mirror-llvm-project/llvm/test/CodeGen/WebAssembly/funcref-tableset.ll
Hood Chatham 765f0d14fe
[WebAssembly] Represent reference types as TargetExtType (#203165)
Originally #71540 by Paolo Matos, I picked it up and finished it.
Resolves https://github.com/llvm/llvm-project/issues/69894.

Model WebAssembly externref and funcref as target("wasm.externref") /
target("wasm.funcref") TargetExtTypes instead of pointers in
non-integral address spaces 10 and 20.

The entire WebAssemblyLowerRefTypesIntPtrConv can be removed.

This breaks the GlobalISel handling for reference types, I just disabled
GlobalISel handling for functions that use them.

I added intrinsics for `wasm.ptr.to_funcref` and `wasm.funcref.to_ptr`.
ptr.to_funcref does a table.get from the indirect function pointer
table. As a special case, 0 is converted to the null funcref rather than
doing table.get on 0. `wasm.funcref.to_ptr` is only handled when we call
it immediately, otherwise it will fail to lower. We could dynamically
put the funcref into the table to make it work but that would require a
stack of spilled funcrefs and isn't worth the effort.

In the process of looking into this, I noticed that clang used to allow
casting from funcref to function pointer but if the cast result escaped
it would hit `Cannot select: FUNCREF_TO_PTR` in the backend. I added a
diagnostic that says "a funcref can only be converted to a pointer to be
directly called" to make this a little cleaner.

cc @QuantumSegfault

---------

Co-authored-by: Paulo Matos <pmatos@igalia.com>
2026-06-24 22:07:33 -07:00

79 lines
2.9 KiB
LLVM

; RUN: llc --mtriple=wasm32-unknown-unknown -asm-verbose=false -mattr=+reference-types < %s | FileCheck %s
%funcref = type target("wasm.funcref")
@funcref_table = local_unnamed_addr addrspace(1) global [0 x %funcref] undef
declare void @llvm.wasm.table.set.funcref(ptr addrspace(1), i32, %funcref) nounwind
define void @set_funcref_table(%funcref %g, i32 %i) {
; CHECK-LABEL: set_funcref_table:
; CHECK-NEXT: .functype set_funcref_table (funcref, i32) -> ()
; CHECK-NEXT: local.get 1
; CHECK-NEXT: local.get 0
; CHECK-NEXT: table.set funcref_table
; CHECK-NEXT: end_function
;; this generates a table.set of @funcref_table
call void @llvm.wasm.table.set.funcref(ptr addrspace(1) @funcref_table, i32 %i, %funcref %g)
ret void
}
define void @set_funcref_table_const(%funcref %g) {
; CHECK-LABEL: set_funcref_table_const:
; CHECK-NEXT: .functype set_funcref_table_const (funcref) -> ()
; CHECK-NEXT: i32.const 0
; CHECK-NEXT: local.get 0
; CHECK-NEXT: table.set funcref_table
; CHECK-NEXT: end_function
call void @llvm.wasm.table.set.funcref(ptr addrspace(1) @funcref_table, i32 0, %funcref %g)
ret void
}
define void @set_funcref_table_with_offset(%funcref %g, i32 %i) {
; CHECK-LABEL: set_funcref_table_with_offset:
; CHECK-NEXT: .functype set_funcref_table_with_offset (funcref, i32) -> ()
; CHECK-NEXT: local.get 1
; CHECK-NEXT: i32.const 2
; CHECK-NEXT: i32.add
; CHECK-NEXT: local.get 0
; CHECK-NEXT: table.set funcref_table
; CHECK-NEXT: end_function
%off = add nsw i32 %i, 2
call void @llvm.wasm.table.set.funcref(ptr addrspace(1) @funcref_table, i32 %off, %funcref %g)
ret void
}
define void @set_funcref_table_with_var_offset(%funcref %g, i32 %i, i32 %j) {
; CHECK-LABEL: set_funcref_table_with_var_offset:
; CHECK-NEXT: .functype set_funcref_table_with_var_offset (funcref, i32, i32) -> ()
; CHECK-NEXT: local.get 1
; CHECK-NEXT: local.get 2
; CHECK-NEXT: i32.add
; CHECK-NEXT: local.get 0
; CHECK-NEXT: table.set funcref_table
; CHECK-NEXT: end_function
%off = add nsw i32 %i, %j
call void @llvm.wasm.table.set.funcref(ptr addrspace(1) @funcref_table, i32 %off, %funcref %g)
ret void
}
declare i32 @set_offset()
define void @set_funcref_table_with_var_offset2(%funcref %g, i32 %i) {
; CHECK-LABEL: set_funcref_table_with_var_offset2:
; CHECK-NEXT: .functype set_funcref_table_with_var_offset2 (funcref, i32) -> ()
; CHECK-NEXT: local.get 1
; CHECK-NEXT: call set_offset
; CHECK-NEXT: i32.add
; CHECK-NEXT: local.get 0
; CHECK-NEXT: table.set funcref_table
; CHECK-NEXT: end_function
%j = call i32 @set_offset()
%off = add nsw i32 %i, %j
call void @llvm.wasm.table.set.funcref(ptr addrspace(1) @funcref_table, i32 %off, %funcref %g)
ret void
}
; CHECK: .tabletype funcref_table, funcref
; CHECK-LABEL: funcref_table: