search for: dsub0

...wed to coalesce a COPY that uses a subreg as a destination? I've got the following sequence of code (unfortunately for an out of tree target) that is moving 32 and 64 bit sub-registers around within a 128 bit register. By the time the register allocator runs the code looks like: 92L %reg16402:dsub0<def> = DEF64.. %reg16402<imp-def>, QPR:%reg16402.... 116L %reg16405:sub0<def> = COPY %reg16402:sub1, %reg16405<imp-def>; QPR:%reg16405,16402 124L %reg16413:sub0<def> = COPY %reg16405:sub0<kill>; QPR:%reg16413,16405 .... stuff .... 468L %reg16460:sub3<def>...

Does anyone know exactly what ComposerIndices in Target.td is all about? I see just one place where it's used in X86 but it's not clear from the comments in Target.td and it's one usage, exactly what this feature is about. Tia. Reed