From c47402416bf611fa2b7742abfa94ddcef8e5501a Mon Sep 17 00:00:00 2001
From: llogiq <bogusandre@gmail.com>
Date: Mon, 17 Aug 2015 15:11:36 +0200
Subject: [PATCH] Added bit operations to const folding
---
src/consts.rs | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/src/consts.rs b/src/consts.rs
index e39faf9e39a..01fb3520f2c 100644
--- a/src/consts.rs
+++ b/src/consts.rs
@@ -402,11 +402,11 @@ fn constant_binop(cx: &Context, op: BinOp, left: &Expr, right: &Expr)
//BiRem,
BiAnd => constant_short_circuit(cx, left, right, false),
BiOr => constant_short_circuit(cx, left, right, true),
- //BiBitXor,
- //BiBitAnd,
- //BiBitOr,
- //BiShl,
- //BiShr,
+ BiBitXor => constant_bitop(cx, left, right, |x, y| x ^ y),
+ BiBitAnd => constant_bitop(cx, left, right, |x, y| x & y),
+ BiBitOr => constant_bitop(cx, left, right, |x, y| (x | y)),
+ BiShl => constant_bitop(cx, left, right, |x, y| x << y),
+ BiShr => constant_bitop(cx, left, right, |x, y| x >> y),
BiEq => constant_binop_apply(cx, left, right,
|l, r| Some(ConstantBool(l == r))),
BiNe => constant_binop_apply(cx, left, right,
@@ -415,10 +415,23 @@ fn constant_binop(cx: &Context, op: BinOp, left: &Expr, right: &Expr)
BiLe => constant_cmp(cx, left, right, Greater, false),
BiGe => constant_cmp(cx, left, right, Less, false),
BiGt => constant_cmp(cx, left, right, Greater, true),
- _ => None,
+ _ => None
}
}
+fn constant_bitop<F>(cx: &Context, left: &Expr, right: &Expr, f: F)
+ -> Option<Constant> where F: Fn(u64, u64) -> u64 {
+ constant_binop_apply(cx, left, right, |l, r| match (l, r) {
+ (ConstantBool(l), ConstantBool(r)) =>
+ Some(ConstantBool(f(l as u64, r as u64) != 0)),
+ (ConstantByte(l8), ConstantByte(r8)) =>
+ Some(ConstantByte(f(l8 as u64, r8 as u64) as u8)),
+ (ConstantInt(l, lty), ConstantInt(r, rty)) =>
+ unify_int_type(lty, rty, Plus).map(|ty| ConstantInt(f(l, r), ty)),
+ _ => None
+ })
+}
+
fn constant_cmp(cx: &Context, left: &Expr, right: &Expr, ordering: Ordering,
b: bool) -> Option<Constant> {
constant_binop_apply(cx, left, right, |l, r| l.partial_cmp(&r).map(|o|