bjoernager/rust
bjoernager/rust
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Revert "Remove shift amount masking"

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This reverts commit c5f98b586f.

It turns out to be necessary anyway
This commit is contained in:
bjorn3 2021-02-21 14:39:31 +01:00
parent 0610490c8d
commit 7fc34839ac
1 changed files with 20 additions and 6 deletions
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26
src/num.rs
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@ -168,12 +168,20 @@ pub(crate) fn codegen_int_binop<'tcx>(
BinOp::BitXor => b.bxor(lhs, rhs), BinOp::BitXor => b.bxor(lhs, rhs),
BinOp::BitAnd => b.band(lhs, rhs), BinOp::BitAnd => b.band(lhs, rhs),
BinOp::BitOr => b.bor(lhs, rhs), BinOp::BitOr => b.bor(lhs, rhs),
BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs), BinOp::Shl => {
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);
fx.bcx.ins().ishl(lhs, actual_shift)
}
BinOp::Shr => { 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);
if signed { if signed {
fx.bcx.ins().sshr(lhs, rhs) fx.bcx.ins().sshr(lhs, actual_shift)
} else { } else {
fx.bcx.ins().ushr(lhs, rhs) fx.bcx.ins().ushr(lhs, actual_shift)
} }
} }
// Compare binops handles by `codegen_binop`. // Compare binops handles by `codegen_binop`.
@ -295,7 +303,10 @@ pub(crate) fn codegen_checked_int_binop<'tcx>(
} }
} }
BinOp::Shl => { 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 ty = fx.bcx.func.dfg.value_type(val);
let max_shift = i64::from(ty.bits()) - 1; let max_shift = i64::from(ty.bits()) - 1;
let has_overflow = fx let has_overflow = fx
@ -305,10 +316,13 @@ pub(crate) fn codegen_checked_int_binop<'tcx>(
(val, has_overflow) (val, has_overflow)
} }
BinOp::Shr => { 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 { let val = if !signed {
fx.bcx.ins().ushr(lhs, rhs) fx.bcx.ins().ushr(lhs, actual_shift)
} else { } else {
fx.bcx.ins().sshr(lhs, rhs) fx.bcx.ins().sshr(lhs, actual_shift)
}; };
let ty = fx.bcx.func.dfg.value_type(val); let ty = fx.bcx.func.dfg.value_type(val);
let max_shift = i64::from(ty.bits()) - 1; let max_shift = i64::from(ty.bits()) - 1;