsub.s
index cd01332afd0bed..18e0ede5e29375 100644
--- a/llvm/test/MC/LoongArch/Relocations/relax-addsub.s
+++ b/llvm/test/MC/LoongArch/Relocations/relax-addsub.s
@@ -28,12 +28,23 @@
# RELAX: Relocations [
# RELAX-NEXT: Section ({{.*}}) .rela.text {
+# RELAX-NEXT: 0x4 R_LARCH_ALIGN {{.*}} 0x4
# RELAX-NEXT: 0x10 R_LARCH_PCALA_HI20 .L1 0x0
# RELAX-NEXT: 0x10 R_LARCH_RELAX - 0x0
# RELAX-NEXT: 0x14 R_LARCH_PCALA_LO12 .L1 0x0
# RELAX-NEXT: 0x14 R_LARCH_RELAX - 0x0
# RELAX-NEXT: }
# RELAX-NEXT: Section ({{.*}}) .rela.data {
+# RELAX-NEXT: 0x10 R_LARCH_ADD8 .L3 0x0
+# RELAX-NEXT: 0x10 R_LARCH_SUB8 .L2 0x0
+# RELAX-NEXT: 0x11 R_LARCH_ADD16 .L3 0x0
+# RELAX-NEXT: 0x11 R_LARCH_SUB16 .L2 0x0
+# RELAX-NEXT: 0x13 R_LARCH_ADD32 .L3 0x0
+# RELAX-NEXT: 0x13 R_LARCH_SUB32 .L2 0x0
+# RELAX-NEXT: 0x17 R_LARCH_ADD64 .L3 0x0
+# RELAX-NEXT: 0x17 R_LARCH_SUB64 .L2 0x0
+# RELAX-NEXT: 0x1F R_LARCH_ADD_ULEB128 .L3 0x0
+# RELAX-NEXT: 0x1F R_LARCH_SUB_ULEB128 .L2 0x0
# RELAX-NEXT: 0x20 R_LARCH_ADD8 .L4 0x0
# RELAX-NEXT: 0x20 R_LARCH_SUB8 .L3 0x0
# RELAX-NEXT: 0x21 R_LARCH_ADD16 .L4 0x0
@@ -57,7 +68,7 @@
# RELAX: Hex dump of section '.data':
# RELAX-NEXT: 0x00000000 04040004 00000004 00000000 00000004
-# RELAX-NEXT: 0x00000010 0c0c000c 0000000c 00000000 0000000c
+# RELAX-NEXT: 0x00000010 00000000 00000000 00000000 00000000
# RELAX-NEXT: 0x00000020 00000000 00000000 00000000 00000000
# RELAX-NEXT: 0x00000030 00000000 00000000 00000000 000000
@@ -78,7 +89,7 @@
.word .L2 - .L1
.dword .L2 - .L1
.uleb128 .L2 - .L1
-## TODO Handle alignment directive.
+## With relaxation, emit relocs because the .align makes the diff variable.
.byte .L3 - .L2
.short .L3 - .L2
.word .L3 - .L2
diff --git a/llvm/test/MC/LoongArch/Relocations/relax-align.s b/llvm/test/MC/LoongArch/Relocations/relax-align.s
new file mode 100644
index 00000000000000..9c7f3030e6ffb3
--- /dev/null
+++ b/llvm/test/MC/LoongArch/Relocations/relax-align.s
@@ -0,0 +1,53 @@
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s \
+# RUN: | llvm-readelf -rs - | FileCheck %s --check-prefix=NORELAX
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
+# RUN: | llvm-readelf -rs - | FileCheck %s --check-prefix=RELAX
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
+# RUN: | llvm-objdump -d - | FileCheck -check-prefix=RELAX-INST %s
+
+# NORELAX: There are no relocations in this file.
+# NORELAX: Symbol table '.symtab' contains 1 entries:
+
+# RELAX: 0000000000000000 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
+# RELAX-NEXT: 0000000000000010 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 5
+# RELAX-NEXT: 000000000000002c 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
+# RELAX-NEXT: 000000000000003c 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + b04
+# RELAX-NEXT: 0000000000000048 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
+# RELAX-EMPTY:
+# RELAX: 0000000000000000 0000000200000066 R_LARCH_ALIGN 0000000000000000 <null> + 4
+# RELAX-EMPTY:
+# RELAX: Symbol table '.symtab' contains 3 entries:
+# RELAX: 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
+# RELAX-NEXT: 1: 0000000000000000 0 NOTYPE LOCAL DEFAULT 2
+# RELAX-NEXT: 2: 0000000000000000 0 NOTYPE LOCAL DEFAULT 4
+
+.text
+.p2align 4 # A = 0x0
+nop
+.p2align 5 # B = A + 3 * NOP + NOP = 0x10
+.p2align 4 # C = B + 7 * NOP = 0x2C
+nop
+.p2align 4, , 11 # D = C + 3 * NOP + NOP = 0x3C
+## Not emit the third parameter.
+.p2align 4, , 12 # E = D + 3 * NOP = 0x48
+ # END = E + 3 * NOP = 0x54 = 21 * NOP
+
+## Not emit R_LARCH_ALIGN if code alignment great than alignment directive.
+.p2align 2
+.p2align 1
+.p2align 0
+## Not emit instructions if max emit bytes less than min nop size.
+.p2align 4, , 2
+## Not emit R_LARCH_ALIGN if alignment directive with specific padding value.
+.p2align 4, 1
+nop
+.p2align 4, 1, 12
+
+# RELAX-INST: <.text>:
+# RELAX-INST-COUNT-21: nop
+# RELAX-INST-COUNT-3: 01 01 01 01
+# RELAX-INST-NEXT: nop
+# RELAX-INST-COUNT-3: 01 01 01 01
+
+.section .text2, "ax"
+.p2align 4
>From eb4b05ebf5c8b1207e1b316cae8c3ec6a1d099d8 Mon Sep 17 00:00:00 2001
From: Jinyang He <hejinyang at loongson.cn>
Date: Tue, 23 Jan 2024 21:08:41 +0800
Subject: [PATCH 2/2] Address @SixWeining's comments and improve test.
---
.../MCTargetDesc/LoongArchAsmBackend.cpp | 10 +-
.../Relocations/align-non-executable.s | 5 +
.../MC/LoongArch/Relocations/relax-align.s | 102 +++++++++++-------
3 files changed, 73 insertions(+), 44 deletions(-)
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
index 0f686643622891..387041a8258526 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
@@ -184,11 +184,10 @@ void LoongArchAsmBackend::applyFixup(const MCAssembler &Asm,
bool LoongArchAsmBackend::shouldInsertExtraNopBytesForCodeAlign(
const MCAlignFragment &AF, unsigned &Size) {
// Calculate Nops Size only when linker relaxation enabled.
- const MCSubtargetInfo *STI = AF.getSubtargetInfo();
- if (!STI->hasFeature(LoongArch::FeatureRelax))
+ if (!AF.getSubtargetInfo()->hasFeature(LoongArch::FeatureRelax))
return false;
- // Ignore alignment if the minimum Nop size is less than the MaxBytesToEmit.
+ // Ignore alignment if MaxBytesToEmit is less than the minimum Nop size.
const unsigned MinNopLen = 4;
if (AF.getMaxBytesToEmit() < MinNopLen)
return false;
@@ -208,8 +207,7 @@ bool LoongArchAsmBackend::shouldInsertExtraNopBytesForCodeAlign(
bool LoongArchAsmBackend::shouldInsertFixupForCodeAlign(
MCAssembler &Asm, const MCAsmLayout &Layout, MCAlignFragment &AF) {
// Insert the fixup only when linker relaxation enabled.
- const MCSubtargetInfo *STI = AF.getSubtargetInfo();
- if (!STI->hasFeature(LoongArch::FeatureRelax))
+ if (!AF.getSubtargetInfo()->hasFeature(LoongArch::FeatureRelax))
return false;
// Calculate total Nops we need to insert. If there are none to insert
@@ -227,7 +225,7 @@ bool LoongArchAsmBackend::shouldInsertFixupForCodeAlign(
const MCSymbolRefExpr *MCSym = getSecToAlignSym()[Sec];
if (MCSym == nullptr) {
// Create a symbol and make the value of symbol is zero.
- MCSymbol *Sym = Ctx.createTempSymbol(".Lla-relax-align", false);
+ MCSymbol *Sym = Ctx.createNamedTempSymbol("la-relax-align");
Sym->setFragment(&*Sec->getBeginSymbol()->getFragment());
Asm.registerSymbol(*Sym);
MCSym = MCSymbolRefExpr::create(Sym, Ctx);
diff --git a/llvm/test/MC/LoongArch/Relocations/align-non-executable.s b/llvm/test/MC/LoongArch/Relocations/align-non-executable.s
index 4de451ffc95eda..47834acd9521fe 100644
--- a/llvm/test/MC/LoongArch/Relocations/align-non-executable.s
+++ b/llvm/test/MC/LoongArch/Relocations/align-non-executable.s
@@ -1,3 +1,8 @@
+## A label difference separated by an alignment directive, when the
+## referenced symbols are in a non-executable section with instructions,
+## should generate ADD/SUB relocations.
+## https://github.com/llvm/llvm-project/pull/76552
+
# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
# RUN: | llvm-readobj -r - | FileCheck --check-prefixes=CHECK,RELAX %s
# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s \
diff --git a/llvm/test/MC/LoongArch/Relocations/relax-align.s b/llvm/test/MC/LoongArch/Relocations/relax-align.s
index 9c7f3030e6ffb3..294fd9fb916c75 100644
--- a/llvm/test/MC/LoongArch/Relocations/relax-align.s
+++ b/llvm/test/MC/LoongArch/Relocations/relax-align.s
@@ -1,53 +1,79 @@
-# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s \
-# RUN: | llvm-readelf -rs - | FileCheck %s --check-prefix=NORELAX
-# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
-# RUN: | llvm-readelf -rs - | FileCheck %s --check-prefix=RELAX
-# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
-# RUN: | llvm-objdump -d - | FileCheck -check-prefix=RELAX-INST %s
-
-# NORELAX: There are no relocations in this file.
-# NORELAX: Symbol table '.symtab' contains 1 entries:
-
-# RELAX: 0000000000000000 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
-# RELAX-NEXT: 0000000000000010 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 5
-# RELAX-NEXT: 000000000000002c 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
-# RELAX-NEXT: 000000000000003c 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + b04
-# RELAX-NEXT: 0000000000000048 0000000100000066 R_LARCH_ALIGN 0000000000000000 {{.*}} + 4
-# RELAX-EMPTY:
-# RELAX: 0000000000000000 0000000200000066 R_LARCH_ALIGN 0000000000000000 <null> + 4
-# RELAX-EMPTY:
-# RELAX: Symbol table '.symtab' contains 3 entries:
-# RELAX: 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
-# RELAX-NEXT: 1: 0000000000000000 0 NOTYPE LOCAL DEFAULT 2
-# RELAX-NEXT: 2: 0000000000000000 0 NOTYPE LOCAL DEFAULT 4
+## The file testing Nop insertion with R_LARCH_ALIGN for relaxation.
+
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s -o %t
+# RUN: llvm-objdump -d %t | FileCheck %s --check-prefix=INSTR
+# RUN: llvm-readobj -r %t | FileCheck %s --check-prefix=RELOC
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s -o %t.r
+# RUN: llvm-objdump -d %t.r | FileCheck %s --check-prefixes=INSTR,RELAX-INSTR
+# RUN: llvm-readobj -r %t.r | FileCheck %s --check-prefixes=RELOC,RELAX-RELOC
.text
-.p2align 4 # A = 0x0
-nop
-.p2align 5 # B = A + 3 * NOP + NOP = 0x10
-.p2align 4 # C = B + 7 * NOP = 0x2C
-nop
-.p2align 4, , 11 # D = C + 3 * NOP + NOP = 0x3C
-## Not emit the third parameter.
-.p2align 4, , 12 # E = D + 3 * NOP = 0x48
- # END = E + 3 * NOP = 0x54 = 21 * NOP
+break 0
+# INSTR: break 0
-## Not emit R_LARCH_ALIGN if code alignment great than alignment directive.
+## Not emit R_LARCH_ALIGN if alignment directive is less than or equal to
+## minimum code alignment(a.k.a 4).
.p2align 2
.p2align 1
.p2align 0
+
## Not emit instructions if max emit bytes less than min nop size.
.p2align 4, , 2
+
## Not emit R_LARCH_ALIGN if alignment directive with specific padding value.
+## The behavior is the same as GNU assembler.
+break 1
.p2align 4, 1
-nop
+# INSTR-NEXT: break 1
+# INSTR-COUNT-2: 01 01 01 01
+
+break 2
.p2align 4, 1, 12
+# INSTR-NEXT: break 2
+# INSTR-COUNT-3: 01 01 01 01
-# RELAX-INST: <.text>:
-# RELAX-INST-COUNT-21: nop
-# RELAX-INST-COUNT-3: 01 01 01 01
-# RELAX-INST-NEXT: nop
-# RELAX-INST-COUNT-3: 01 01 01 01
+break 3
+.p2align 4
+# INSTR-NEXT: break 3
+# INSTR-COUNT-3: nop
+break 4
+.p2align 5
+.p2align 4
+# INSTR-NEXT: break 4
+# INSTR-COUNT-3: nop
+# RELAX-INSTR-COUNT-7: nop
+
+break 5
+.p2align 4, , 11
+# INSTR-NEXT: break 5
+# RELAX-INSTR-COUNT-3: nop
+
+break 6
+## Not emit the third parameter.
+.p2align 4, , 12
+# INSTR-NEXT: break 6
+# INSTR-NEXT: nop
+# INSTR-NEXT: nop
+# RELAX-INSTR-NEXT: nop
+
+ret
+# INSNR-NEXT: ret
+
+## Test the symbol index is different from .text.
.section .text2, "ax"
.p2align 4
+break 7
+
+# RELOC: Relocations [
+# RELAX-RELOC-NEXT: Section ({{.*}}) .rela.text {
+# RELAX-RELOC-NEXT: 0x24 R_LARCH_ALIGN .Lla-relax-align0 0x4
+# RELAX-RELOC-NEXT: 0x34 R_LARCH_ALIGN .Lla-relax-align0 0x5
+# RELAX-RELOC-NEXT: 0x50 R_LARCH_ALIGN .Lla-relax-align0 0x4
+# RELAX-RELOC-NEXT: 0x60 R_LARCH_ALIGN .Lla-relax-align0 0xB04
+# RELAX-RELOC-NEXT: 0x70 R_LARCH_ALIGN .Lla-relax-align0 0x4
+# RELAX-RELOC-NEXT: }
+# RELAX-RELOC-NEXT: Section ({{.*}}) .rela.text2 {
+# RELAX-RELOC-NEXT: 0x0 R_LARCH_ALIGN .Lla-relax-align1 0x4
+# RELAX-RELOC-NEXT: }
+# RELOC-NEXT: ]
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