T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactor calling convention settings. (#304)

Browse Source 
Add a calling-convention setting to the `Flags` used as part of the
`TargetIsa`. This allows Cretonne code that generates calls to use the
correct convention, such as when emitting libcalls during legalization
or when the wasm frontend is decoding functions. This setting can be
overridden per-function.

This also adds "fast", "cold", and "fastcall" conventions, with "fast"
as the new default. Note that "fast" and "cold" are not intended to be
ABI-compatible across Cretonne versions.

This will also ensure Windows users will get an `unimplemented!` rather
than silent calling-convention mismatches, which reflects the fact that
Windows calling conventions are not yet implemented.

This also renames SpiderWASM, which isn't camel-case, to Baldrdash,
which is, and which is also a more relevant name.
This commit is contained in:
Dan Gohman
2018-04-22 21:35:18 -07:00
committed by GitHub
parent 8a9e4b9cff
commit c5b15c2396
38 changed files with 226 additions and 161 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
lib/codegen/src/isa/x86/abi.rs
View File

@@ -6,12 +6,12 @@ use cursor::{Cursor, CursorPosition, EncCursor};
use ir;
use ir::immediates::Imm64;
use ir::stackslot::{StackOffset, StackSize};
use ir::{AbiParam, ArgumentExtension, ArgumentLoc, ArgumentPurpose, CallConv, InstBuilder,
ValueLoc};
use ir::{AbiParam, ArgumentExtension, ArgumentLoc, ArgumentPurpose, InstBuilder, ValueLoc};
use isa::{RegClass, RegUnit, TargetIsa};
use regalloc::RegisterSet;
use result;
use settings as shared_settings;
use settings::CallConv;
use stack_layout::layout_stack;
use std::i32;
@@ -74,7 +74,7 @@ impl ArgAssigner for Args {
}
// Handle special-purpose arguments.
if ty.is_int() && self.call_conv == CallConv::SpiderWASM {
if ty.is_int() && self.call_conv == CallConv::Baldrdash {
match arg.purpose {
// This is SpiderMonkey's `WasmTlsReg`.
ArgumentPurpose::VMContext => {
@@ -210,19 +210,20 @@ fn callee_saved_gprs_used(flags: &shared_settings::Flags, func: &ir::Function) -
pub fn prologue_epilogue(func: &mut ir::Function, isa: &TargetIsa) -> result::CtonResult {
match func.signature.call_conv {
ir::CallConv::SystemV => system_v_prologue_epilogue(func, isa),
ir::CallConv::SpiderWASM => spiderwasm_prologue_epilogue(func, isa),
// For now, just translate fast and cold as system_v.
CallConv::Fast | CallConv::Cold | CallConv::SystemV => {
system_v_prologue_epilogue(func, isa)
}
CallConv::Fastcall => unimplemented!("Windows calling conventions"),
CallConv::Baldrdash => baldrdash_prologue_epilogue(func, isa),
}
}
pub fn spiderwasm_prologue_epilogue(
func: &mut ir::Function,
isa: &TargetIsa,
) -> result::CtonResult {
// Spiderwasm on 32-bit x86 always aligns its stack pointer to 16 bytes.
pub fn baldrdash_prologue_epilogue(func: &mut ir::Function, isa: &TargetIsa) -> result::CtonResult {
// Baldrdash on 32-bit x86 always aligns its stack pointer to 16 bytes.
let stack_align = 16;
let word_size = if isa.flags().is_64bit() { 8 } else { 4 };
let bytes = StackSize::from(isa.flags().spiderwasm_prologue_words()) * word_size;
let bytes = StackSize::from(isa.flags().baldrdash_prologue_words()) * word_size;
let mut ss = ir::StackSlotData::new(ir::StackSlotKind::IncomingArg, bytes);
ss.offset = Some(-(bytes as StackOffset));