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Minor cleanup

master
Noam Preil 2020-05-17 04:47:25 -04:00 committed by Andrew Kelley
parent 497eb31820
commit e2196a458f
1 changed files with 8 additions and 8 deletions
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16
src-self-hosted/codegen.zig
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@ -379,12 +379,12 @@ const Function = struct {
return self.code.appendSlice(&[_]u8{
0x45,
0x31,
0xC0 | (@intCast(u8, @truncate(u3, reg.id())) << 3) | @truncate(u3, reg.id()),
0xC0 | (@as(u8, reg.id() & 0b111) << 3) | @truncate(u3, reg.id()),
});
} else {
return self.code.appendSlice(&[_]u8{
0x31,
0xC0 | (@intCast(u8, reg.id()) << 3) | @intCast(u3, reg.id()),
0xC0 | (@as(u8, reg.id()) << 3) | reg.id(),
});
}
}
@ -403,7 +403,7 @@ const Function = struct {
} else {
try self.code.resize(self.code.items.len + 5);
}
self.code.items[self.code.items.len - 5] = 0xB8 | @intCast(u8, @truncate(u3, reg.id()));
self.code.items[self.code.items.len - 5] = 0xB8 | @as(u8, reg.id() & 0b111);
const imm_ptr = self.code.items[self.code.items.len - 4 ..][0..4];
mem.writeIntLittle(u32, imm_ptr, @intCast(u32, x));
return;
@ -422,7 +422,7 @@ const Function = struct {
const REX = 0x48 | (if (reg.isExtended()) @as(u8, 0x01) else 0);
try self.code.resize(self.code.items.len + 10);
self.code.items[self.code.items.len - 10] = REX;
self.code.items[self.code.items.len - 9] = 0xB8 | @intCast(u8, @truncate(u3, reg.id()));
self.code.items[self.code.items.len - 9] = 0xB8 | @as(u8, reg.id() & 0b111);
const imm_ptr = self.code.items[self.code.items.len - 8 ..][0..8];
mem.writeIntLittle(u64, imm_ptr, x);
},
@ -444,7 +444,7 @@ const Function = struct {
const offset = @intCast(i32, big_offset);
self.code.items[self.code.items.len - 7] = REX;
self.code.items[self.code.items.len - 6] = 0x8D;
self.code.items[self.code.items.len - 5] = 0x5 | (@intCast(u8, @truncate(u3, reg.id())) << 3);
self.code.items[self.code.items.len - 5] = 0b101 | (@as(u8, reg.id() & 0b111) << 3);
const imm_ptr = self.code.items[self.code.items.len - 4 ..][0..4];
mem.writeIntLittle(i32, imm_ptr, offset);
},
@ -460,7 +460,7 @@ const Function = struct {
// Since the register is being accessed directly, the R/M mode is three. The reg field (the middle
// three bits) contain the destination, and the R/M field (the lower three bits) contain the source.
const REX = 0x48 | (if (reg.isExtended()) @as(u8, 4) else 0) | (if (src_reg.isExtended()) @as(u8, 1) else 0);
const R = 0xC0 | (@intCast(u8, @truncate(u3, reg.id())) << 3) | @truncate(u3, src_reg.id());
const R = 0xC0 | (@as(u8, reg.id() & 0b111) << 3) | @truncate(u3, src_reg.id());
try self.code.appendSlice(&[_]u8{ REX, 0x8B, R });
},
.memory => |x| {
@ -477,7 +477,7 @@ const Function = struct {
// The instruction is thus eight bytes; REX 0x8B 0b00RRR100 0x25 followed by a four-byte disp32.
try self.code.resize(self.code.items.len + 8);
const REX = 0x48 | if (reg.isExtended()) @as(u8, 1) else 0;
const r = 0x04 | (@intCast(u8, @truncate(u3, reg.id())) << 3);
const r = 0x04 | (@as(u8, reg.id() & 0b111) << 3);
self.code.items[self.code.items.len - 8] = REX;
self.code.items[self.code.items.len - 7] = 0x8B;
self.code.items[self.code.items.len - 6] = r;
@ -521,7 +521,7 @@ const Function = struct {
// Furthermore, if this is an extended register, both B and R must be set in the REX byte, as *both*
// register operands need to be marked as extended.
const REX = 0x48 | if (reg.isExtended()) @as(u8, 0b0101) else 0;
const RM = (@intCast(u8, @truncate(u3, reg.id())) << 3) | @truncate(u3, reg.id());
const RM = (@as(u8, reg.id() & 0b111) << 3) | @truncate(u3, reg.id());
try self.code.appendSlice(&[_]u8{ REX, 0x8B, RM });
}
}