bjoernager/rust
bjoernager/rust
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Mask shift amount

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This commit is contained in:
bjorn3 2020-05-01 14:13:03 +02:00
parent e2ab2885c2
commit cc0268fa1a
1 changed files with 16 additions and 8 deletions
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24
src/num.rs
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@ -168,16 +168,18 @@ pub(crate) fn trans_int_binop<'tcx>(
BinOp::BitOr => b.bor(lhs, rhs),
BinOp::Shl => {
let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
let rhs = clif_intcast(fx, rhs, lhs_ty, false);
fx.bcx.ins().ishl(lhs, rhs)
let actual_shift = fx.bcx.ins().band_imm(rhs, i64::from(lhs_ty.bits() - 1));
let actual_shift = clif_intcast(fx, actual_shift, types::I8, false);
fx.bcx.ins().ishl(lhs, actual_shift)
}
BinOp::Shr => {
let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
let rhs = clif_intcast(fx, rhs, lhs_ty, false);
let actual_shift = fx.bcx.ins().band_imm(rhs, i64::from(lhs_ty.bits() - 1));
let actual_shift = clif_intcast(fx, actual_shift, types::I8, false);
if signed {
fx.bcx.ins().sshr(lhs, rhs)
fx.bcx.ins().sshr(lhs, actual_shift)
} else {
fx.bcx.ins().ushr(lhs, rhs)
fx.bcx.ins().ushr(lhs, actual_shift)
}
}
// Compare binops handles by `codegen_binop`.
@ -283,7 +285,10 @@ pub(crate) fn trans_checked_int_binop<'tcx>(
}
}
BinOp::Shl => {
let val = fx.bcx.ins().ishl(lhs, rhs);
let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
let actual_shift = fx.bcx.ins().band_imm(rhs, i64::from(lhs_ty.bits() - 1));
let actual_shift = clif_intcast(fx, actual_shift, types::I8, false);
let val = fx.bcx.ins().ishl(lhs, actual_shift);
let ty = fx.bcx.func.dfg.value_type(val);
let max_shift = i64::from(ty.bits()) - 1;
let has_overflow =
@ -291,10 +296,13 @@ pub(crate) fn trans_checked_int_binop<'tcx>(
(val, has_overflow)
}
BinOp::Shr => {
let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
let actual_shift = fx.bcx.ins().band_imm(rhs, i64::from(lhs_ty.bits() - 1));
let actual_shift = clif_intcast(fx, actual_shift, types::I8, false);
let val = if !signed {
fx.bcx.ins().ushr(lhs, rhs)
fx.bcx.ins().ushr(lhs, actual_shift)
} else {
fx.bcx.ins().sshr(lhs, rhs)
fx.bcx.ins().sshr(lhs, actual_shift)
};
let ty = fx.bcx.func.dfg.value_type(val);
let max_shift = i64::from(ty.bits()) - 1;