ddc493579f
This is an optimisation patch that shouldn't have any functional effect.
There's no need for all instructions to have a DPMarker attached to them,
because not all instructions have adjacent DPValues (aka dbg.values).
This patch inserts the appropriate conditionals into functions like
BasicBlock::spliceDebugInfo to ensure we don't step on a null pointer when
there isn't a DPMarker allocated. Mostly, this is a case of calling
createMarker occasionally, which will create a marker on an instruction
if there isn't one there already.
Also folded into this is the use of adoptDbgValues, which is a natural
extension: if we have a sequence of instructions and debug records:
%foo = add i32 %0,...
# dbg_value { %foo, ...
# dbg_value { %bar, ...
%baz = add i32 %...
%qux = add i32 %...
and delete, for example, the %baz instruction, then the dbg_value records
would naturally be transferred onto the %qux instruction (they "fall down"
onto it). There's no point in creating and splicing DPMarkers in the case
shown when %qux doesn't have a DPMarker already, we can instead just change
the owner of %baz's DPMarker from %baz to %qux. This also avoids calling
setParent on every DPValue.
Update LoopRotationUtils: it was relying on each instruction having it's
own distinct end(), so that we could express ranges and lack-of-ranges.
That's no longer true though: so switch to storing the range of DPValues on
the next instruction when we want to consider it's range next time around
the loop (see the nearby comment).
43 KiB
43 KiB