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4 Commits

Author SHA1 Message Date
Jeremy Morse 6531a78ac4 Revert "[DebugInfo] Remove some users of DBG_VALUEs IsIndirect field"
This reverts commit ed29dbaafa.

I'm backing out D68945, which as the discussion for D73526 shows, doesn't
seem to handle the -O0 path through the codegen backend correctly. I'll
reland the patch when a fix is worked out, apologies for all the churn.
The two parent commits are part of this revert too.

Conflicts:
	llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
	llvm/test/DebugInfo/X86/dbg-addr-dse.ll

SelectionDAGBuilder conflict is due to a nearby change in e39e2b4a79
that's technically unrelated. dbg-addr-dse.ll conflicted because
41206b61e3 (legitimately) changes the order of two lines.

There are further modifications to dbg-value-func-arg.ll: it landed after
the patch being reverted, and I've converted indirection to be represented
by the isIndirect field rather than DW_OP_deref.
2020-02-06 14:41:40 +00:00
Jeremy Morse ed29dbaafa [DebugInfo] Remove some users of DBG_VALUEs IsIndirect field
This patch kills off a significant user of the "IsIndirect" field of
DBG_VALUE machine insts. Brought up in in PR41675, IsIndirect is
techncally redundant as it can be expressed by the DIExpression of a
DBG_VALUE inst, and it isn't helpful to have two ways of expressing
things.

Rather than setting IsIndirect, have DBG_VALUE creators add an extra deref
to the insts DIExpression. There should now be no appearences of
IsIndirect=True from isel down to LiveDebugVariables / VirtRegRewriter,
which is ensured by an assertion in LDVImpl::handleDebugValue. This means
we also get to delete the IsIndirect handling in LiveDebugVariables. Tests
can be upgraded by for example swapping the following IsIndirect=True
DBG_VALUE:

  DBG_VALUE $somereg, 0, !123, !DIExpression(DW_OP_foo)

With one where the indirection is in the DIExpression, by _appending_
a deref:

  DBG_VALUE $somereg, $noreg, !123, !DIExpression(DW_OP_foo, DW_OP_deref)

Which both mean the same thing. 

Most of the test changes in this patch are updates of that form; also some
changes in how the textual assembly printer handles these insts.

Differential Revision: https://reviews.llvm.org/D68945

llvm-svn: 374877
2019-10-15 10:46:24 +00:00
Matthias Braun a83403892a MachineOperand/MIParser: Do not print debug-use flag, infer it
The debug-use flag must be set exactly for uses on DBG_VALUEs.  This is
so obvious that it can be trivially inferred while parsing. This will
reduce noise when printing while omitting an information that has little
value to the user.

The parser will keep recognizing the flag for compatibility with old
`.mir` files.

Differential Revision: https://reviews.llvm.org/D53903

llvm-svn: 345671
2018-10-30 23:28:27 +00:00
Josh Stone f446facab0 [GlobalISel] Lower dbg.declare into indirect DBG_VALUE
Summary:
D31439 changed the semantics of dbg.declare to take the address of a
variable as the first argument, making it indirect.  It specifically
updated FastISel for this change here:

https://reviews.llvm.org/D31439#change-WVArzi177jPl

GlobalISel needs to follow suit, or else it will be missing a level of
indirection in the generated debuginfo.  This problem was seen in a Rust
debuginfo test on aarch64, since GlobalISel is used at -O0 for aarch64.

https://github.com/rust-lang/rust/issues/49807
https://bugzilla.redhat.com/show_bug.cgi?id=1611597
https://bugzilla.redhat.com/show_bug.cgi?id=1625768

Reviewers: dblaikie, aprantl, t.p.northover, javed.absar, rnk

Reviewed By: rnk

Subscribers: #debug-info, rovka, kristof.beyls, JDevlieghere, llvm-commits, tstellar

Differential Revision: https://reviews.llvm.org/D51749

llvm-svn: 341969
2018-09-11 17:52:01 +00:00