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x86_64: fix SystemV calling convention

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This commit is contained in:
Jakub Konka 2022-09-04 21:27:26 +02:00
parent 56a131d27a
commit 467d69c68a
1 changed files with 19 additions and 12 deletions
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31
src/arch/x86_64/CodeGen.zig
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@ -7216,19 +7216,23 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) !CallMCValues {
for (param_types) |ty, i| {
assert(ty.hasRuntimeBits());
if (self.target.os.tag != .windows) {
return self.fail("TODO SysV calling convention", .{});
const classes: []const abi.Class = switch (self.target.os.tag) {
.windows => &[1]abi.Class{abi.classifyWindows(ty, self.target.*)},
else => mem.sliceTo(&abi.classifySystemV(ty, self.target.*), .none),
};
if (classes.len > 1) {
return self.fail("TODO handle multiple classes per type", .{});
}
switch (abi.classifyWindows(ty, self.target.*)) {
switch (classes[0]) {
.integer => blk: {
if (i >= abi.getCAbiIntParamRegs(self.target.*).len) break :blk; // fallthrough
result.args[i] = .{ .register = abi.getCAbiIntParamRegs(self.target.*)[i] };
continue;
},
.sse => return self.fail("TODO float/vector via SSE on Windows", .{}),
.memory => {}, // fallthrough
else => unreachable,
else => |class| return self.fail("TODO handle calling convention class {s}", .{
@tagName(class),
}),
}
const param_size = @intCast(u32, ty.abiSize(self.target.*));
@ -7237,7 +7241,8 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) !CallMCValues {
result.args[i] = .{ .stack_offset = @intCast(i32, offset) };
next_stack_offset = offset;
}
// Align the stack to 16bytes before allocating shadow stack space.
// Align the stack to 16bytes before allocating shadow stack space (if any).
const aligned_next_stack_offset = mem.alignForwardGeneric(u32, next_stack_offset, 16);
const padding = aligned_next_stack_offset - next_stack_offset;
if (padding > 0) {
@ -7247,11 +7252,13 @@ fn resolveCallingConventionValues(self: *Self, fn_ty: Type) !CallMCValues {
}
}
// TODO fix this so that the 16byte alignment padding is at the current value of $rsp, and push
// the args onto the stack so that there is no padding between the first argument and
// the standard preamble.
// alignment padding | ret value (if > 8) | args ... | shadow stack space | $rbp |
result.stack_byte_count = aligned_next_stack_offset + 4 * @sizeOf(u64);
const shadow_stack_space: u32 = switch (self.target.os.tag) {
.windows => @intCast(u32, 4 * @sizeOf(u64)),
else => 0,
};
// alignment padding | args ... | shadow stack space (if any) | ret addr | $rbp |
result.stack_byte_count = aligned_next_stack_offset + shadow_stack_space;
result.stack_align = 16;
},
.Unspecified => {