Commit Graph

4 Commits

Author SHA1 Message Date
Bill Wendling a5c536e1ee Use function attributes to indicate that we don't want to realign the stack.
Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.

llvm-svn: 187618
2013-08-01 21:42:05 +00:00
Bob Wilson 67bbf3aa0c Revert 172027 and 174336. Remove diagnostics about over-aligned stack objects.
Aside from the question of whether we report a warning or an error when we
can't satisfy a requested stack object alignment, the current implementation
of this is not good.  We're not providing any source location in the diagnostics
and the current warning is not connected to any warning group so you can't
control it.  We could improve the source location somewhat, but we can do a
much better job if this check is implemented in the front-end, so let's do that
instead.  <rdar://problem/13127907>

llvm-svn: 174741
2013-02-08 20:35:15 +00:00
Manman Ren 207bcbacca Stack Alignment: throw error if we can't satisfy the minimal alignment
requirement when creating stack objects in MachineFrameInfo.

Add CreateStackObjectWithMinAlign to throw error when the minimal alignment
can't be achieved and to clamp the alignment when the preferred alignment
can't be achieved. Same is true for CreateVariableSizedObject.
Will not emit error in CreateSpillStackObject or CreateStackObject.

As long as callers of CreateStackObject do not assume the object will be
aligned at the requested alignment, we should not have miscompile since
later optimizations which look at the object's alignment will have the correct
information.

rdar://12713765

llvm-svn: 172027
2013-01-10 01:10:10 +00:00
Manman Ren f563941adc Stack Alignment: when creating stack objects in MachineFrameInfo, make sure
the alignment is clamped to TargetFrameLowering.getStackAlignment if the target
does not support stack realignment or the option "realign-stack" is off.

This will cause miscompile if the address is treated as aligned and add is
replaced with or in DAGCombine.

Added a bool StackRealignable to TargetFrameLowering to check whether stack
realignment is implemented for the target. Also added a bool RealignOption
to MachineFrameInfo to check whether the option "realign-stack" is on.

rdar://12713765

llvm-svn: 169197
2012-12-04 00:52:33 +00:00