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support inline assembly expressions with return type

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This commit is contained in:
Andrew Kelley 2015-12-15 00:46:56 -07:00
parent 66ca916805
commit a292eb8d64
6 changed files with 64 additions and 27 deletions
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2
doc/langref.md
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@ -84,7 +84,7 @@ AsmOutput : token(Colon) list(AsmOutputItem, token(Comma)) option(AsmInput)
AsmInput : token(Colon) list(AsmInputItem, token(Comma)) option(AsmClobbers)
AsmOutputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) token(Symbol) token(RParen)
AsmOutputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) (token(Symbol) | token(Return) Type) token(RParen)
AsmInputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) Expression token(RParen)

15
src/analyze.cpp
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@ -1233,16 +1233,27 @@ static TypeTableEntry * analyze_expression(CodeGen *g, ImportTableEntry *import,
}
case NodeTypeAsmExpr:
{
node->data.asm_expr.return_count = 0;
return_type = g->builtin_types.entry_void;
for (int i = 0; i < node->data.asm_expr.output_list.length; i += 1) {
AsmOutput *asm_output = node->data.asm_expr.output_list.at(i);
analyze_variable_name(g, import, context, node, &asm_output->variable_name);
if (asm_output->return_type) {
node->data.asm_expr.return_count += 1;
return_type = resolve_type(g, asm_output->return_type);
if (node->data.asm_expr.return_count > 1) {
add_node_error(g, node,
buf_sprintf("inline assembly allows up to one output value"));
break;
}
} else {
analyze_variable_name(g, import, context, node, &asm_output->variable_name);
}
}
for (int i = 0; i < node->data.asm_expr.input_list.length; i += 1) {
AsmInput *asm_input = node->data.asm_expr.input_list.at(i);
analyze_expression(g, import, context, nullptr, asm_input->expr);
}
return_type = g->builtin_types.entry_void;
break;
}
case NodeTypeBinOpExpr:

42
src/codegen.cpp
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@ -790,33 +790,45 @@ static LLVMValueRef gen_asm_expr(CodeGen *g, AstNode *node) {
Buf constraint_buf = BUF_INIT;
buf_resize(&constraint_buf, 0);
assert(asm_expr->return_count == 0 || asm_expr->return_count == 1);
int total_constraint_count = asm_expr->output_list.length +
asm_expr->input_list.length +
asm_expr->clobber_list.length;
int input_and_output_count = asm_expr->output_list.length +
asm_expr->input_list.length;
asm_expr->input_list.length -
asm_expr->return_count;
int total_index = 0;
int param_index = 0;
LLVMTypeRef *param_types = allocate<LLVMTypeRef>(input_and_output_count);
LLVMValueRef *param_values = allocate<LLVMValueRef>(input_and_output_count);
for (int i = 0; i < asm_expr->output_list.length; i += 1, total_index += 1) {
AsmOutput *asm_output = asm_expr->output_list.at(i);
bool is_return = false;
if (buf_eql_str(&asm_output->constraint, "=m")) {
buf_append_str(&constraint_buf, "=*m");
} else if (buf_eql_str(&asm_output->constraint, "=r")) {
buf_append_str(&constraint_buf, "=r");
is_return = true;
} else {
zig_panic("TODO unable to handle anything other than '=m' for outputs");
zig_panic("TODO unable to handle anything other than '=m' and '=r' for outputs");
}
if (total_index + 1 < total_constraint_count) {
buf_append_char(&constraint_buf, ',');
}
VariableTableEntry *variable = find_variable(
node->codegen_node->expr_node.block_context,
&asm_output->variable_name);
assert(variable);
param_types[total_index] = LLVMTypeOf(variable->value_ref);
param_values[total_index] = variable->value_ref;
if (!is_return) {
VariableTableEntry *variable = find_variable(
node->codegen_node->expr_node.block_context,
&asm_output->variable_name);
assert(variable);
param_types[param_index] = LLVMTypeOf(variable->value_ref);
param_values[param_index] = variable->value_ref;
param_index += 1;
}
}
for (int i = 0; i < asm_expr->input_list.length; i += 1, total_index += 1) {
for (int i = 0; i < asm_expr->input_list.length; i += 1, total_index += 1, param_index += 1) {
AsmInput *asm_input = asm_expr->input_list.at(i);
buf_append_buf(&constraint_buf, &asm_input->constraint);
if (total_index + 1 < total_constraint_count) {
@ -824,8 +836,8 @@ static LLVMValueRef gen_asm_expr(CodeGen *g, AstNode *node) {
}
TypeTableEntry *expr_type = get_expr_type(asm_input->expr);
param_types[total_index] = expr_type->type_ref;
param_values[total_index] = gen_expr(g, asm_input->expr);
param_types[param_index] = expr_type->type_ref;
param_values[param_index] = gen_expr(g, asm_input->expr);
}
for (int i = 0; i < asm_expr->clobber_list.length; i += 1, total_index += 1) {
Buf *clobber_buf = asm_expr->clobber_list.at(i);
@ -835,7 +847,13 @@ static LLVMValueRef gen_asm_expr(CodeGen *g, AstNode *node) {
}
}
LLVMTypeRef function_type = LLVMFunctionType(LLVMVoidType(), param_types, input_and_output_count, false);
LLVMTypeRef ret_type;
if (asm_expr->return_count == 0) {
ret_type = LLVMVoidType();
} else {
ret_type = get_expr_type(node)->type_ref;
}
LLVMTypeRef function_type = LLVMFunctionType(ret_type, param_types, input_and_output_count, false);
bool is_volatile = asm_expr->is_volatile || (asm_expr->output_list.length == 0);
LLVMValueRef asm_fn = LLVMConstInlineAsm(function_type, buf_ptr(&llvm_template),

18
src/parser.cpp
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@ -1731,7 +1731,7 @@ static void ast_parse_asm_input_item(ParseContext *pc, int *token_index, AstNode
}
/*
AsmOutputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) token(Symbol) token(RParen)
AsmOutputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) (token(Symbol) | token(Return) Type) token(RParen)
*/
static void ast_parse_asm_output_item(ParseContext *pc, int *token_index, AstNode *node) {
ast_eat_token(pc, token_index, TokenIdLBracket);
@ -1740,14 +1740,24 @@ static void ast_parse_asm_output_item(ParseContext *pc, int *token_index, AstNod
Token *constraint = ast_eat_token(pc, token_index, TokenIdStringLiteral);
AsmOutput *asm_output = allocate<AsmOutput>(1);
ast_eat_token(pc, token_index, TokenIdLParen);
Token *out_symbol = ast_eat_token(pc, token_index, TokenIdSymbol);
Token *token = &pc->tokens->at(*token_index);
*token_index += 1;
if (token->id == TokenIdSymbol) {
ast_buf_from_token(pc, token, &asm_output->variable_name);
} else if (token->id == TokenIdKeywordReturn) {
asm_output->return_type = ast_parse_type(pc, token_index);
} else {
ast_invalid_token_error(pc, token);
}
ast_eat_token(pc, token_index, TokenIdRParen);
AsmOutput *asm_output = allocate<AsmOutput>(1);
ast_buf_from_token(pc, alias, &asm_output->asm_symbolic_name);
parse_string_literal(pc, constraint, &asm_output->constraint, nullptr, nullptr);
ast_buf_from_token(pc, out_symbol, &asm_output->variable_name);
node->data.asm_expr.output_list.append(asm_output);
}

2
src/parser.hpp
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@ -228,6 +228,7 @@ struct AsmOutput {
Buf asm_symbolic_name;
Buf constraint;
Buf variable_name;
AstNode *return_type; // null unless "=r" and return
};
struct AsmInput {
@ -249,6 +250,7 @@ struct AstNodeAsmExpr {
ZigList<AsmOutput*> output_list;
ZigList<AsmInput*> input_list;
ZigList<Buf*> clobber_list;
int return_count; // populated by analyze
};
struct AstNodeStructDecl {

12
std/std.zig
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@ -3,20 +3,17 @@ const SYS_exit : isize = 60;
const stdout_fileno : isize = 1;
fn syscall1(number: isize, arg1: isize) -> isize {
var result : isize;
asm volatile ("
mov %[number], %%rax
mov %[arg1], %%rdi
syscall
mov %%rax, %[ret]"
: [ret] "=m" (result)
: [ret] "=r" (return isize)
: [number] "r" (number), [arg1] "r" (arg1)
: "rcx", "r11", "rax", "rdi");
return result;
: "rcx", "r11", "rax", "rdi")
}
fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {
var result : isize;
asm volatile ("
mov %[number], %%rax
mov %[arg1], %%rdi
@ -24,10 +21,9 @@ fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {
mov %[arg3], %%rdx
syscall
mov %%rax, %[ret]"
: [ret] "=m" (result)
: [ret] "=r" (return isize)
: [number] "r" (number), [arg1] "r" (arg1), [arg2] "r" (arg2), [arg3] "r" (arg3)
: "rcx", "r11", "rax", "rdi", "rsi", "rdx");
return result;
: "rcx", "r11", "rax", "rdi", "rsi", "rdx")
}
pub fn write(fd: isize, buf: &const u8, count: usize) -> isize {