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stage1: Byteswap floats when serializing them

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This commit is contained in:
LemonBoy 2020-04-04 16:46:39 +02:00
parent 084c62f5d1
commit ad2ebc87f2
1 changed files with 65 additions and 36 deletions
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101
src/ir.cpp
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@ -10993,48 +10993,77 @@ static void float_negate(ZigValue *out_val, ZigValue *op) {
}
void float_write_ieee597(ZigValue *op, uint8_t *buf, bool is_big_endian) {
if (op->type->id == ZigTypeIdFloat) {
switch (op->type->data.floating.bit_count) {
case 16:
memcpy(buf, &op->data.x_f16, 2); // TODO wrong when compiler is big endian
return;
case 32:
memcpy(buf, &op->data.x_f32, 4); // TODO wrong when compiler is big endian
return;
case 64:
memcpy(buf, &op->data.x_f64, 8); // TODO wrong when compiler is big endian
return;
case 128:
memcpy(buf, &op->data.x_f128, 16); // TODO wrong when compiler is big endian
return;
default:
zig_unreachable();
}
} else {
if (op->type->id != ZigTypeIdFloat)
zig_unreachable();
const unsigned n = op->type->data.floating.bit_count / 8;
assert(n <= 16);
switch (op->type->data.floating.bit_count) {
case 16:
memcpy(buf, &op->data.x_f16, 2);
break;
case 32:
memcpy(buf, &op->data.x_f32, 4);
break;
case 64:
memcpy(buf, &op->data.x_f64, 8);
break;
case 128:
memcpy(buf, &op->data.x_f128, 16);
break;
default:
zig_unreachable();
}
if (is_big_endian) {
// Byteswap in place if needed
for (size_t i = 0; i < n / 2; i++) {
uint8_t u = buf[i];
buf[i] = buf[n - 1 - i];
buf[n - 1 - i] = u;
}
}
}
void float_read_ieee597(ZigValue *val, uint8_t *buf, bool is_big_endian) {
if (val->type->id == ZigTypeIdFloat) {
switch (val->type->data.floating.bit_count) {
case 16:
memcpy(&val->data.x_f16, buf, 2); // TODO wrong when compiler is big endian
return;
case 32:
memcpy(&val->data.x_f32, buf, 4); // TODO wrong when compiler is big endian
return;
case 64:
memcpy(&val->data.x_f64, buf, 8); // TODO wrong when compiler is big endian
return;
case 128:
memcpy(&val->data.x_f128, buf, 16); // TODO wrong when compiler is big endian
return;
default:
zig_unreachable();
}
} else {
if (val->type->id != ZigTypeIdFloat)
zig_unreachable();
const unsigned n = val->type->data.floating.bit_count / 8;
assert(n <= 16);
uint8_t tmp[16];
uint8_t *ptr = buf;
if (is_big_endian) {
memcpy(tmp, buf, n);
// Byteswap if needed
for (size_t i = 0; i < n / 2; i++) {
uint8_t u = tmp[i];
tmp[i] = tmp[n - 1 - i];
tmp[n - 1 - i] = u;
}
ptr = tmp;
}
switch (val->type->data.floating.bit_count) {
case 16:
memcpy(&val->data.x_f16, ptr, 2);
return;
case 32:
memcpy(&val->data.x_f32, ptr, 4);
return;
case 64:
memcpy(&val->data.x_f64, ptr, 8);
return;
case 128:
memcpy(&val->data.x_f128, ptr, 16);
return;
default:
zig_unreachable();
}
}