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release/20.x: [RelLookupTableConverter] Drop unnamed_addr for GVs in entries to avoid generating GOTPCREL relocations (#146068) #146191

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release/20.x: [RelLookupTableConverter] Drop unnamed_addr for GVs in entries to avoid generating GOTPCREL relocations (#146068) #146191

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37 changes: 21 additions & 16 deletions llvm/lib/Transforms/Utils/RelLookupTableConverter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,20 @@ static bool shouldConvertToRelLookupTable(Module &M, GlobalVariable &GV) {
if (!ElemType->isPointerTy() || DL.getPointerTypeSizeInBits(ElemType) != 64)
return false;

SmallVector<GlobalVariable *, 4> GVOps;
Triple TT(M.getTargetTriple());
// FIXME: This should be removed in the future.
bool ShouldDropUnnamedAddr =
// Drop unnamed_addr to avoid matching pattern in
// `handleIndirectSymViaGOTPCRel`, which generates GOTPCREL relocations
// not supported by the GNU linker and LLD versions below 18 on aarch64.
TT.isAArch64()
// Apple's ld64 (and ld-prime on Xcode 15.2) miscompile something on
// x86_64-apple-darwin. See
// https://github.com/rust-lang/rust/issues/140686 and
// https://github.com/rust-lang/rust/issues/141306.
|| (TT.isX86() && TT.isOSDarwin());

for (const Use &Op : Array->operands()) {
Constant *ConstOp = cast<Constant>(&Op);
GlobalValue *GVOp;
Expand All @@ -86,8 +100,15 @@ static bool shouldConvertToRelLookupTable(Module &M, GlobalVariable &GV) {
!GlovalVarOp->isDSOLocal() ||
!GlovalVarOp->isImplicitDSOLocal())
return false;

if (ShouldDropUnnamedAddr)
GVOps.push_back(GlovalVarOp);
}

if (ShouldDropUnnamedAddr)
for (auto *GVOp : GVOps)
GVOp->setUnnamedAddr(GlobalValue::UnnamedAddr::None);

return true;
}

Expand All @@ -109,24 +130,8 @@ static GlobalVariable *createRelLookupTable(Function &Func,
uint64_t Idx = 0;
SmallVector<Constant *, 64> RelLookupTableContents(NumElts);

Triple TT(M.getTargetTriple());
// FIXME: This should be removed in the future.
bool ShouldDropUnnamedAddr =
// Drop unnamed_addr to avoid matching pattern in
// `handleIndirectSymViaGOTPCRel`, which generates GOTPCREL relocations
// not supported by the GNU linker and LLD versions below 18 on aarch64.
TT.isAArch64()
// Apple's ld64 (and ld-prime on Xcode 15.2) miscompile something on
// x86_64-apple-darwin. See
// https://github.com/rust-lang/rust/issues/140686 and
// https://github.com/rust-lang/rust/issues/141306.
|| (TT.isX86() && TT.isOSDarwin());

for (Use &Operand : LookupTableArr->operands()) {
Constant *Element = cast<Constant>(Operand);
if (ShouldDropUnnamedAddr)
if (auto *GlobalElement = dyn_cast<GlobalValue>(Element))
GlobalElement->setUnnamedAddr(GlobalValue::UnnamedAddr::None);
Type *IntPtrTy = M.getDataLayout().getIntPtrType(M.getContext());
Constant *Base = llvm::ConstantExpr::getPtrToInt(RelLookupTable, IntPtrTy);
Constant *Target = llvm::ConstantExpr::getPtrToInt(Element, IntPtrTy);
Expand Down
45 changes: 45 additions & 0 deletions llvm/test/Transforms/RelLookupTableConverter/unnamed_addr.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,14 @@
@y3 = internal unnamed_addr constant ptr @x0
@load_relative_2.table = private unnamed_addr constant [4 x ptr] [ptr @y3, ptr @y2, ptr @y1, ptr @y0]

@b0 = private unnamed_addr constant [8 x i8] c"00000000"
@b1 = private unnamed_addr constant [8 x i8] c"11111111"
@b2 = private unnamed_addr constant [8 x i8] c"22222222"
@load_relative_3.table = private unnamed_addr constant [3 x ptr] [
ptr getelementptr inbounds (i8, ptr @b0, i64 8),
ptr getelementptr inbounds (i8, ptr @b1, i64 8),
ptr getelementptr inbounds (i8, ptr @b2, i64 8)]

;.
; x86_64-apple-darwin: @a0 = private constant i32 0
; x86_64-apple-darwin: @a1 = private constant i32 1
Expand All @@ -34,6 +42,10 @@
; x86_64-apple-darwin: @y2 = internal constant ptr @x1
; x86_64-apple-darwin: @y3 = internal constant ptr @x0
; x86_64-apple-darwin: @load_relative_2.table.rel = private unnamed_addr constant [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @y3 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y2 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y1 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y0 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32)], align 4
; x86_64-apple-darwin: @b0 = private constant [8 x i8] c"00000000"
; x86_64-apple-darwin: @b1 = private constant [8 x i8] c"11111111"
; x86_64-apple-darwin: @b2 = private constant [8 x i8] c"22222222"
; x86_64-apple-darwin: @load_relative_3.table.rel = private unnamed_addr constant [3 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b0, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b1, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b2, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32)], align 4
;.
; aarch64: @a0 = private constant i32 0
; aarch64: @a1 = private constant i32 1
Expand All @@ -48,6 +60,10 @@
; aarch64: @y2 = internal constant ptr @x1
; aarch64: @y3 = internal constant ptr @x0
; aarch64: @load_relative_2.table.rel = private unnamed_addr constant [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @y3 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y2 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y1 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y0 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32)], align 4
; aarch64: @b0 = private constant [8 x i8] c"00000000"
; aarch64: @b1 = private constant [8 x i8] c"11111111"
; aarch64: @b2 = private constant [8 x i8] c"22222222"
; aarch64: @load_relative_3.table.rel = private unnamed_addr constant [3 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b0, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b1, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b2, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32)], align 4
;.
; x86_64: @a0 = private unnamed_addr constant i32 0
; x86_64: @a1 = private unnamed_addr constant i32 1
Expand All @@ -62,6 +78,10 @@
; x86_64: @y2 = internal unnamed_addr constant ptr @x1
; x86_64: @y3 = internal unnamed_addr constant ptr @x0
; x86_64: @load_relative_2.table.rel = private unnamed_addr constant [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @y3 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y2 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y1 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr @y0 to i64), i64 ptrtoint (ptr @load_relative_2.table.rel to i64)) to i32)], align 4
; x86_64: @b0 = private unnamed_addr constant [8 x i8] c"00000000"
; x86_64: @b1 = private unnamed_addr constant [8 x i8] c"11111111"
; x86_64: @b2 = private unnamed_addr constant [8 x i8] c"22222222"
; x86_64: @load_relative_3.table.rel = private unnamed_addr constant [3 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b0, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b1, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr getelementptr inbounds (i8, ptr @b2, i64 8) to i64), i64 ptrtoint (ptr @load_relative_3.table.rel to i64)) to i32)], align 4
;.
define ptr @load_relative_1(i64 %offset) {
; x86_64-apple-darwin-LABEL: define ptr @load_relative_1(
Expand Down Expand Up @@ -110,6 +130,31 @@ define ptr @load_relative_2(i64 %offset) {
%load = load ptr, ptr %gep
ret ptr %load
}

define ptr @load_relative_3(i64 %offset) {
; x86_64-apple-darwin-LABEL: define ptr @load_relative_3(
; x86_64-apple-darwin-SAME: i64 [[OFFSET:%.*]]) {
; x86_64-apple-darwin-NEXT: [[RELTABLE_SHIFT:%.*]] = shl i64 [[OFFSET]], 2
; x86_64-apple-darwin-NEXT: [[RELTABLE_INTRINSIC:%.*]] = call ptr @llvm.load.relative.i64(ptr @load_relative_3.table.rel, i64 [[RELTABLE_SHIFT]])
; x86_64-apple-darwin-NEXT: ret ptr [[RELTABLE_INTRINSIC]]
;
; aarch64-LABEL: define ptr @load_relative_3(
; aarch64-SAME: i64 [[OFFSET:%.*]]) {
; aarch64-NEXT: [[RELTABLE_SHIFT:%.*]] = shl i64 [[OFFSET]], 2
; aarch64-NEXT: [[RELTABLE_INTRINSIC:%.*]] = call ptr @llvm.load.relative.i64(ptr @load_relative_3.table.rel, i64 [[RELTABLE_SHIFT]])
; aarch64-NEXT: ret ptr [[RELTABLE_INTRINSIC]]
;
; x86_64-LABEL: define ptr @load_relative_3(
; x86_64-SAME: i64 [[OFFSET:%.*]]) {
; x86_64-NEXT: [[RELTABLE_SHIFT:%.*]] = shl i64 [[OFFSET]], 2
; x86_64-NEXT: [[RELTABLE_INTRINSIC:%.*]] = call ptr @llvm.load.relative.i64(ptr @load_relative_3.table.rel, i64 [[RELTABLE_SHIFT]])
; x86_64-NEXT: ret ptr [[RELTABLE_INTRINSIC]]
;
%gep = getelementptr inbounds [3 x ptr], ptr @load_relative_3.table, i64 0, i64 %offset
%load = load ptr, ptr %gep
ret ptr %load
}

;.
; x86_64-apple-darwin: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
;.
Expand Down
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