| #[cfg(test)] |
| use stdarch_test::assert_instr; |
| |
| extern "C" { |
| #[link_name = "llvm.wasm.memory.grow"] |
| fn llvm_memory_grow(mem: u32, pages: usize) -> usize; |
| #[link_name = "llvm.wasm.memory.size"] |
| fn llvm_memory_size(mem: u32) -> usize; |
| } |
| |
| /// Corresponding intrinsic to wasm's [`memory.size` instruction][instr] |
| /// |
| /// This function, when called, will return the current memory size in units of |
| /// pages. The current WebAssembly page size is 65536 bytes (64 KB). |
| /// |
| /// The argument `MEM` is the numerical index of which memory to return the |
| /// size of. Note that currently the WebAssembly specification only supports one |
| /// memory, so it is required that zero is passed in. The argument is present to |
| /// be forward-compatible with future WebAssembly revisions. If a nonzero |
| /// argument is passed to this function it will currently unconditionally abort. |
| /// |
| /// [instr]: http://webassembly.github.io/spec/core/exec/instructions.html#exec-memory-size |
| #[inline] |
| #[cfg_attr(test, assert_instr("memory.size", MEM = 0))] |
| #[rustc_legacy_const_generics(0)] |
| #[stable(feature = "simd_wasm32", since = "1.33.0")] |
| #[doc(alias("memory.size"))] |
| pub fn memory_size<const MEM: u32>() -> usize { |
| static_assert!(MEM: u32 where MEM == 0); |
| unsafe { llvm_memory_size(MEM) } |
| } |
| |
| /// Corresponding intrinsic to wasm's [`memory.grow` instruction][instr] |
| /// |
| /// This function, when called, will attempt to grow the default linear memory |
| /// by the specified `delta` of pages. The current WebAssembly page size is |
| /// 65536 bytes (64 KB). If memory is successfully grown then the previous size |
| /// of memory, in pages, is returned. If memory cannot be grown then |
| /// `usize::MAX` is returned. |
| /// |
| /// The argument `MEM` is the numerical index of which memory to return the |
| /// size of. Note that currently the WebAssembly specification only supports one |
| /// memory, so it is required that zero is passed in. The argument is present to |
| /// be forward-compatible with future WebAssembly revisions. If a nonzero |
| /// argument is passed to this function it will currently unconditionally abort. |
| /// |
| /// [instr]: http://webassembly.github.io/spec/core/exec/instructions.html#exec-memory-grow |
| #[inline] |
| #[cfg_attr(test, assert_instr("memory.grow", MEM = 0))] |
| #[rustc_legacy_const_generics(0)] |
| #[stable(feature = "simd_wasm32", since = "1.33.0")] |
| #[doc(alias("memory.grow"))] |
| pub fn memory_grow<const MEM: u32>(delta: usize) -> usize { |
| unsafe { |
| static_assert!(MEM: u32 where MEM == 0); |
| llvm_memory_grow(MEM, delta) |
| } |
| } |