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Revert "[COFF] Use 32-bit jump table entries in .rdata for Win64" 

This reverts commit r290694. It broke sanitizer tests on Win64. I'll
probably bring this back, but the jump tables will just live in .text
like they do for MSVC.

llvm-svn: 290714
This commit is contained in:
Reid Kleckner 2016-12-29 17:07:10 +00:00
parent 00d76a5754
commit cd46c1df80
5 changed files with 9 additions and 53 deletions
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3
llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
View File

@ -156,9 +156,6 @@ public:
MCSection *getSectionForJumpTable(const Function &F,
const TargetMachine &TM) const override;
bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference,
const Function &F) const override;
/// Emit Obj-C garbage collection and linker options. Only linker option
/// emission is implemented for COFF.
void emitModuleFlags(MCStreamer &Streamer,

7
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
View File

@ -1055,13 +1055,6 @@ MCSection *TargetLoweringObjectFileCOFF::getSectionForJumpTable(
COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
}
bool TargetLoweringObjectFileCOFF::shouldPutJumpTableInFunctionSection(
bool UsesLabelDifference, const Function &F) const {
// We can always create relative relocations, so use another section
// that can be marked non-executable.
return false;
}
void TargetLoweringObjectFileCOFF::emitModuleFlags(
MCStreamer &Streamer, ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
const TargetMachine &TM) const {

25
llvm/lib/Target/X86/X86ISelLowering.cpp
View File

@ -1926,20 +1926,10 @@ unsigned X86TargetLowering::getJumpTableEncoding() const {
if (isPositionIndependent() && Subtarget.isPICStyleGOT())
return MachineJumpTableInfo::EK_Custom32;
// On Win64, we want to use both label differences and a separate section.
if (Subtarget.isTargetWin64())
return MachineJumpTableInfo::EK_LabelDifference32;
// Otherwise, use the normal jump table encoding heuristics.
return TargetLowering::getJumpTableEncoding();
}
bool X86TargetLowering::isJumpTableRelative() const {
if (Subtarget.isTargetWin64())
return true;
return TargetLowering::isJumpTableRelative();
}
bool X86TargetLowering::useSoftFloat() const {
return Subtarget.useSoftFloat();
}
@ -1958,19 +1948,11 @@ X86TargetLowering::LowerCustomJumpTableEntry(const MachineJumpTableInfo *MJTI,
/// Returns relocation base for the given PIC jumptable.
SDValue X86TargetLowering::getPICJumpTableRelocBase(SDValue Table,
SelectionDAG &DAG) const {
// COFF doesn't have relocations to take the difference between two arbitrary
// symbols. The assembler, however, can resolve a fixup between the function
// entry and a basic block label, so use the function entry as the base.
if (Subtarget.isTargetWin64())
return DAG.getGlobalAddress(DAG.getMachineFunction().getFunction(), SDLoc(),
getPointerTy(DAG.getDataLayout()));
if (!Subtarget.is64Bit())
// This doesn't have SDLoc associated with it, but is not really the
// same as a Register.
return DAG.getNode(X86ISD::GlobalBaseReg, SDLoc(),
getPointerTy(DAG.getDataLayout()));
return Table;
}
@ -1979,13 +1961,6 @@ SDValue X86TargetLowering::getPICJumpTableRelocBase(SDValue Table,
const MCExpr *X86TargetLowering::
getPICJumpTableRelocBaseExpr(const MachineFunction *MF, unsigned JTI,
MCContext &Ctx) const {
// COFF doesn't have relocations to take the difference between two arbitrary
// symbols. The assembler, however, can resolve a fixup between the function
// entry and a basic block label, so use the function entry as the base.
if (Subtarget.isTargetWin64())
return MCSymbolRefExpr::create(
getTargetMachine().getSymbol(MF->getFunction()), Ctx);
// X86-64 uses RIP relative addressing based on the jump table label.
if (Subtarget.isPICStyleRIPRel())
return TargetLowering::getPICJumpTableRelocBaseExpr(MF, JTI, Ctx);

1
llvm/lib/Target/X86/X86ISelLowering.h
View File

@ -684,7 +684,6 @@ namespace llvm {
const X86Subtarget &STI);
unsigned getJumpTableEncoding() const override;
bool isJumpTableRelative() const override;
bool useSoftFloat() const override;
MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {

26
llvm/test/CodeGen/X86/win64-jumptable.ll
View File

@ -1,5 +1,7 @@
; RUN: llc < %s -relocation-model static | FileCheck %s --check-prefix=CHECK --check-prefix=STATIC
; RUN: llc < %s -relocation-model pic | FileCheck %s --check-prefix=CHECK --check-prefix=PIC
; RUN: llc < %s -relocation-model static | FileCheck %s
; FIXME: Remove '-relocation-model static' when it is no longer necessary to
; trigger the separate .rdata section.
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc19.0.24215"
@ -39,17 +41,7 @@ declare void @g(i32)
; CHECK: .text
; CHECK: f:
; CHECK: .seh_proc f
; STATIC: movslq .LJTI0_0(,%{{.*}},4), %[[target:[^ ]*]]
; STATIC: leaq f(%[[target]]), %[[target]]
; STATIC: jmpq *%[[target]]
; PIC: leaq .LJTI0_0(%rip), %[[jt:[^ ]*]]
; PIC: movslq (%[[jt]],%{{.*}},4), %[[offset:[^ ]*]]
; PIC: leaq f(%rip), %[[base:[^ ]*]]
; PIC: addq %[[offset]], %[[base]]
; PIC: jmpq *%[[base]]
; CHECK: jmpq *.LJTI0_0
; CHECK: .LBB0_{{.*}}: # %sw.bb
; CHECK: .LBB0_{{.*}}: # %sw.bb1
; CHECK: .LBB0_{{.*}}: # %sw.bb2
@ -57,10 +49,10 @@ declare void @g(i32)
; CHECK: callq g
; CHECK: jmp g # TAILCALL
; CHECK: .section .rdata,"dr"
; CHECK: .long .LBB0_{{.*}}-f
; CHECK: .long .LBB0_{{.*}}-f
; CHECK: .long .LBB0_{{.*}}-f
; CHECK: .long .LBB0_{{.*}}-f
; CHECK: .quad .LBB0_
; CHECK: .quad .LBB0_
; CHECK: .quad .LBB0_
; CHECK: .quad .LBB0_
; CHECK: .seh_handlerdata
; It's important that we switch back to .text here, not .rdata.