Displaying 1 result from an estimated 1 matches for "preferredalignment".
2011 Feb 14
1
[LLVMdev] broken alignment in stack(caused by bug in SelectionDAGBuilder) causes invalid schedules with r125471 and newer
...ign information, this optimization breaks and it incorrectly optimizes add by 4 into xor by 4, when the object is (in reality) aligned by 4, not by 8(which MFI thinks about it's alignment)
Two solutions come into my mind:
1) changiing the SelectionDAGBuilder to use std::min(StackAlignment, PreferredAlignment) instead of PreferredAlignment. This might require asserting (StackAlignment <= ABI alignment).
2) changing the SelectionAGBuilder to use ABI alignment instead of the preferred alignment for the stack objects.
The affected code lines are around 4820, and 5694 of SelectionDAGBuilder.cpp