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Sema: remove incorrect safety check for saturating left shift #24411

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Merged
merged 1 commit into from
Jul 30, 2025
Merged

Sema: remove incorrect safety check for saturating left shift #24411

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2 changes: 1 addition & 1 deletion src/Sema.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -14134,7 +14134,7 @@ fn zirShl(
try sema.requireRuntimeBlock(block, src, runtime_src);
if (block.wantSafety()) {
const bit_count = scalar_ty.intInfo(zcu).bits;
if (!std.math.isPowerOfTwo(bit_count)) {
if (air_tag != .shl_sat and !std.math.isPowerOfTwo(bit_count)) {
const bit_count_val = try pt.intValue(scalar_rhs_ty, bit_count);
const ok = if (rhs_ty.zigTypeTag(zcu) == .vector) ok: {
const bit_count_inst = Air.internedToRef((try sema.splat(rhs_ty, bit_count_val)).toIntern());
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2 changes: 0 additions & 2 deletions test/behavior/bit_shifting.zig
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Expand Up @@ -169,8 +169,6 @@ test "Saturating Shift Left" {

const S = struct {
fn shlSat(x: anytype, y: std.math.Log2Int(@TypeOf(x))) @TypeOf(x) {
// workaround https://github.com/ziglang/zig/issues/23033
@setRuntimeSafety(false);
return x <<| y;
}

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2 changes: 0 additions & 2 deletions test/behavior/x86_64/binary.zig
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Expand Up @@ -5473,8 +5473,6 @@ inline fn shlSaturate(comptime Type: type, lhs: Type, rhs: Type) Type {
// workaround https://github.com/ziglang/zig/issues/23139
return lhs <<| @min(@abs(rhs), splat(ChangeScalar(Type, u64), imax(u64)));
}
// workaround https://github.com/ziglang/zig/issues/23033
@setRuntimeSafety(false);
return lhs <<| @abs(rhs);
}
test shlSaturate {
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