CodeGen: Emit .prefalign directives based on the prefalign attribute. #155529
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Created using spr 1.3.6-beta.1
llvmbot
added
backend:PowerPC
backend:X86
llvm:codegen
PGO
|
@llvm/pr-subscribers-lld @llvm/pr-subscribers-backend-x86 Author: Peter Collingbourne (pcc) ChangesMachineFunction can now be queried for the preferred alignment which Part of this RFC: Full diff: https://github.com/llvm/llvm-project/pull/155529.diff 8 Files Affected:
diff --git a/llvm/include/llvm/CodeGen/MachineFunction.h b/llvm/include/llvm/CodeGen/MachineFunction.h
index ef783f276b7d4..a454ad02df23d 100644
--- a/llvm/include/llvm/CodeGen/MachineFunction.h
+++ b/llvm/include/llvm/CodeGen/MachineFunction.h
@@ -818,6 +818,8 @@ class LLVM_ABI MachineFunction {
Alignment = A;
}
+ Align getPreferredAlignment() const;
+
/// exposesReturnsTwice - Returns true if the function calls setjmp or
/// any other similar functions with attribute "returns twice" without
/// having the attribute itself.
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index cd14a4f57f760..25037651b92ea 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -977,8 +977,20 @@ void AsmPrinter::emitFunctionHeader() {
emitVisibility(CurrentFnSym, F.getVisibility());
emitLinkage(&F, CurrentFnSym);
- if (MAI->hasFunctionAlignment())
- emitAlignment(MF->getAlignment(), &F);
+ if (MAI->hasFunctionAlignment()) {
+ // The preferred alignment directive will not have the intended effect
+ // unless function sections are enabled.
+ if (MAI->useIntegratedAssembler() && MAI->hasPreferredAlignment() &&
+ TM.getFunctionSections()) {
+ Align Alignment = MF->getAlignment();
+ Align PrefAlignment = MF->getPreferredAlignment();
+ emitAlignment(Alignment, &F);
+ if (Alignment != PrefAlignment)
+ OutStreamer->emitPrefAlign(PrefAlignment);
+ } else {
+ emitAlignment(MF->getPreferredAlignment(), &F);
+ }
+ }
if (MAI->hasDotTypeDotSizeDirective())
OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index 13fd270ec7410..90d8196ffb82a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -204,8 +204,8 @@ void WinException::beginFunclet(const MachineBasicBlock &MBB,
// We want our funclet's entry point to be aligned such that no nops will be
// present after the label.
- Asm->emitAlignment(std::max(Asm->MF->getAlignment(), MBB.getAlignment()),
- &F);
+ Asm->emitAlignment(
+ std::max(Asm->MF->getPreferredAlignment(), MBB.getAlignment()), &F);
// Now that we've emitted the alignment directive, point at our funclet.
Asm->OutStreamer->emitLabel(Sym);
diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index 224231cb90fe2..eabe1a510d92d 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -211,11 +211,6 @@ void MachineFunction::init() {
ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
Alignment = STI.getTargetLowering()->getMinFunctionAlignment();
- // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
- if (!F.hasOptSize())
- Alignment = std::max(Alignment,
- STI.getTargetLowering()->getPrefFunctionAlignment());
-
// -fsanitize=function and -fsanitize=kcfi instrument indirect function calls
// to load a type hash before the function label. Ensure functions are aligned
// by a least 4 to avoid unaligned access, which is especially important for
@@ -330,6 +325,18 @@ bool MachineFunction::shouldSplitStack() const {
return getFunction().hasFnAttribute("split-stack");
}
+Align MachineFunction::getPreferredAlignment() const {
+ Align PrefAlignment = Align(1);
+
+ if (!F.hasOptSize())
+ PrefAlignment = STI.getTargetLowering()->getPrefFunctionAlignment();
+
+ if (MaybeAlign A = F.getPreferredAlignment())
+ PrefAlignment = *A;
+
+ return std::max(PrefAlignment, getAlignment());
+}
+
[[nodiscard]] unsigned
MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
FrameInstructions.push_back(Inst);
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index d406277e440bb..0912afa098b75 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -155,7 +155,7 @@ void X86AsmPrinter::EmitKCFITypePadding(const MachineFunction &MF,
if (HasType)
PrefixBytes += 5;
- emitNops(offsetToAlignment(PrefixBytes, MF.getAlignment()));
+ emitNops(offsetToAlignment(PrefixBytes, MF.getPreferredAlignment()));
}
/// emitKCFITypeId - Emit the KCFI type information in architecture specific
diff --git a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
index cbcfd9a6a0dab..bd88b5d89202d 100644
--- a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
+++ b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
@@ -26,7 +26,7 @@ entry:
declare signext i32 @do_something(ptr)
; CHECK: name: test
-; CHECK: alignment: 16
+; CHECK: alignment: 4
; CHECK: liveins:
; CHECK64: - { reg: '$x3', virtual-reg: '' }
; CHECK32: - { reg: '$r3', virtual-reg: '' }
diff --git a/llvm/test/CodeGen/X86/prefalign.ll b/llvm/test/CodeGen/X86/prefalign.ll
new file mode 100644
index 0000000000000..9a775bc328c60
--- /dev/null
+++ b/llvm/test/CodeGen/X86/prefalign.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s | FileCheck --check-prefixes=CHECK,NOFS %s
+; RUN: llc -function-sections < %s | FileCheck --check-prefixes=CHECK,FS %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: .globl f1
+; NOFS-NEXT: .p2align 4
+; FS-NEXT: .prefalign 16
+define void @f1() {
+ ret void
+}
+
+; CHECK: .globl f2
+; CHECK-NOT: .prefalign
+; CHECK-NOT: .p2align
+define void @f2() prefalign 1 {
+ ret void
+}
+
+; CHECK: .globl f3
+; NOFS-NEXT: .p2align 2
+; FS-NEXT: .p2align 1
+; FS-NEXT: .prefalign 4
+define void @f3() align 2 prefalign 4 {
+ ret void
+}
diff --git a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
index 62d3d8255a175..4143b0ef580ba 100644
--- a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
+++ b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
@@ -107,7 +107,7 @@ entry:
; CHECK-SEC: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC: [ 3] .text.foo PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC: [ 5] .text.foo2 PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
@@ -135,7 +135,7 @@ entry:
; CHECK-SEC2: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC2: [ 3] .text PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC2: [ 5] .text PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC2-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC2: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC2-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
|
|
@llvm/pr-subscribers-llvm-transforms Author: Peter Collingbourne (pcc) ChangesMachineFunction can now be queried for the preferred alignment which Part of this RFC: Full diff: https://github.com/llvm/llvm-project/pull/155529.diff 8 Files Affected:
diff --git a/llvm/include/llvm/CodeGen/MachineFunction.h b/llvm/include/llvm/CodeGen/MachineFunction.h
index ef783f276b7d4..a454ad02df23d 100644
--- a/llvm/include/llvm/CodeGen/MachineFunction.h
+++ b/llvm/include/llvm/CodeGen/MachineFunction.h
@@ -818,6 +818,8 @@ class LLVM_ABI MachineFunction {
Alignment = A;
}
+ Align getPreferredAlignment() const;
+
/// exposesReturnsTwice - Returns true if the function calls setjmp or
/// any other similar functions with attribute "returns twice" without
/// having the attribute itself.
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index cd14a4f57f760..25037651b92ea 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -977,8 +977,20 @@ void AsmPrinter::emitFunctionHeader() {
emitVisibility(CurrentFnSym, F.getVisibility());
emitLinkage(&F, CurrentFnSym);
- if (MAI->hasFunctionAlignment())
- emitAlignment(MF->getAlignment(), &F);
+ if (MAI->hasFunctionAlignment()) {
+ // The preferred alignment directive will not have the intended effect
+ // unless function sections are enabled.
+ if (MAI->useIntegratedAssembler() && MAI->hasPreferredAlignment() &&
+ TM.getFunctionSections()) {
+ Align Alignment = MF->getAlignment();
+ Align PrefAlignment = MF->getPreferredAlignment();
+ emitAlignment(Alignment, &F);
+ if (Alignment != PrefAlignment)
+ OutStreamer->emitPrefAlign(PrefAlignment);
+ } else {
+ emitAlignment(MF->getPreferredAlignment(), &F);
+ }
+ }
if (MAI->hasDotTypeDotSizeDirective())
OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index 13fd270ec7410..90d8196ffb82a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -204,8 +204,8 @@ void WinException::beginFunclet(const MachineBasicBlock &MBB,
// We want our funclet's entry point to be aligned such that no nops will be
// present after the label.
- Asm->emitAlignment(std::max(Asm->MF->getAlignment(), MBB.getAlignment()),
- &F);
+ Asm->emitAlignment(
+ std::max(Asm->MF->getPreferredAlignment(), MBB.getAlignment()), &F);
// Now that we've emitted the alignment directive, point at our funclet.
Asm->OutStreamer->emitLabel(Sym);
diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index 224231cb90fe2..eabe1a510d92d 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -211,11 +211,6 @@ void MachineFunction::init() {
ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
Alignment = STI.getTargetLowering()->getMinFunctionAlignment();
- // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
- if (!F.hasOptSize())
- Alignment = std::max(Alignment,
- STI.getTargetLowering()->getPrefFunctionAlignment());
-
// -fsanitize=function and -fsanitize=kcfi instrument indirect function calls
// to load a type hash before the function label. Ensure functions are aligned
// by a least 4 to avoid unaligned access, which is especially important for
@@ -330,6 +325,18 @@ bool MachineFunction::shouldSplitStack() const {
return getFunction().hasFnAttribute("split-stack");
}
+Align MachineFunction::getPreferredAlignment() const {
+ Align PrefAlignment = Align(1);
+
+ if (!F.hasOptSize())
+ PrefAlignment = STI.getTargetLowering()->getPrefFunctionAlignment();
+
+ if (MaybeAlign A = F.getPreferredAlignment())
+ PrefAlignment = *A;
+
+ return std::max(PrefAlignment, getAlignment());
+}
+
[[nodiscard]] unsigned
MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
FrameInstructions.push_back(Inst);
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index d406277e440bb..0912afa098b75 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -155,7 +155,7 @@ void X86AsmPrinter::EmitKCFITypePadding(const MachineFunction &MF,
if (HasType)
PrefixBytes += 5;
- emitNops(offsetToAlignment(PrefixBytes, MF.getAlignment()));
+ emitNops(offsetToAlignment(PrefixBytes, MF.getPreferredAlignment()));
}
/// emitKCFITypeId - Emit the KCFI type information in architecture specific
diff --git a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
index cbcfd9a6a0dab..bd88b5d89202d 100644
--- a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
+++ b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
@@ -26,7 +26,7 @@ entry:
declare signext i32 @do_something(ptr)
; CHECK: name: test
-; CHECK: alignment: 16
+; CHECK: alignment: 4
; CHECK: liveins:
; CHECK64: - { reg: '$x3', virtual-reg: '' }
; CHECK32: - { reg: '$r3', virtual-reg: '' }
diff --git a/llvm/test/CodeGen/X86/prefalign.ll b/llvm/test/CodeGen/X86/prefalign.ll
new file mode 100644
index 0000000000000..9a775bc328c60
--- /dev/null
+++ b/llvm/test/CodeGen/X86/prefalign.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s | FileCheck --check-prefixes=CHECK,NOFS %s
+; RUN: llc -function-sections < %s | FileCheck --check-prefixes=CHECK,FS %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: .globl f1
+; NOFS-NEXT: .p2align 4
+; FS-NEXT: .prefalign 16
+define void @f1() {
+ ret void
+}
+
+; CHECK: .globl f2
+; CHECK-NOT: .prefalign
+; CHECK-NOT: .p2align
+define void @f2() prefalign 1 {
+ ret void
+}
+
+; CHECK: .globl f3
+; NOFS-NEXT: .p2align 2
+; FS-NEXT: .p2align 1
+; FS-NEXT: .prefalign 4
+define void @f3() align 2 prefalign 4 {
+ ret void
+}
diff --git a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
index 62d3d8255a175..4143b0ef580ba 100644
--- a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
+++ b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
@@ -107,7 +107,7 @@ entry:
; CHECK-SEC: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC: [ 3] .text.foo PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC: [ 5] .text.foo2 PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
@@ -135,7 +135,7 @@ entry:
; CHECK-SEC2: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC2: [ 3] .text PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC2: [ 5] .text PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC2-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC2: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC2-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
|
|
@llvm/pr-subscribers-pgo Author: Peter Collingbourne (pcc) ChangesMachineFunction can now be queried for the preferred alignment which Part of this RFC: Full diff: https://github.com/llvm/llvm-project/pull/155529.diff 8 Files Affected:
diff --git a/llvm/include/llvm/CodeGen/MachineFunction.h b/llvm/include/llvm/CodeGen/MachineFunction.h
index ef783f276b7d4..a454ad02df23d 100644
--- a/llvm/include/llvm/CodeGen/MachineFunction.h
+++ b/llvm/include/llvm/CodeGen/MachineFunction.h
@@ -818,6 +818,8 @@ class LLVM_ABI MachineFunction {
Alignment = A;
}
+ Align getPreferredAlignment() const;
+
/// exposesReturnsTwice - Returns true if the function calls setjmp or
/// any other similar functions with attribute "returns twice" without
/// having the attribute itself.
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index cd14a4f57f760..25037651b92ea 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -977,8 +977,20 @@ void AsmPrinter::emitFunctionHeader() {
emitVisibility(CurrentFnSym, F.getVisibility());
emitLinkage(&F, CurrentFnSym);
- if (MAI->hasFunctionAlignment())
- emitAlignment(MF->getAlignment(), &F);
+ if (MAI->hasFunctionAlignment()) {
+ // The preferred alignment directive will not have the intended effect
+ // unless function sections are enabled.
+ if (MAI->useIntegratedAssembler() && MAI->hasPreferredAlignment() &&
+ TM.getFunctionSections()) {
+ Align Alignment = MF->getAlignment();
+ Align PrefAlignment = MF->getPreferredAlignment();
+ emitAlignment(Alignment, &F);
+ if (Alignment != PrefAlignment)
+ OutStreamer->emitPrefAlign(PrefAlignment);
+ } else {
+ emitAlignment(MF->getPreferredAlignment(), &F);
+ }
+ }
if (MAI->hasDotTypeDotSizeDirective())
OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index 13fd270ec7410..90d8196ffb82a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -204,8 +204,8 @@ void WinException::beginFunclet(const MachineBasicBlock &MBB,
// We want our funclet's entry point to be aligned such that no nops will be
// present after the label.
- Asm->emitAlignment(std::max(Asm->MF->getAlignment(), MBB.getAlignment()),
- &F);
+ Asm->emitAlignment(
+ std::max(Asm->MF->getPreferredAlignment(), MBB.getAlignment()), &F);
// Now that we've emitted the alignment directive, point at our funclet.
Asm->OutStreamer->emitLabel(Sym);
diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index 224231cb90fe2..eabe1a510d92d 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -211,11 +211,6 @@ void MachineFunction::init() {
ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
Alignment = STI.getTargetLowering()->getMinFunctionAlignment();
- // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
- if (!F.hasOptSize())
- Alignment = std::max(Alignment,
- STI.getTargetLowering()->getPrefFunctionAlignment());
-
// -fsanitize=function and -fsanitize=kcfi instrument indirect function calls
// to load a type hash before the function label. Ensure functions are aligned
// by a least 4 to avoid unaligned access, which is especially important for
@@ -330,6 +325,18 @@ bool MachineFunction::shouldSplitStack() const {
return getFunction().hasFnAttribute("split-stack");
}
+Align MachineFunction::getPreferredAlignment() const {
+ Align PrefAlignment = Align(1);
+
+ if (!F.hasOptSize())
+ PrefAlignment = STI.getTargetLowering()->getPrefFunctionAlignment();
+
+ if (MaybeAlign A = F.getPreferredAlignment())
+ PrefAlignment = *A;
+
+ return std::max(PrefAlignment, getAlignment());
+}
+
[[nodiscard]] unsigned
MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
FrameInstructions.push_back(Inst);
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index d406277e440bb..0912afa098b75 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -155,7 +155,7 @@ void X86AsmPrinter::EmitKCFITypePadding(const MachineFunction &MF,
if (HasType)
PrefixBytes += 5;
- emitNops(offsetToAlignment(PrefixBytes, MF.getAlignment()));
+ emitNops(offsetToAlignment(PrefixBytes, MF.getPreferredAlignment()));
}
/// emitKCFITypeId - Emit the KCFI type information in architecture specific
diff --git a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
index cbcfd9a6a0dab..bd88b5d89202d 100644
--- a/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
+++ b/llvm/test/CodeGen/PowerPC/alloca-crspill.ll
@@ -26,7 +26,7 @@ entry:
declare signext i32 @do_something(ptr)
; CHECK: name: test
-; CHECK: alignment: 16
+; CHECK: alignment: 4
; CHECK: liveins:
; CHECK64: - { reg: '$x3', virtual-reg: '' }
; CHECK32: - { reg: '$r3', virtual-reg: '' }
diff --git a/llvm/test/CodeGen/X86/prefalign.ll b/llvm/test/CodeGen/X86/prefalign.ll
new file mode 100644
index 0000000000000..9a775bc328c60
--- /dev/null
+++ b/llvm/test/CodeGen/X86/prefalign.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s | FileCheck --check-prefixes=CHECK,NOFS %s
+; RUN: llc -function-sections < %s | FileCheck --check-prefixes=CHECK,FS %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: .globl f1
+; NOFS-NEXT: .p2align 4
+; FS-NEXT: .prefalign 16
+define void @f1() {
+ ret void
+}
+
+; CHECK: .globl f2
+; CHECK-NOT: .prefalign
+; CHECK-NOT: .p2align
+define void @f2() prefalign 1 {
+ ret void
+}
+
+; CHECK: .globl f3
+; NOFS-NEXT: .p2align 2
+; FS-NEXT: .p2align 1
+; FS-NEXT: .prefalign 4
+define void @f3() align 2 prefalign 4 {
+ ret void
+}
diff --git a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
index 62d3d8255a175..4143b0ef580ba 100644
--- a/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
+++ b/llvm/test/Transforms/SampleProfile/pseudo-probe-emit.ll
@@ -107,7 +107,7 @@ entry:
; CHECK-SEC: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC: [ 3] .text.foo PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC: [ 5] .text.foo2 PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC: [ 8] .text.foo3 PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
@@ -135,7 +135,7 @@ entry:
; CHECK-SEC2: [Nr] Name Type {{.*}} ES Flg Lk Inf Al
; CHECK-SEC2: [ 3] .text PROGBITS {{.*}} 00 AX 0 0 16
; CHECK-SEC2: [ 5] .text PROGBITS {{.*}} 00 AX 0 0 16
-; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 16
+; CHECK-SEC2: [ 8] .text PROGBITS {{.*}} 00 AXG 0 0 1
; CHECK-SEC2-COUNT-3: .pseudo_probe_desc PROGBITS
; CHECK-SEC2: .pseudo_probe PROGBITS {{.*}} 00 L 3 0 1
; CHECK-SEC2-NEXT: .pseudo_probe PROGBITS {{.*}} 00 L 5 0 1
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✅ With the latest revision this PR passed the C/C++ code formatter. |
Created using spr 1.3.6-beta.1
MaskRay
reviewed
Aug 27, 2025
llvm/lib/CodeGen/MachineFunction.cpp
Outdated
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| Align MachineFunction::getPreferredAlignment() const { | ||
| Align PrefAlignment = Align(1); |
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Instead of reassigning to the variable multiple times, it's better to reverse the order the following two conditions
Created using spr 1.3.6-beta.1
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Ping |
Done: #158368 |
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The result of the MachineFunction preferred alignment query is emitted
as a .prefalign directive if supported, otherwise it gets combined into
the minimum alignment.
Part of this RFC:
https://discourse.llvm.org/t/rfc-enhancing-function-alignment-attributes/88019