stage2: cleanups to wasm memory intrinsics

 * AIR: use pl_op instead of ty_pl for wasm_memory_size. No need to
   store the type because the type is always `u32`.
 * AstGen: use coerced_ty for `@wasmMemorySize` and `@wasmMemoryGrow`
   and do the coercions in Sema.
 * Sema: use more accurate source locations for errors.
 * Provide more information in the compiler error message.
 * Codegen: use liveness data to avoid lowering unused
   `@wasmMemorySize`.
 * LLVM backend: add implementation
   - I wasn't able to test it because we are hitting a linker error for
     `-target wasm32-wasi -fLLVM`.
 * C backend: use `zig_unimplemented()` instead of silently doing wrong
   behavior for these builtins.
 * behavior tests: branch only on stage2_arch for inclusion of the
   wasm.zig file. We would change it to `builtin.cpu.arch` but that is
   causing a compiler crash on some backends.

1 files changed, 18 insertions, 4 deletions

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index bf754c975b..368a67f4b4 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -3478,13 +3478,27 @@ pub const FuncGen = struct {
     }
 
     fn airWasmMemorySize(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value {
-        _ = inst;
-        return self.todo("implement builtin `@wasmMemorySize()`", .{});
+        if (self.liveness.isUnused(inst)) return null;
+
+        const pl_op = self.air.instructions.items(.data)[inst].pl_op;
+        const index = pl_op.payload;
+        const llvm_u32 = self.context.intType(32);
+        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.size.i32", &.{llvm_u32});
+        const args: [1]*const llvm.Value = .{llvm_u32.constInt(index, .False)};
+        return self.builder.buildCall(llvm_fn, &args, args.len, .Fast, .Auto, "");
     }
 
     fn airWasmMemoryGrow(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value {
-        _ = inst;
-        return self.todo("implement builtin `@wasmMemoryGrow()`", .{});
+        const pl_op = self.air.instructions.items(.data)[inst].pl_op;
+        const index = pl_op.payload;
+        const operand = try self.resolveInst(pl_op.operand);
+        const llvm_u32 = self.context.intType(32);
+        const llvm_fn = self.getIntrinsic("llvm.wasm.memory.grow.i32", &.{ llvm_u32, llvm_u32 });
+        const args: [2]*const llvm.Value = .{
+            llvm_u32.constInt(index, .False),
+            operand,
+        };
+        return self.builder.buildCall(llvm_fn, &args, args.len, .Fast, .Auto, "");
     }
 
     fn airMin(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value {