Here is a theoretical example that illustrates why the placement is important.
tmp1 =
store tmp1 -> x
...
tmp2 = add ...
...
call
...
store tmp2 -> x
Now mem2reg comes along:
tmp1 =
dbg_value (tmp1 -> x)
...
tmp2 = add ...
...
call
...
dbg_value (tmp2 -> x)
When the debugger examine the value of x after the add instruction but before the call, it should have the value of tmp1.
Furthermore, for dbg_value's that reference constants, they should not be emitted at the beginning of the block (since they do not have "producers").
This patch also cleans up how SDISel manages DbgValue nodes. It allow a SDNode to be referenced by multiple SDDbgValue nodes. When a SDNode is deleted, it uses the information to find the SDDbgValues and invalidate them. They are not deleted until the corresponding SelectionDAG is destroyed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99469 91177308-0d34-0410-b5e6-96231b3b80d8
--- Reverse-merging r99440 into '.':
U test/MC/AsmParser/X86/x86_32-bit_cat.s
U test/MC/AsmParser/X86/x86_32-encoding.s
U include/llvm/IntrinsicsX86.td
U include/llvm/CodeGen/SelectionDAGNodes.h
U lib/Target/X86/X86InstrSSE.td
U lib/Target/X86/X86ISelLowering.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99450 91177308-0d34-0410-b5e6-96231b3b80d8
disabled for several months (since svn r88806) and no one noticed. My fix
for pr6543 yesterday reenabled it, but broke the ARM port's code for using
TBB/TBH. Rather than adding a target hook to disable merging for Thumb2 only,
I'm just taking this out. It is not common to have identical jump tables,
the code we used to merge them was O(N^2), and it only helps code size, not
performance.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98977 91177308-0d34-0410-b5e6-96231b3b80d8
always create a new jump table. The intention was to avoid merging jump
tables in SelectionDAGBuilder, and to wait for the branch folding pass to
merge tables. Unfortunately, the same getJumpTableIndex() method is also
used to merge tables in branch folding, so as a result of this change
branch tables are never merged. Worse, the branch folding code is expecting
getJumpTableIndex to always return the index of an existing table, but with
this change, it never does so. In at least some cases, e.g., pr6543, this
creates references to non-existent tables.
I've fixed the problem by adding a new createJumpTableIndex function, which
will always create a new table, and I've changed getJumpTableIndex to only
look at existing tables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98845 91177308-0d34-0410-b5e6-96231b3b80d8
to LLVM IR changes with addr label weirdness. In the testcase, we
generate references to the two bb's when codegen'ing the first
function:
_test1: ## @test1
leaq Ltmp0(%rip), %rax
..
leaq Ltmp1(%rip), %rax
Then continue to codegen the second function where the blocks
get merged. We're now smart enough to emit both labels, producing
this code:
_test_fun: ## @test_fun
## BB#0: ## %entry
Ltmp1: ## Block address taken
Ltmp0:
## BB#1: ## %ret
movl $-1, %eax
ret
Rejoice.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98595 91177308-0d34-0410-b5e6-96231b3b80d8
label is generated, but then the block is deleted. Since the
value is undefined, we just emit the label right after the entry
label of the function. It might matter that the label is in the
same section as the function was afterall.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98579 91177308-0d34-0410-b5e6-96231b3b80d8
function, then the BB is RAUW'd before the definition is emitted. There
are still two cases not being handled, but this should improve us back to
the situation before I touched anything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98566 91177308-0d34-0410-b5e6-96231b3b80d8
label instead of trying to form one based on the BB name (which
causes collisions if the name is empty). This fixes PR6608
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98495 91177308-0d34-0410-b5e6-96231b3b80d8
an MCSymbol. Make the EH_LABEL MachineInstr hold its label
with an MCSymbol instead of ID. Fix a bug in MMI.cpp which
would return labels named "Label4" instead of "label4".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98463 91177308-0d34-0410-b5e6-96231b3b80d8
instead of label ID's. This cleans up and regularizes a bunch
of code and makes way for future progress.
Unfortunately, this pointed out to me that JITDwarfEmitter.cpp
is largely copy and paste from DwarfException/MachineModuleInfo
and other places. This is very sad and disturbing. :(
One major change here is that TidyLandingPads moved from being
called in DwarfException::BeginFunction to being called in
DwarfException::EndFunction. There should not be any
functionality change from doing this, but I'm not an EH expert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98459 91177308-0d34-0410-b5e6-96231b3b80d8
and passing off ownership to AsmPrinter. Now MachineModuleInfo
creates it and owns it by value. This allows us to use MCSymbols
more consistently throughout the rest of the code generator, and
simplifies a bit of code. This also allows MachineFunction to
keep an MCContext reference handy, and cleans up the TargetRegistry
interfaces for AsmPrinters.
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an MCExpr and not an MCSymbol. Change it to take an MCStreamer,
which is currently unused.
No functionality change.
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cl = EXTRACT_SUBREG reg1024, 1, is overly conservative. It should check
for overlaps of vr's live interval with the super registers of the
physical register (ECX in this case) and let JoinIntervals() handle checking
the coalescing feasibility against the physical register (cl in this case).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98251 91177308-0d34-0410-b5e6-96231b3b80d8
indicates that an MCSymbol is external or not. (It's true if it's external.)
This will be used to specify the correct information to add to non-lazy
pointers. That will be explained further when this bit is used.
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and add a FIXME about how we are eventually going to zap this
lookup table once mc world domination is complete.
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