Refactor prologue_epilogue. Break out into functions. Remove Vecs.

This commit is contained in:
Tyler McMullen
2017-12-03 23:25:32 -08:00
committed by Jakob Stoklund Olesen
parent c78a191294
commit c156eb9ff7
2 changed files with 74 additions and 93 deletions

View File

@@ -154,10 +154,10 @@ pub fn allocatable_registers(
regs
}
pub fn callee_saved_registers(flags: &shared_settings::Flags) -> Vec<RU> {
pub fn callee_saved_registers(flags: &shared_settings::Flags) -> &'static [RU] {
if flags.is_64bit() {
return vec![RU::rbx, RU::r12, RU::r13, RU::r14, RU::r15];
&[RU::rbx, RU::r12, RU::r13, RU::r14, RU::r15]
} else {
return vec![RU::rbx, RU::rsi, RU::rdi];
&[RU::rbx, RU::rsi, RU::rdi]
}
}

View File

@@ -127,129 +127,110 @@ impl TargetIsa for Isa {
ir::types::I32
};
let csrs = abi::callee_saved_registers(&self.shared_flags);
let csr_stack_size = ((csrs.len() + 1) * word_size as usize) as i32;
let mut csr_stack_size = word_size; // Size of RBP to start with
for _reg in &csrs {
csr_stack_size += word_size;
}
let stack_offset = -(csr_stack_size as i32);
let slot = ir::StackSlotData {
func.create_stack_slot(ir::StackSlotData {
kind: ir::StackSlotKind::IncomingArg,
size: csr_stack_size,
offset: stack_offset,
};
func.create_stack_slot(slot);
size: csr_stack_size as u32,
offset: -csr_stack_size,
});
let total_stack_size = layout_stack(&mut func.stack_slots, word_size)?;
let total_stack_size = layout_stack(&mut func.stack_slots, word_size)? as i32;
let local_stack_size = (total_stack_size - csr_stack_size) as i64;
// Build up list of args, which we'll append forwards to the params and
// backwards to the returns.
let mut csr_args = Vec::new();
csr_args.push(ir::AbiParam::special_reg(
// Add CSRs to function signature
let fp_arg = ir::AbiParam::special_reg(
csr_type,
ir::ArgumentPurpose::FramePointer,
RU::rbp as RegUnit,
));
for reg in &csrs {
csr_args.push(ir::AbiParam::special_reg(
);
func.signature.params.push(fp_arg);
func.signature.returns.push(fp_arg);
for csr in csrs.iter() {
let csr_arg = ir::AbiParam::special_reg(
csr_type,
ir::ArgumentPurpose::CalleeSaved,
*reg as RegUnit,
));
}
for csr_arg in &csr_args {
func.signature.params.push(*csr_arg);
}
for csr_arg in csr_args.iter().rev() {
func.signature.returns.push(*csr_arg);
}
// Append param to entry EBB
let entry_ebb = func.layout.entry_block().expect("missing entry block");
let fp = func.dfg.append_ebb_param(entry_ebb, csr_type);
// Assign it a location
func.locations[fp] = ir::ValueLoc::Reg(RU::rbp as RegUnit);
let mut csr_vals = Vec::new();
for reg in &csrs {
// Append param to entry EBB
let csr_arg = func.dfg.append_ebb_param(entry_ebb, csr_type);
// Assign it a location
func.locations[csr_arg] = ir::ValueLoc::Reg(*reg as RegUnit);
// Remember it so we can push it momentarily
csr_vals.push(csr_arg);
}
// Insert prologue
{
let mut pos = EncCursor::new(func, self).at_first_insertion_point(entry_ebb);
pos.ins().x86_push(fp);
pos.ins().copy_special(
RU::rsp as RegUnit,
RU::rbp as RegUnit,
*csr as RegUnit,
);
if local_stack_size > 0 {
pos.ins().adjust_sp_imm(Imm64::new(-local_stack_size));
}
for csr_arg in csr_vals {
pos.ins().x86_push(csr_arg);
}
func.signature.params.push(csr_arg);
func.signature.returns.push(csr_arg);
}
// Find all 'return' instructions
let mut return_insts = Vec::new();
for ebb in func.layout.ebbs() {
if let Some(inst) = func.layout.last_inst(ebb) {
if func.dfg[inst].opcode().is_return() {
return_insts.push(inst);
}
}
}
// Insert an epilogue directly before every 'return'
for inst in return_insts {
self.insert_epilogue(inst, local_stack_size, func, &csrs, csr_type);
}
let entry_ebb = func.layout.entry_block().expect("missing entry block");
let mut pos = EncCursor::new(func, self).at_first_insertion_point(entry_ebb);
self.insert_prologue(&mut pos, local_stack_size, csr_type);
self.insert_epilogues(&mut pos, local_stack_size, csr_type);
Ok(())
}
}
impl Isa {
fn insert_prologue(&self, pos: &mut EncCursor, stack_size: i64, csr_type: ir::types::Type) {
// Append param to entry EBB
let ebb = pos.current_ebb().expect("missing ebb under cursor");
let fp = pos.func.dfg.append_ebb_param(ebb, csr_type);
pos.func.locations[fp] = ir::ValueLoc::Reg(RU::rbp as RegUnit);
pos.ins().x86_push(fp);
pos.ins().copy_special(
RU::rsp as RegUnit,
RU::rbp as RegUnit,
);
if stack_size > 0 {
pos.ins().adjust_sp_imm(Imm64::new(-stack_size));
}
let csrs = abi::callee_saved_registers(&self.shared_flags);
for reg in csrs.iter() {
// Append param to entry EBB
let csr_arg = pos.func.dfg.append_ebb_param(ebb, csr_type);
// Assign it a location
pos.func.locations[csr_arg] = ir::ValueLoc::Reg(*reg as RegUnit);
// Remember it so we can push it momentarily
pos.ins().x86_push(csr_arg);
}
}
fn insert_epilogues(&self, pos: &mut EncCursor, stack_size: i64, csr_type: ir::types::Type) {
while let Some(ebb) = pos.next_ebb() {
pos.goto_last_inst(ebb);
if let Some(inst) = pos.current_inst() {
if pos.func.dfg[inst].opcode().is_return() {
self.insert_epilogue(inst, stack_size, pos, csr_type);
}
}
}
}
fn insert_epilogue(
&self,
inst: ir::Inst,
stack_size: i64,
func: &mut ir::Function,
csrs: &Vec<RU>,
pos: &mut EncCursor,
csr_type: ir::types::Type,
) {
let mut return_values = Vec::new();
let mut pos = EncCursor::new(func, self).at_inst(inst);
if stack_size > 0 {
pos.ins().adjust_sp_imm(Imm64::new(stack_size));
}
let csrs = abi::callee_saved_registers(&self.shared_flags);
for reg in csrs.iter().rev() {
let csr_ret = pos.ins().x86_pop(csr_type);
return_values.push((csr_ret, *reg));
pos.func.locations[csr_ret] = ir::ValueLoc::Reg(*reg as RegUnit);
pos.func.dfg.append_inst_arg(inst, csr_ret);
}
let fp_ret = pos.ins().x86_pop(csr_type);
return_values.push((fp_ret, RU::rbp));
let func = pos.func;
for (val, reg) in return_values {
func.locations[val] = ir::ValueLoc::Reg(reg as RegUnit);
func.dfg.append_inst_arg(inst, val);
}
let fp_ret = pos.ins().x86_pop(csr_type);
pos.func.locations[fp_ret] = ir::ValueLoc::Reg(RU::rbp as RegUnit);
pos.func.dfg.append_inst_arg(inst, fp_ret);
}
}