wasm: fixes for signed saturation

This commit is contained in:
Luuk de Gram 2022-06-19 17:26:44 +02:00
parent 05600a6d84
commit a50147bfff
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@ -4939,9 +4939,9 @@ fn signedSat(self: *Self, lhs_operand: WValue, rhs_operand: WValue, ty: Type, op
const rhs = if (!is_wasm_bits) try self.signAbsValue(rhs_operand, ty) else rhs_operand;
const max_val: u64 = @intCast(u64, (@as(u65, 1) << @intCast(u7, int_info.bits - 1)) - 1);
const min_val = @intCast(i64, ~@intCast(u63, max_val));
const min_val: i64 = (-@intCast(i64, @intCast(u63, max_val))) - 1;
const max_wvalue = switch (wasm_bits) {
32 => WValue{ .imm32 = @intCast(u32, max_val) },
32 => WValue{ .imm32 = @truncate(u32, max_val) },
64 => WValue{ .imm64 = max_val },
else => unreachable,
};
@ -4975,7 +4975,7 @@ fn signedSat(self: *Self, lhs_operand: WValue, rhs_operand: WValue, ty: Type, op
};
const cmp_bin_result = try self.cmp(bin_result, lhs, ty, .lt);
const cmp_zero_result = try self.cmp(rhs, zero, ty, if (op == .add) .lt else .gt);
const xor = try self.binOp(cmp_zero_result, cmp_bin_result, ty, .xor);
const xor = try self.binOp(cmp_zero_result, cmp_bin_result, Type.u32, .xor); // comparisons always return i32, so provide u32 as type to xor.
const cmp_bin_zero_result = try self.cmp(bin_result, zero, ty, .lt);
try self.emitWValue(max_wvalue);
try self.emitWValue(min_wvalue);
@ -5084,6 +5084,10 @@ fn airShlSat(self: *Self, inst: Air.Inst.Index) InnerError!WValue {
try self.emitWValue(cmp_result);
try self.addTag(.select);
try self.addLabel(.local_set, result.local);
return self.binOp(result, shift_value, ty, .shr);
const shift_result = try self.binOp(result, shift_value, ty, .shr);
if (is_signed) {
return self.wrapOperand(shift_result, ty);
}
return shift_result;
}
}