This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.
llvm-svn: 252282
This adds the EH_RESTORE x86 pseudo instr, which is responsible for
restoring the stack pointers: EBP and ESP, and ESI if stack realignment
is involved. We only need this on 32-bit x86, because on x64 the runtime
restores CSRs for us.
Previously we had to keep the CATCHRET instruction around during SEH so
that we could convince X86FrameLowering to restore our frame pointers.
Now we can split these instructions earlier.
This was confusing, because we had a return instruction which wasn't
really a return and was ultimately going to be removed by
X86FrameLowering. This change also simplifies X86FrameLowering, which
really shouldn't be building new MBBs.
No observable functional change currently, but with the new register
mask stuff in D14407, CATCHRET will become a register allocator barrier,
and our existing tests rely on us having reasonable register allocation
around SEH.
llvm-svn: 252266
Windows EH funclets need to always return to a single parent funclet. However, it is possible for earlier optimizations to combine funclets (probably based on one funclet having an unreachable terminator) in such a way that this condition is violated.
These changes add code to the WinEHPrepare pass to detect situations where a funclet has multiple parents and clone such funclets, fixing up the unwind and catch return edges so that each copy of the funclet returns to the correct parent funclet.
Differential Revision: http://reviews.llvm.org/D13274?id=39098
llvm-svn: 252249
Summary:
We frequently run bugpoint on a linked module that consists of all
modules we create while jitting the julia standard library. This module
has a very large number of compile units (10000+) in `llvm.dbg.cu`,
which didn't get reduced at all, requiring manual post processing.
This is an attempt to have bugpoint go through and attempt to reduce
the number of global named metadata nodes as well as their operands,
to cut down the number of roots for such metadata.
Reviewers: dexonsmith, reames, pete
Subscribers: pete, dexonsmith, reames, llvm-commits
Differential Revision: http://reviews.llvm.org/D14043
llvm-svn: 252247
The bug: I missed adding break statements in the switch / case.
Original commit message:
[SCEV] Teach SCEV some axioms about non-wrapping arithmetic
Summary:
- A s< (A + C)<nsw> if C > 0
- A s<= (A + C)<nsw> if C >= 0
- (A + C)<nsw> s< A if C < 0
- (A + C)<nsw> s<= A if C <= 0
Right now `C` needs to be a constant, but we can later generalize it to
be a non-constant if needed.
Reviewers: atrick, hfinkel, reames, nlewycky
Subscribers: sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D13686
llvm-svn: 252236
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
llvm-svn: 252219
inalloca variables were not treated as static allocas, therefore didn't
participate in regular stack instrumentation. We don't want them to
participate in dynamic alloca instrumentation as well.
llvm-svn: 252213
We already had a test for this for 32-bit SEH catchpads, but those don't
actually create funclets. We had a bug that only appeared in funclet
prologues, where we would establish EBP and ESI as our FP and BP, and
then downstream prologue code would overwrite them.
While I was at it, I fixed Win64+funclets+stackrealign. This issue
doesn't come up as often there due to the ABI requring 16 byte stack
alignment, but now we can rest easy that AVX and WinEH will work well
together =P.
llvm-svn: 252210
Mangling type information into MachineInstr opcode names was a temporary
measure, and it's starting to get hairy. At the same time, the MC instruction
printer wants to use AsmString strings for printing. This patch takes the
first step, starting the process of adding AsmStrings for instructions.
llvm-svn: 252203
Also, remove an enum hack where enum values were used as indexes into an array.
We may want to make this a real class to allow pattern-based queries/customization (D13417).
llvm-svn: 252196
The needed lld matching changes to be submitted immediately next,
but this revision will cause lld failures with this alone which is expected.
This removes the eating of the error in Archive::Child::getSize() when the characters
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
These changes will require corresponding changes to the lld project. That will be
committed immediately after this change. But this revision will cause lld failures
with this alone which is expected.
llvm-svn: 252192
Summary:
This review is related to another review request http://reviews.llvm.org/D11268, does the same and merely fixes a couple of issues with it.
D11268 is quite old and has merge conflicts against the current trunk.
This request
- rebases D11268 onto the new trunk;
- resolves the merge conflicts;
- fixes the prologue_end tests, which do not pass due to the subprogram definitions not marked as distinct.
Reviewers: echristo, rengolin, kubabrecka
Subscribers: aemerson, rengolin, jyknight, dsanders, llvm-commits, asl
Differential Revision: http://reviews.llvm.org/D14338
llvm-svn: 252177
This fixes the issue of wrong CFA calculation in the following case:
0x08048400 <+0>: push %ebx
0x08048401 <+1>: sub $0x8,%esp
0x08048404 <+4>: **call 0x8048409 <test+9>**
0x08048409 <+9>: **pop %eax**
0x0804840a <+10>: add $0x1bf7,%eax
0x08048410 <+16>: mov %eax,%ebx
0x08048412 <+18>: call 0x80483f0 <bar>
0x08048417 <+23>: add $0x8,%esp
0x0804841a <+26>: pop %ebx
0x0804841b <+27>: ret
The highlighted instructions are a product of movpc instruction. The call
instruction changes the stack pointer, and pop instruction restores its
value. However, the rule for computing CFA is not updated and is wrong on
the pop instruction. So, e.g. backtrace in gdb does not work when on the pop
instruction. This adds cfi instructions for both call and pop instructions.
cfi_adjust_cfa_offset** instruction is used with the appropriate offset for
setting the rules to calculate CFA correctly.
Patch by Violeta Vukobrat.
Differential Revision: http://reviews.llvm.org/D14021
llvm-svn: 252176
We can conservatively know that CMOV's known bits are the intersection of known bits for each of its operands. This helps PerformCMOVToBFICombine find more opportunities.
I tried hard to create a testcase for this and failed - we have to sufficiently confuse DAG.computeKnownBits which can see through all the cheap tricks I tried to narrow my larger testcase down :(
This code is actually exercised in CodeGen/ARM/bfi.ll, there's just no functional difference because DAG.computeKnownBits gets the right answer in that case.
llvm-svn: 252168
We were correctly skipping dbginfo intrinsics and terminators, but the initial bailout wasn't, causing it to bail out on almost any block.
llvm-svn: 252152
