- Copy propagation through an FPR temp didn't stop when an instruction
rewrote the temp in place (it compared an FPR number against the +32
offset reg), so later reads lost that write.
- A read of the temp in both operands only had src1 replaced, yet the copy
into the temp was still removed.
- The replacement matched operands by number without checking their type,
so a StoreFloat whose GPR address had the temp's number got its address
replaced (IRVTEMP_PFX_S and IRTEMP_0 are both 192).
- A write to lanes 1-3 of a Vec4 temp wasn't noticed.
- IRReadsFromFPRs stopped after the F operands, missing Vec4Scale's vector.
- Exits and barriers didn't count as reading everything, so a write to a
real reg could be moved above an exit.
- Load32Linked and Store32Conditional were removed when their reg was
overwritten unread, losing LLBIT and the store.
Also fixes an off-by-one in the vec src3 read check. The unit test now
reports every failing case instead of stopping at the first.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
