On Tue, 3 Oct 2023 09:05:17 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Lower.java line 2982: >> >>> 2980: // => >>> 2981: // if (let tmp$123 = v; >>> ExactnessChecks.int_float(tmp$123)) >>> 2982: JCIdent argument = make.Ident(dollar_s); >> >> In principle you don't need a synthetic variable here... (but it's ok if you >> prefer to leave for uniformity) > > Aren't there cases here where the type of the expr is unconditional w.r.t. > the type of the pattern (and so, no test is required) ? Perhaps the case I'm > thinking of is dealt with one of the ifs at the beginning of this method. > > I have to say I'm a bit confused by how this method is arranged. From a > logical perspective I would expect first and foremost to test if the pattern > type is a primitive, because that's the only case where Lower needs to do > anything (right?). > > Then you can have two cases: the expression has a reference type, in which > case you need null check and unboxing. Or the expression has a primitive type. > > In both cases you can be in a situation where the conversion is provably > exact, so no need to call the exactness routine - or you can be in an inexact > situation where a runtime test is required. > > While I'm sure that is what happens in the above code, I think perhaps the > various tests could be arranged in a way to make the above structure pop out > a little more? Refactoring attempt No. 1 complete. I need to recheck the completeness of `checkUnconditionallyExact`. In a following commit. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/15638#discussion_r1346993616
