[PATCH] D31604: [DebugInfo][X86] Improve X86 Optimize LEAs handling of debug values.

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added inline comments.


================
Comment at: lib/Target/X86/X86OptimizeLEAs.cpp:555
+      // Can't do this with DWARF version less than 4 as we need support for
+      // DW_OP_stack_value, so remove.
+      MI.eraseFromParent();
----------------
aprantl wrote:
> andrewng wrote:
> > aprantl wrote:
> > > This is for the backend to decide and discard. We shouldn't have any DWARF version specific code here. (E.g.: what if we generate CodeView debug info?)
> > > 
> > > After landing https://reviews.llvm.org/D31439, DwarfExpression can actually drop locations that can not be expressed in the requested DWARF version.
> > OK, so I should just generate the DIExpression with the DW_OP_stack_value operation and the backend will discard the DBG_VALUE if the DWARF version is not compatible (in the case of DWARF debug info)?
> Yes, please. Note that the backend cannot (yet) doe this, but I will hopefully be able to land this functionality this week.
This change is finally in r300882.


https://reviews.llvm.org/D31604