[llvm] 3659780 - MachineModuleInfo: Remove UsesMorestackAddr
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 20 08:10:28 PDT 2022
Author: Matt Arsenault
Date: 2022-04-20T11:10:20-04:00
New Revision: 3659780d58722ea38adf25f7116151f2ecf2d521
URL: https://github.com/llvm/llvm-project/commit/3659780d58722ea38adf25f7116151f2ecf2d521
DIFF: https://github.com/llvm/llvm-project/commit/3659780d58722ea38adf25f7116151f2ecf2d521.diff
LOG: MachineModuleInfo: Remove UsesMorestackAddr
This is x86 specific, and adds statefulness to
MachineModuleInfo. Instead of explicitly tracking this, infer if we
need to declare the symbol based on the reference previously inserted.
This produces a small change in the output due to the move from
AsmPrinter::doFinalization to X86's emitEndOfAsmFile. This will now be
moved relative to other end of file fields, which I'm assuming doesn't
matter (e.g. the __morestack_addr declaration is now after the
.note.GNU-split-stack part)
This also produces another small change in code if the module happened
to define/declare __morestack_addr, but I assume that's invalid and
doesn't really matter.
Added:
llvm/test/CodeGen/X86/morestack-decl.ll
Modified:
llvm/include/llvm/CodeGen/MachineModuleInfo.h
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/CodeGen/MachineModuleInfo.cpp
llvm/lib/Target/X86/X86AsmPrinter.cpp
llvm/lib/Target/X86/X86FrameLowering.cpp
llvm/test/CodeGen/X86/segmented-stacks.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/MachineModuleInfo.h b/llvm/include/llvm/CodeGen/MachineModuleInfo.h
index 88951266dc3a0..0f5ff18e3dc26 100644
--- a/llvm/include/llvm/CodeGen/MachineModuleInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineModuleInfo.h
@@ -123,12 +123,6 @@ class MachineModuleInfo {
/// point. This is used to emit an undefined reference to _fltused.
bool UsesMSVCFloatingPoint;
- /// True if the module calls the __morestack function indirectly, as is
- /// required under the large code model on x86. This is used to emit
- /// a definition of a symbol, __morestack_addr, containing the address. See
- /// comments in lib/Target/X86/X86FrameLowering.cpp for more details.
- bool UsesMorestackAddr;
-
/// Maps IR Functions to their corresponding MachineFunctions.
DenseMap<const Function*, std::unique_ptr<MachineFunction>> MachineFunctions;
/// Next unique number available for a MachineFunction.
@@ -195,14 +189,6 @@ class MachineModuleInfo {
void setUsesMSVCFloatingPoint(bool b) { UsesMSVCFloatingPoint = b; }
- bool usesMorestackAddr() const {
- return UsesMorestackAddr;
- }
-
- void setUsesMorestackAddr(bool b) {
- UsesMorestackAddr = b;
- }
-
/// Return the symbol to be used for the specified basic block when its
/// address is taken. This cannot be its normal LBB label because the block
/// may be accessed outside its containing function.
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 5e697be9581ba..ab7cfc877dd8a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1904,23 +1904,6 @@ bool AsmPrinter::doFinalization(Module &M) {
// Emit bytes for llvm.commandline metadata.
emitModuleCommandLines(M);
- // Emit __morestack address if needed for indirect calls.
- if (MMI->usesMorestackAddr()) {
- Align Alignment(1);
- MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
- getDataLayout(), SectionKind::getReadOnly(),
- /*C=*/nullptr, Alignment);
- OutStreamer->SwitchSection(ReadOnlySection);
-
- MCSymbol *AddrSymbol =
- OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
- OutStreamer->emitLabel(AddrSymbol);
-
- unsigned PtrSize = MAI->getCodePointerSize();
- OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("__morestack"),
- PtrSize);
- }
-
// Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
// split-stack is used.
if (TM.getTargetTriple().isOSBinFormatELF() && HasSplitStack) {
diff --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp
index 1e1b9e9c08a20..7b96a31d0cd49 100644
--- a/llvm/lib/CodeGen/MachineModuleInfo.cpp
+++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp
@@ -202,7 +202,7 @@ void MachineModuleInfo::initialize() {
ObjFileMMI = nullptr;
CurCallSite = 0;
NextFnNum = 0;
- UsesMSVCFloatingPoint = UsesMorestackAddr = false;
+ UsesMSVCFloatingPoint = false;
AddrLabelSymbols = nullptr;
DbgInfoAvailable = false;
}
@@ -230,7 +230,6 @@ MachineModuleInfo::MachineModuleInfo(MachineModuleInfo &&MMI)
ObjFileMMI = MMI.ObjFileMMI;
CurCallSite = MMI.CurCallSite;
UsesMSVCFloatingPoint = MMI.UsesMSVCFloatingPoint;
- UsesMorestackAddr = MMI.UsesMorestackAddr;
AddrLabelSymbols = MMI.AddrLabelSymbols;
ExternalContext = MMI.ExternalContext;
TheModule = MMI.TheModule;
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index cfa639ea86ec0..46f258a7163b4 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -29,6 +29,7 @@
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
+#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
@@ -803,6 +804,22 @@ void X86AsmPrinter::emitEndOfAsmFile(Module &M) {
emitStackMaps(SM);
FM.serializeToFaultMapSection();
}
+
+ // Emit __morestack address if needed for indirect calls.
+ if (TT.getArch() == Triple::x86_64 && TM.getCodeModel() == CodeModel::Large) {
+ if (MCSymbol *AddrSymbol = OutContext.lookupSymbol("__morestack_addr")) {
+ Align Alignment(1);
+ MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
+ getDataLayout(), SectionKind::getReadOnly(),
+ /*C=*/nullptr, Alignment);
+ OutStreamer->SwitchSection(ReadOnlySection);
+ OutStreamer->emitLabel(AddrSymbol);
+
+ unsigned PtrSize = MAI->getCodePointerSize();
+ OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("__morestack"),
+ PtrSize);
+ }
+ }
}
//===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 1086e0ac72d0e..005ccad0afef7 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -3128,7 +3128,6 @@ void X86FrameLowering::adjustForSegmentedStacks(
.addReg(0)
.addExternalSymbol("__morestack_addr")
.addReg(0);
- MF.getMMI().setUsesMorestackAddr(true);
} else {
if (Is64Bit)
BuildMI(allocMBB, DL, TII.get(X86::CALL64pcrel32))
diff --git a/llvm/test/CodeGen/X86/morestack-decl.ll b/llvm/test/CodeGen/X86/morestack-decl.ll
new file mode 100644
index 0000000000000..d3b44137da5ba
--- /dev/null
+++ b/llvm/test/CodeGen/X86/morestack-decl.ll
@@ -0,0 +1,10 @@
+; RUN: llc -mcpu=generic -mtriple=x86_64-linux -code-model=large < %s | FileCheck %s
+
+; Check what happens if we have an existing declaration of __morestack_addr
+
+; CHECK: .section ".note.GNU-stack","", at progbits
+; CHECK-NEXT: .section .rodata,"a", at progbits
+; CHECK-NEXT: __morestack_addr:
+; CHECK-NEXT: .quad __morestack
+
+declare void @__morestack_addr()
diff --git a/llvm/test/CodeGen/X86/segmented-stacks.ll b/llvm/test/CodeGen/X86/segmented-stacks.ll
index f9dcc9faf831a..29ba9924e4ce3 100644
--- a/llvm/test/CodeGen/X86/segmented-stacks.ll
+++ b/llvm/test/CodeGen/X86/segmented-stacks.ll
@@ -2123,7 +2123,10 @@ define i32 @test_nested_unused(i32 * nest %unused) #0 {
attributes #0 = { "split-stack" }
-; X64-Linux-Large: .rodata
+; X64-Linux-Large: .section ".note.GNU-split-stack","", at progbits
+; X64-Linux-Large-NEXT: .section ".note.GNU-no-split-stack","", at progbits
+; X64-Linux-Large-NEXT: .section ".note.GNU-stack","", at progbits
+; X64-Linux-Large-NEXT: .rodata
; X64-Linux-Large-NEXT: __morestack_addr:
; X64-Linux-Large-NEXT: .quad __morestack
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