OpenE2K/rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

librustc: Add a small vector optimization for GEPi. Shaves a second off trans, I think?

Browse Source
This commit is contained in:
Patrick Walton 2013-06-07 19:59:32 -07:00 committed by Corey Richardson
parent 90ad444287
commit f463e69d20
1 changed files with 14 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/librustc/middle/trans/build.rs
View File

@ -610,12 +610,21 @@ pub fn GEP(cx: block, Pointer: ValueRef, Indices: &[ValueRef]) -> ValueRef {
// Simple wrapper around GEP that takes an array of ints and wraps them
// in C_i32()
//
// FIXME #6571: Use a small-vector optimization to avoid allocations here.
#[inline]
pub fn GEPi(cx: block, base: ValueRef, ixs: &[uint]) -> ValueRef {
let v = do vec::map(ixs) |i| { C_i32(*i as i32) };
count_insn(cx, "gepi");
return InBoundsGEP(cx, base, v);
// Small vector optimization. This should catch 100% of the cases that
// we care about.
if ixs.len() < 16 {
let mut small_vec = [ C_i32(0), ..16 ];
for ixs.eachi |i, &ix| {
small_vec[i] = C_i32(ix as i32)
}
InBoundsGEP(cx, base, small_vec.slice(0, ixs.len()))
} else {
let v = do vec::map(ixs) |i| { C_i32(*i as i32) };
count_insn(cx, "gepi");
InBoundsGEP(cx, base, v)
}
}
pub fn InBoundsGEP(cx: block, Pointer: ValueRef, Indices: &[ValueRef]) -> ValueRef {