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librustc: emit loop for expr_repeat instead of 2n instructions in [x, ..n]

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This commit is contained in:
Luqman Aden 2013-03-24 00:59:44 -07:00
parent a56ec8c134
commit 441313fc0c
1 changed files with 41 additions and 16 deletions
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57
src/librustc/middle/trans/tvec.rs
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@ -27,6 +27,7 @@ use middle::ty;
use util::common::indenter;
use util::ppaux::ty_to_str;
use core::option::None;
use core::uint;
use core::vec;
use syntax::ast;
@ -413,30 +414,54 @@ pub fn write_content(bcx: block,
return bcx;
}
let tmpdatum = unpack_datum!(bcx, {
let elem = unpack_datum!(bcx, {
expr::trans_to_datum(bcx, element)
});
let mut temp_cleanups = ~[];
let next_bcx = sub_block(bcx, ~"expr_repeat: while next");
let loop_bcx = loop_scope_block(bcx, next_bcx, None, ~"expr_repeat", None);
let cond_bcx = scope_block(loop_bcx, None, ~"expr_repeat: loop cond");
let set_bcx = scope_block(loop_bcx, None, ~"expr_repeat: body: set");
let inc_bcx = scope_block(loop_bcx, None, ~"expr_repeat: body: inc");
Br(bcx, loop_bcx.llbb);
for uint::range(0, count) |i| {
let lleltptr = GEPi(bcx, lldest, [i]);
if i < count - 1 {
// Copy all but the last one in.
bcx = tmpdatum.copy_to(bcx, INIT, lleltptr);
} else {
// Move the last one in.
bcx = tmpdatum.move_to(bcx, INIT, lleltptr);
}
add_clean_temp_mem(bcx, lleltptr, vt.unit_ty);
temp_cleanups.push(lleltptr);
let loop_counter = {
// i = 0
let i = alloca(loop_bcx, T_i64());
Store(loop_bcx, C_i64(0), i);
Br(loop_bcx, cond_bcx.llbb);
i
};
{ // i < count
let lhs = Load(cond_bcx, loop_counter);
let rhs = C_integral(T_i64(), count as u64, lib::llvm::False);
let cmp_lr = ICmp(cond_bcx, lib::llvm::IntULT, lhs, rhs);
let zext = ZExt(cond_bcx, cmp_lr, T_i8());
let cond_val = ICmp(cond_bcx, lib::llvm::IntNE, zext, C_u8(0));
CondBr(cond_bcx, cond_val, set_bcx.llbb, next_bcx.llbb);
}
for vec::each(temp_cleanups) |cleanup| {
revoke_clean(bcx, *cleanup);
{ // v[i] = elem
let i = Load(set_bcx, loop_counter);
let lleltptr = InBoundsGEP(set_bcx, lldest, [i]);
let set_bcx = elem.copy_to(set_bcx, INIT, lleltptr);
Br(set_bcx, inc_bcx.llbb);
}
return bcx;
{ // i += 1
let i = Load(inc_bcx, loop_counter);
let plusone = Add(inc_bcx, i, C_i64(1));
Store(inc_bcx, plusone, loop_counter);
Br(inc_bcx, cond_bcx.llbb);
}
return next_bcx;
}
}
}