Add builtin for llvm.wasm.memory.grow.i32 intrinsic

This will allow the developer to request additional memory pages
from the runtime to be allocated for the Wasm app. Typical usage:

```zig
var wasm_pages = @wasmMemorySize();
@wasmMemoryGrow(1);
@import("std").debug.assert((wasm_pages + 1) == @wasmMemorySize());
```

src/all_types.hpp

@@ -1826,6 +1826,7 @@ enum BuiltinFnId {
     BuiltinFnIdCall,
     BuiltinFnIdBitSizeof,
     BuiltinFnIdWasmMemorySize,
+    BuiltinFnIdWasmMemoryGrow,
 };
 
 struct BuiltinFnEntry {
@@ -2077,6 +2078,7 @@ struct CodeGen {
     LLVMValueRef safety_crash_err_fn;
     LLVMValueRef return_err_fn;
     LLVMValueRef wasm_memory_size;
+    LLVMValueRef wasm_memory_grow;
     LLVMTypeRef anyframe_fn_type;
 
     // reminder: hash tables must be initialized before use
@@ -2751,6 +2753,7 @@ enum IrInstSrcId {
     IrInstSrcIdSpillBegin,
     IrInstSrcIdSpillEnd,
     IrInstSrcIdWasmMemorySize,
+    IrInstSrcIdWasmMemoryGrow,
 };
 
 // ir_render_* functions in codegen.cpp consume Gen instructions and produce LLVM IR.
@@ -2844,6 +2847,7 @@ enum IrInstGenId {
     IrInstGenIdAlloca,
     IrInstGenIdConst,
     IrInstGenIdWasmMemorySize,
+    IrInstGenIdWasmMemoryGrow,
 };
 
 // Common fields between IrInstSrc and IrInstGen. This allows future passes
@@ -3732,11 +3736,23 @@ struct IrInstGenMemcpy {
 };
 
 struct IrInstSrcWasmMemorySize {
-  IrInstSrc base;
+    IrInstSrc base;
 };
 
 struct IrInstGenWasmMemorySize {
-  IrInstGen base;
+    IrInstGen base;
+};
+
+struct IrInstSrcWasmMemoryGrow {
+    IrInstSrc base;
+
+    IrInstSrc *delta;
+};
+
+struct IrInstGenWasmMemoryGrow {
+    IrInstGen base;
+
+    IrInstGen *delta;
 };
 
 struct IrInstSrcSlice {

src/codegen.cpp

@@ -1047,8 +1047,9 @@ static void gen_assertion(CodeGen *g, PanicMsgId msg_id, IrInstGen *source_instr
 
 static LLVMValueRef gen_wasm_memory_size(CodeGen *g) {
     if (g->wasm_memory_size)
-      return g->wasm_memory_size;
+        return g->wasm_memory_size;
 
+    // TODO adjust for wasm64 as well
     // declare i32 @llvm.wasm.memory.size.i32(i32) nounwind readonly
     LLVMTypeRef param_type = LLVMInt32Type();
     LLVMTypeRef fn_type = LLVMFunctionType(LLVMInt32Type(), &param_type, 1, false);
@@ -1058,6 +1059,23 @@ static LLVMValueRef gen_wasm_memory_size(CodeGen *g) {
     return g->wasm_memory_size;
 }
 
+static LLVMValueRef gen_wasm_memory_grow(CodeGen *g) {
+    if (g->wasm_memory_grow)
+        return g->wasm_memory_grow;
+
+    // TODO adjust for wasm64 as well
+    // declare i32 @llvm.wasm.memory.grow.i32(i32, i32) nounwind
+    LLVMTypeRef param_types[] = {
+        LLVMInt32Type(),
+        LLVMInt32Type(),
+    };
+    LLVMTypeRef fn_type = LLVMFunctionType(LLVMInt32Type(), param_types, 2, false);
+    g->wasm_memory_grow = LLVMAddFunction(g->module, "llvm.wasm.memory.grow.i32", fn_type);
+    assert(LLVMGetIntrinsicID(g->wasm_memory_grow));
+
+    return g->wasm_memory_grow;
+}
+
 static LLVMValueRef get_stacksave_fn_val(CodeGen *g) {
     if (g->stacksave_fn_val)
         return g->stacksave_fn_val;
@@ -5607,11 +5625,27 @@ static LLVMValueRef ir_render_wasm_memory_size(CodeGen *g, IrExecutableGen *exec
     //
     // More info:
     // https://github.com/sunfishcode/wasm-reference-manual/blob/master/WebAssembly.md#current-linear-memory-size
+    // TODO adjust for wasm64
     LLVMValueRef zero = LLVMConstNull(g->builtin_types.entry_i32->llvm_type);
     LLVMValueRef val = LLVMBuildCall(g->builder, gen_wasm_memory_size(g), &zero, 1, "");
     return val;
 }
 
+static LLVMValueRef ir_render_wasm_memory_grow(CodeGen *g, IrExecutableGen *executable, IrInstGenWasmMemoryGrow *instruction) {
+    // When Wasm lands multi-memory support, we can relax this to permit the user specify
+    // memory index to inquire about. For now, we pass in the recommended default of index 0.
+    //
+    // More info:
+    // https://github.com/sunfishcode/wasm-reference-manual/blob/master/WebAssembly.md#grow-linear-memory-size
+    // TODO adjust for wasm64
+    LLVMValueRef params[] = {
+        LLVMConstNull(g->builtin_types.entry_i32->llvm_type),
+        ir_llvm_value(g, instruction->delta),
+    };
+    LLVMValueRef val = LLVMBuildCall(g->builder, gen_wasm_memory_grow(g), params, 2, "");
+    return val;
+}
+
 static LLVMValueRef ir_render_slice(CodeGen *g, IrExecutableGen *executable, IrInstGenSlice *instruction) {
     Error err;
 
@@ -6824,6 +6858,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutableGen *executabl
             return ir_render_vector_extract_elem(g, executable, (IrInstGenVectorExtractElem *) instruction);
         case IrInstGenIdWasmMemorySize:
             return ir_render_wasm_memory_size(g, executable, (IrInstGenWasmMemorySize *) instruction);
+        case IrInstGenIdWasmMemoryGrow:
+            return ir_render_wasm_memory_grow(g, executable, (IrInstGenWasmMemoryGrow *) instruction);
     }
     zig_unreachable();
 }
@@ -8687,6 +8723,7 @@ static void define_builtin_fns(CodeGen *g) {
     create_builtin_fn(g, BuiltinFnIdCall, "call", 3);
     create_builtin_fn(g, BuiltinFnIdBitSizeof, "bitSizeOf", 1);
     create_builtin_fn(g, BuiltinFnIdWasmMemorySize, "wasmMemorySize", 0);
+    create_builtin_fn(g, BuiltinFnIdWasmMemoryGrow, "wasmMemoryGrow", 1);
 }
 
 static const char *bool_to_str(bool b) {

src/ir.cpp

@@ -558,6 +558,8 @@ static void destroy_instruction_src(IrInstSrc *inst) {
             return heap::c_allocator.destroy(reinterpret_cast<IrInstSrcCallArgs *>(inst));
         case IrInstSrcIdWasmMemorySize:
             return heap::c_allocator.destroy(reinterpret_cast<IrInstSrcWasmMemorySize *>(inst));
+        case IrInstSrcIdWasmMemoryGrow:
+            return heap::c_allocator.destroy(reinterpret_cast<IrInstSrcWasmMemoryGrow *>(inst));
     }
     zig_unreachable();
 }
@@ -740,6 +742,8 @@ void destroy_instruction_gen(IrInstGen *inst) {
             return heap::c_allocator.destroy(reinterpret_cast<IrInstGenNegationWrapping *>(inst));
         case IrInstGenIdWasmMemorySize:
             return heap::c_allocator.destroy(reinterpret_cast<IrInstGenWasmMemorySize *>(inst));
+        case IrInstGenIdWasmMemoryGrow:
+            return heap::c_allocator.destroy(reinterpret_cast<IrInstGenWasmMemoryGrow *>(inst));
     }
     zig_unreachable();
 }
@@ -1338,10 +1342,6 @@ static constexpr IrInstSrcId ir_inst_id(IrInstSrcBoolNot *) {
     return IrInstSrcIdBoolNot;
 }
 
-static constexpr IrInstSrcId ir_inst_id(IrInstSrcWasmMemorySize *) {
-    return IrInstSrcIdWasmMemorySize;
-}
-
 static constexpr IrInstSrcId ir_inst_id(IrInstSrcMemset *) {
     return IrInstSrcIdMemset;
 }
@@ -1618,6 +1618,14 @@ static constexpr IrInstSrcId ir_inst_id(IrInstSrcSpillEnd *) {
     return IrInstSrcIdSpillEnd;
 }
 
+static constexpr IrInstSrcId ir_inst_id(IrInstSrcWasmMemorySize *) {
+    return IrInstSrcIdWasmMemorySize;
+}
+
+static constexpr IrInstSrcId ir_inst_id(IrInstSrcWasmMemoryGrow *) {
+    return IrInstSrcIdWasmMemoryGrow;
+}
+
 
 static constexpr IrInstGenId ir_inst_id(IrInstGenDeclVar *) {
     return IrInstGenIdDeclVar;
@@ -1967,6 +1975,10 @@ static constexpr IrInstGenId ir_inst_id(IrInstGenWasmMemorySize *) {
   return IrInstGenIdWasmMemorySize;
 }
 
+static constexpr IrInstGenId ir_inst_id(IrInstGenWasmMemoryGrow *) {
+  return IrInstGenIdWasmMemoryGrow;
+}
+
 template<typename T>
 static T *ir_create_instruction(IrBuilderSrc *irb, Scope *scope, AstNode *source_node) {
     T *special_instruction = heap::c_allocator.create<T>();
@@ -3654,20 +3666,6 @@ static IrInstGen *ir_build_bool_not_gen(IrAnalyze *ira, IrInst *source_instr, Ir
     return &instruction->base;
 }
 
-static IrInstSrc *ir_build_wasm_memory_size_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node) {
-    IrInstSrcWasmMemorySize *instruction = ir_build_instruction<IrInstSrcWasmMemorySize>(irb, scope, source_node);
-
-    return &instruction->base;
-}
-
-static IrInstGen *ir_build_wasm_memory_size_gen(IrAnalyze *ira, IrInst *source_instr) {
-    IrInstGenWasmMemorySize *instruction = ir_build_inst_gen<IrInstGenWasmMemorySize>(&ira->new_irb,
-            source_instr->scope, source_instr->source_node);
-    instruction->base.value->type = ira->codegen->builtin_types.entry_i32;
-
-    return &instruction->base;
-}
-
 static IrInstSrc *ir_build_memset_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node,
     IrInstSrc *dest_ptr, IrInstSrc *byte, IrInstSrc *count)
 {
@@ -4987,6 +4985,41 @@ static IrInstGen *ir_build_vector_extract_elem(IrAnalyze *ira, IrInst *source_in
     return &instruction->base;
 }
 
+static IrInstSrc *ir_build_wasm_memory_size_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node) {
+    IrInstSrcWasmMemorySize *instruction = ir_build_instruction<IrInstSrcWasmMemorySize>(irb, scope, source_node);
+
+    return &instruction->base;
+}
+
+static IrInstGen *ir_build_wasm_memory_size_gen(IrAnalyze *ira, IrInst *source_instr) {
+    IrInstGenWasmMemorySize *instruction = ir_build_inst_gen<IrInstGenWasmMemorySize>(&ira->new_irb,
+            source_instr->scope, source_instr->source_node);
+    instruction->base.value->type = ira->codegen->builtin_types.entry_i32;
+
+    return &instruction->base;
+}
+
+static IrInstSrc *ir_build_wasm_memory_grow_src(IrBuilderSrc *irb, Scope *scope, AstNode *source_node, IrInstSrc *delta) {
+    IrInstSrcWasmMemoryGrow *instruction = ir_build_instruction<IrInstSrcWasmMemoryGrow>(irb, scope, source_node);
+    instruction->delta = delta;
+
+    ir_ref_instruction(delta, irb->current_basic_block);
+
+    return &instruction->base;
+}
+
+static IrInstGen *ir_build_wasm_memory_grow_gen(IrAnalyze *ira, IrInst *source_instr, IrInstGen *delta) {
+    IrInstGenWasmMemoryGrow *instruction = ir_build_inst_gen<IrInstGenWasmMemoryGrow>(&ira->new_irb,
+            source_instr->scope, source_instr->source_node);
+    instruction->base.value->type = ira->codegen->builtin_types.entry_i32;
+    instruction->delta = delta;
+
+    ir_ref_inst_gen(delta);
+
+    return &instruction->base;
+}
+
+
 static void ir_count_defers(IrBuilderSrc *irb, Scope *inner_scope, Scope *outer_scope, size_t *results) {
     results[ReturnKindUnconditional] = 0;
     results[ReturnKindError] = 0;
@@ -6785,6 +6818,16 @@ static IrInstSrc *ir_gen_builtin_fn_call(IrBuilderSrc *irb, Scope *scope, AstNod
                 IrInstSrc *ir_wasm_memory_size = ir_build_wasm_memory_size_src(irb, scope, node);
                 return ir_lval_wrap(irb, scope, ir_wasm_memory_size, lval, result_loc);
             }
+        case BuiltinFnIdWasmMemoryGrow:
+            {
+                AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
+                IrInstSrc *arg0_value = ir_gen_node(irb, arg0_node, scope);
+                if (arg0_value == irb->codegen->invalid_inst_src)
+                    return arg0_value;
+
+                IrInstSrc *ir_wasm_memory_grow = ir_build_wasm_memory_grow_src(irb, scope, node, arg0_value);
+                return ir_lval_wrap(irb, scope, ir_wasm_memory_grow, lval, result_loc);
+            }
         case BuiltinFnIdField:
             {
                 AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
@@ -27683,15 +27726,37 @@ static IrInstGen *ir_analyze_instruction_has_field(IrAnalyze *ira, IrInstSrcHasF
 }
 
 static IrInstGen *ir_analyze_instruction_wasm_memory_size(IrAnalyze *ira, IrInstSrcWasmMemorySize *instruction) {
+    // TODO generate compile error for target_arch different than 32bit
     if (!target_is_wasm(ira->codegen->zig_target)) {
         ir_add_error_node(ira, instruction->base.base.source_node,
-            buf_sprintf("@wasmMemorySize is a wasm feature only"));
+            buf_sprintf("@wasmMemorySize is a wasm32 feature only"));
         return ira->codegen->invalid_inst_gen;
     }
 
     return ir_build_wasm_memory_size_gen(ira, &instruction->base.base);
 }
 
+static IrInstGen *ir_analyze_instruction_wasm_memory_grow(IrAnalyze *ira, IrInstSrcWasmMemoryGrow *instruction) {
+    // TODO generate compile error for target_arch different than 32bit
+    if (!target_is_wasm(ira->codegen->zig_target)) {
+        ir_add_error_node(ira, instruction->base.base.source_node,
+            buf_sprintf("@wasmMemoryGrow is a wasm32 feature only"));
+        return ira->codegen->invalid_inst_gen;
+    }
+
+    IrInstGen *delta = instruction->delta->child;
+    if (type_is_invalid(delta->value->type))
+        return ira->codegen->invalid_inst_gen;
+
+    ZigType *i32_type = ira->codegen->builtin_types.entry_i32;
+
+    IrInstGen *casted_delta = ir_implicit_cast(ira, delta, i32_type);
+    if (type_is_invalid(casted_delta->value->type))
+        return ira->codegen->invalid_inst_gen;
+
+    return ir_build_wasm_memory_grow_gen(ira, &instruction->base.base, casted_delta);
+}
+
 static IrInstGen *ir_analyze_instruction_breakpoint(IrAnalyze *ira, IrInstSrcBreakpoint *instruction) {
     return ir_build_breakpoint_gen(ira, &instruction->base.base);
 }
@@ -30935,6 +31000,8 @@ static IrInstGen *ir_analyze_instruction_base(IrAnalyze *ira, IrInstSrc *instruc
             return ir_analyze_instruction_spill_end(ira, (IrInstSrcSpillEnd *)instruction);
         case IrInstSrcIdWasmMemorySize:
             return ir_analyze_instruction_wasm_memory_size(ira, (IrInstSrcWasmMemorySize *)instruction);
+        case IrInstSrcIdWasmMemoryGrow:
+            return ir_analyze_instruction_wasm_memory_grow(ira, (IrInstSrcWasmMemoryGrow *)instruction);
     }
     zig_unreachable();
 }
@@ -31111,6 +31178,7 @@ bool ir_inst_gen_has_side_effects(IrInstGen *instruction) {
         case IrInstGenIdResume:
         case IrInstGenIdAwait:
         case IrInstGenIdSpillBegin:
+        case IrInstGenIdWasmMemoryGrow:
             return true;
 
         case IrInstGenIdPhi:
@@ -31243,6 +31311,7 @@ bool ir_inst_src_has_side_effects(IrInstSrc *instruction) {
         case IrInstSrcIdResume:
         case IrInstSrcIdAwait:
         case IrInstSrcIdSpillBegin:
+        case IrInstSrcIdWasmMemoryGrow:
             return true;
 
         case IrInstSrcIdPhi:

src/ir_print.cpp

@@ -323,6 +323,8 @@ const char* ir_inst_src_type_str(IrInstSrcId id) {
             return "SrcSpillEnd";
         case IrInstSrcIdWasmMemorySize:
             return "SrcWasmMemorySize";
+        case IrInstSrcIdWasmMemoryGrow:
+            return "SrcWasmMemoryGrow";
     }
     zig_unreachable();
 }
@@ -505,6 +507,8 @@ const char* ir_inst_gen_type_str(IrInstGenId id) {
             return "GenNegationWrapping";
         case IrInstGenIdWasmMemorySize:
             return "GenWasmMemorySize";
+        case IrInstGenIdWasmMemoryGrow:
+            return "GenWasmMemoryGrow";
     }
     zig_unreachable();
 }
@@ -1720,6 +1724,18 @@ static void ir_print_wasm_memory_size(IrPrintGen *irp, IrInstGenWasmMemorySize *
     fprintf(irp->f, "@wasmMemorySize()");
 }
 
+static void ir_print_wasm_memory_grow(IrPrintSrc *irp, IrInstSrcWasmMemoryGrow *instruction) {
+    fprintf(irp->f, "@wasmMemoryGrow(");
+    ir_print_other_inst_src(irp, instruction->delta);
+    fprintf(irp->f, ")");
+}
+
+static void ir_print_wasm_memory_grow(IrPrintGen *irp, IrInstGenWasmMemoryGrow *instruction) {
+    fprintf(irp->f, "@wasmMemoryGrow(");
+    ir_print_other_inst_gen(irp, instruction->delta);
+    fprintf(irp->f, ")");
+}
+
 static void ir_print_memset(IrPrintSrc *irp, IrInstSrcMemset *instruction) {
     fprintf(irp->f, "@memset(");
     ir_print_other_inst_src(irp, instruction->dest_ptr);
@@ -2967,6 +2983,9 @@ static void ir_print_inst_src(IrPrintSrc *irp, IrInstSrc *instruction, bool trai
         case IrInstSrcIdWasmMemorySize:
             ir_print_wasm_memory_size(irp, (IrInstSrcWasmMemorySize *)instruction);
             break;
+        case IrInstSrcIdWasmMemoryGrow:
+            ir_print_wasm_memory_grow(irp, (IrInstSrcWasmMemoryGrow *)instruction);
+            break;
     }
     fprintf(irp->f, "\n");
 }
@@ -3237,6 +3256,9 @@ static void ir_print_inst_gen(IrPrintGen *irp, IrInstGen *instruction, bool trai
         case IrInstGenIdWasmMemorySize:
             ir_print_wasm_memory_size(irp, (IrInstGenWasmMemorySize *)instruction);
             break;
+        case IrInstGenIdWasmMemoryGrow:
+            ir_print_wasm_memory_grow(irp, (IrInstGenWasmMemoryGrow *)instruction);
+            break;
     }
     fprintf(irp->f, "\n");
 }