• Cecil Ward (6/6) Jul 25 2023 Is a dchar a signed 32-bit number? LDC seems to think so, as I
• Richard (Rikki) Andrew Cattermole (2/2) Jul 25 2023 The spec says they are unsigned, so if ldc is using sign extension, that...
• Cecil Ward (9/11) Jul 27 2023 My fault, I reread the code and the sign-extension applies to

Cecil Ward <cecil cecilward.com> writes:

Is a dchar a signed 32-bit number? LDC seems to think so, as I 
spotted it in Compiler Explorer sign-extending from 32 to 64-bits 
for some very odd reason. Do we really want it to be signed? 
(Please answer ‘no’, as this could lead to some bugs, although 
the range of legitimate Unicode code points is quite limited, 
being only, what, 17 * 65536 roughly.)

"Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:

The spec says they are unsigned, so if ldc is using sign extension, that 
is probably a bug.

Cecil Ward <cecil cecilward.com> writes:

On Wednesday, 26 July 2023 at 01:56:28 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
 The spec says they are unsigned, so if ldc is using sign 
 extension, that is probably a bug.

My fault, I reread the code and the sign-extension applies to 
something else, coincidentally right where I was looking at this. 
It uses signed 32-bit displacements in a case/switch table of 
offsets into the code segment, and that was what mislead me. It 
could have used unsigned displacements but then all the labels in 
the code would have to be above the reference base point, and 
this allows +/- offsets to anywhere. So my apologies.