[WebAssembly] Remove wasm-specific TLS builtins

[sbc100]

Summary

These builtins don't have any actual users in the real
world. We can add these back later if we find a genuine
use for them.

[tlively]

Excellent, thanks. I hope I'm not forgetting any good reason we added these. Emscripten doesn't use them in its pthreads runtime, right?

[sbc100]

I don't think so but I will double check.

I'm in the middle of some TLS rethinking so I'll leave this open for now pending any changes to our TLS ABI.

[sbc100]

Nope I was wrong, emscripten does use these.

clang/include/clang/Basic/BuiltinsWebAssembly.def

 #endif
 
 // Query the current memory size, and increase the current memory size.
 // Note that memory.size is not "c" (readnone) because it must be sequenced
 // with respect to memory.grow calls.
 BUILTIN(__builtin_wasm_memory_size, "zIi", "n")
 BUILTIN(__builtin_wasm_memory_grow, "zIiz", "n")
 
-// Thread-local storage
-TARGET_BUILTIN(__builtin_wasm_tls_size, "z", "nc", "bulk-memory")
-TARGET_BUILTIN(__builtin_wasm_tls_align, "z", "nc", "bulk-memory")
-TARGET_BUILTIN(__builtin_wasm_tls_base, "v*", "nU", "bulk-memory")
-
 // Floating point min/max
 BUILTIN(__builtin_wasm_min_f32, "fff", "nc")
 BUILTIN(__builtin_wasm_max_f32, "fff", "nc")
 BUILTIN(__builtin_wasm_min_f64, "ddd", "nc")
 BUILTIN(__builtin_wasm_max_f64, "ddd", "nc")
 
 // Exception handling builtins.
 TARGET_BUILTIN(__builtin_wasm_throw, "vIUiv*", "r", "exception-handling")

clang/lib/CodeGen/CGBuiltin.cpp

Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
   case WebAssembly::BI__builtin_wasm_memory_grow: {
     llvm::Type *ResultType = ConvertType(E->getType());
     Value *Args[] = {EmitScalarExpr(E->getArg(0)),
                      EmitScalarExpr(E->getArg(1))};
     Function *Callee =
         CGM.getIntrinsic(Intrinsic::wasm_memory_grow, ResultType);
     return Builder.CreateCall(Callee, Args);
   }
-  case WebAssembly::BI__builtin_wasm_tls_size: {
-    llvm::Type *ResultType = ConvertType(E->getType());
-    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_tls_size, ResultType);
-    return Builder.CreateCall(Callee);
-  }
-  case WebAssembly::BI__builtin_wasm_tls_align: {
-    llvm::Type *ResultType = ConvertType(E->getType());
-    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_tls_align, ResultType);
-    return Builder.CreateCall(Callee);
-  }
-  case WebAssembly::BI__builtin_wasm_tls_base: {
-    Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_tls_base);
-    return Builder.CreateCall(Callee);
-  }
   case WebAssembly::BI__builtin_wasm_throw: {
     Value *Tag = EmitScalarExpr(E->getArg(0));
     Value *Obj = EmitScalarExpr(E->getArg(1));
     Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_throw);
     return Builder.CreateCall(Callee, {Tag, Obj});
   }
   case WebAssembly::BI__builtin_wasm_rethrow_in_catch: {
     Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_rethrow_in_catch);

clang/test/CodeGen/builtins-wasm.c

 }
 
 __SIZE_TYPE__ memory_grow(__SIZE_TYPE__ delta) {
   return __builtin_wasm_memory_grow(0, delta);
   // WEBASSEMBLY32: call i32 @llvm.wasm.memory.grow.i32(i32 0, i32 %{{.*}})
   // WEBASSEMBLY64: call i64 @llvm.wasm.memory.grow.i64(i32 0, i64 %{{.*}})
 }
 
-__SIZE_TYPE__ tls_size() {
-  return __builtin_wasm_tls_size();
-  // WEBASSEMBLY32: call i32 @llvm.wasm.tls.size.i32()
-  // WEBASSEMBLY64: call i64 @llvm.wasm.tls.size.i64()
-}
-
-__SIZE_TYPE__ tls_align() {
-  return __builtin_wasm_tls_align();
-  // WEBASSEMBLY32: call i32 @llvm.wasm.tls.align.i32()
-  // WEBASSEMBLY64: call i64 @llvm.wasm.tls.align.i64()
-}
-
-void *tls_base() {
-  return __builtin_wasm_tls_base();
-  // WEBASSEMBLY: call i8* @llvm.wasm.tls.base()
-}
-
 void throw(void *obj) {
   return __builtin_wasm_throw(0, obj);
   // WEBASSEMBLY32: call void @llvm.wasm.throw(i32 0, i8* %{{.*}})
   // WEBASSEMBLY64: call void @llvm.wasm.throw(i32 0, i8* %{{.*}})
 }
 
 void rethrow_in_catch(void) {
   return __builtin_wasm_rethrow_in_catch();

llvm/include/llvm/IR/IntrinsicsWebAssembly.td

 
 // TODO: Remove this intrinsic and the associated builtin if i64x2.eq gets
 // merged to the proposal.
 def int_wasm_eq :
   Intrinsic<[llvm_v2i64_ty],
             [llvm_v2i64_ty, llvm_v2i64_ty],
             [IntrNoMem, IntrSpeculatable]>;
 
-//===----------------------------------------------------------------------===//
-// Thread-local storage intrinsics
-//===----------------------------------------------------------------------===//
-
-def int_wasm_tls_size :
-  Intrinsic<[llvm_anyint_ty],
-            [],
-            [IntrNoMem, IntrSpeculatable]>;
-
-def int_wasm_tls_align :
-  Intrinsic<[llvm_anyint_ty],
-            [],
-            [IntrNoMem, IntrSpeculatable]>;
-
-def int_wasm_tls_base :
-  Intrinsic<[llvm_ptr_ty],
-            [],
-            [IntrReadMem]>;
-
 } // TargetPrefix = "wasm"

llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp

case ISD::GlobalTLSAddress: {
     MachineSDNode *TLSOffset =
         CurDAG->getMachineNode(ConstIns, DL, PtrVT, TLSOffsetSym);
     MachineSDNode *TLSAddress = CurDAG->getMachineNode(
         AddIns, DL, PtrVT, SDValue(TLSBase, 0), SDValue(TLSOffset, 0));
     ReplaceNode(Node, TLSAddress);
     return;
   }
 
-  case ISD::INTRINSIC_WO_CHAIN: {
-    unsigned IntNo = cast<ConstantSDNode>(Node->getOperand(0))->getZExtValue();
-    switch (IntNo) {
-    case Intrinsic::wasm_tls_size: {
-      MachineSDNode *TLSSize = CurDAG->getMachineNode(
-          GlobalGetIns, DL, PtrVT,
-          CurDAG->getTargetExternalSymbol("__tls_size", PtrVT));
-      ReplaceNode(Node, TLSSize);
-      return;
-    }
-    case Intrinsic::wasm_tls_align: {
-      MachineSDNode *TLSAlign = CurDAG->getMachineNode(
-          GlobalGetIns, DL, PtrVT,
-          CurDAG->getTargetExternalSymbol("__tls_align", PtrVT));
-      ReplaceNode(Node, TLSAlign);
-      return;
-    }
-    }
-    break;
-  }
-  case ISD::INTRINSIC_W_CHAIN: {
-    unsigned IntNo = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
-    switch (IntNo) {
-    case Intrinsic::wasm_tls_base: {
-      MachineSDNode *TLSBase = CurDAG->getMachineNode(
-          GlobalGetIns, DL, PtrVT, MVT::Other,
-          CurDAG->getTargetExternalSymbol("__tls_base", PtrVT),
-          Node->getOperand(0));
-      ReplaceNode(Node, TLSBase);
-      return;
-    }
-    }
-    break;
-  }
   case WebAssemblyISD::CALL:
   case WebAssemblyISD::RET_CALL: {
     // CALL has both variable operands and variable results, but ISel only
     // supports one or the other. Split calls into two nodes glued together, one
     // for the operands and one for the results. These two nodes will be
     // recombined in a custom inserter hook into a single MachineInstr.
     SmallVector<SDValue, 16> Ops;
     for (size_t i = 1; i < Node->getNumOperands(); ++i) {

llvm/test/CodeGen/WebAssembly/tls-general-dynamic.ll

define void @tls_store(i32 %x) {
 
   ; NO-TLS-NEXT: i32.const 0
   ; NO-TLS-NEXT: i32.store tls
   ; NO-TLS-NEXT: return
   store i32 %x, i32* @tls, align 4
   ret void
 }
 
-; CHECK-LABEL: tls_size:
-; CHECK-NEXT: .functype tls_size () -> (i32)
-define i32 @tls_size() {
-; CHECK-NEXT: global.get __tls_size
-; CHECK-NEXT: return
-  %1 = call i32 @llvm.wasm.tls.size.i32()
-  ret i32 %1
-}
-
-; CHECK-LABEL: tls_align:
-; CHECK-NEXT: .functype tls_align () -> (i32)
-define i32 @tls_align() {
-; CHECK-NEXT: global.get __tls_align
-; CHECK-NEXT: return
-  %1 = call i32 @llvm.wasm.tls.align.i32()
-  ret i32 %1
-}
-
-; CHECK-LABEL: tls_base:
-; CHECK-NEXT: .functype tls_base () -> (i32)
-define i8* @tls_base() {
-; CHECK-NEXT: global.get __tls_base
-; CHECK-NEXT: return
-  %1 = call i8* @llvm.wasm.tls.base()
-  ret i8* %1
-}
-
-; CHECK-LABEL: tls_base_write:
-; CHECK-NEXT: .functype tls_base_write (i32) -> ()
-define void @tls_base_write(i8** %output) {
-; CHECK-NEXT: global.get __tls_base
-; CHECK-NEXT: i32.store 0
-; CHECK-NEXT: return
-  %1 = call i8* @llvm.wasm.tls.base()
-  store i8* %1, i8** %output
-  ret void
-}
-
 ; CHECK: .type tls,@object
 ; TLS-NEXT: .section .tbss.tls,"",@
 ; NO-TLS-NEXT: .section .bss.tls,"",@
 ; CHECK-NEXT: .p2align 2
 ; CHECK-NEXT: tls:
 ; CHECK-NEXT: .int32 0
 @tls = internal thread_local global i32 0
-
-declare i32 @llvm.wasm.tls.size.i32()
-declare i32 @llvm.wasm.tls.align.i32()
-declare i8* @llvm.wasm.tls.base()

llvm/test/CodeGen/WebAssembly/tls-local-exec.ll

define void @tls_store(i32 %x) {
 
   ; NO-TLS-NEXT: i32.const 0
   ; NO-TLS-NEXT: i32.store tls
   ; NO-TLS-NEXT: return
   store i32 %x, i32* @tls, align 4
   ret void
 }
 
-; CHECK-LABEL: tls_size:
-; CHECK-NEXT: .functype tls_size () -> (i32)
-define i32 @tls_size() {
-; CHECK-NEXT: global.get __tls_size
-; CHECK-NEXT: return
-  %1 = call i32 @llvm.wasm.tls.size.i32()
-  ret i32 %1
-}
-
 ; CHECK: .type tls,@object
 ; TLS-NEXT: .section .tbss.tls,"",@
 ; NO-TLS-NEXT: .section .bss.tls,"",@
 ; CHECK-NEXT: .p2align 2
 ; CHECK-NEXT: tls:
 ; CHECK-NEXT: .int32 0
 @tls = internal thread_local(localexec) global i32 0
-
-declare i32 @llvm.wasm.tls.size.i32()