It isn't legal to hoist a load past a call which might not return;
even if it doesn't throw, it could, for example, call exit().
Fixes http://llvm.org/PR27953.
llvm-svn: 272495
Summary:
Make isGuaranteedToExecute use the
isGuaranteedToTransferExecutionToSuccessor helper, and make that helper
a bit more accurate.
There's a potential performance impact here from assuming that arbitrary
calls might not return. This probably has little impact on loads and
stores to a pointer because most things alias analysis can reason about
are dereferenceable anyway. The other impacts, like less aggressive
hoisting of sdiv by a variable and less aggressive hoisting around
volatile memory operations, are unlikely to matter for real code.
This also impacts SCEV, which uses the same helper. It's a minor
improvement there because we can tell that, for example, memcpy always
returns normally. Strictly speaking, it's also introducing
a bug, but it's not any worse than everywhere else we assume readonly
functions terminate.
Fixes http://llvm.org/PR27857.
Reviewers: hfinkel, reames, chandlerc, sanjoy
Subscribers: broune, llvm-commits
Differential Revision: http://reviews.llvm.org/D21167
llvm-svn: 272489
The script now replace '.LCPI888_8' style asm symbols with the {{\.LCPI.*}} re pattern - this helps stop hardcoded symbols in 32-bit x86 tests changing with every edit of the file
Refreshed some tests to demonstrate the new check
llvm-svn: 272488
This is one of the patches to clean up the code so that
it is in a better form to make future enhancements easier.
In htis patch, the logic to collect viable successors are
extrated as a helper to unclutter the caller which gets very
large recenty. Also cleaned up BP adjustment code.
llvm-svn: 272482
Summary:
Dominator updation fails for a loop inserted with a new basicblock.
A block required by DT to set the IDom might not have been cloned yet. This is because there is no predefined ordering of loop blocks (except for the header block which should be the first block in the list).
The patch first creates DT nodes for the cloned blocks and then separately updates the DT in a follow-on loop.
Reviewers: anemet, dberlin
Subscribers: dberlin, llvm-commits
Differential Revision: http://reviews.llvm.org/D20899
llvm-svn: 272479
PSHUFB can speed up BITREVERSE of byte vectors by performing LUT on the low/high nibbles separately and ORing the results. Wider integer vector types are already BSWAP'd beforehand so also make use of this approach.
llvm-svn: 272477
These are byte shift instructions and it will make shuffle combining a lot more straightforward if we can assume a vXi8 vector of bytes so decoded shuffle masks match the return type's number of elements
llvm-svn: 272468
This shouldn't have any functional difference, but it appears to be the
pattern used for other methods on DynamicLibrary, and it should avoid
the -Wpedantic warning on one of the build bots about the direct
reinterpret_cast.
llvm-svn: 272461
MCJIT will now set the DataLayout on a module when it is added to the JIT,
rather than waiting until it is codegen'd, and the runFunction method will
finalize the module containing the function to be run before running it.
The fibonacci example has been updated to include and link against MCJIT.
llvm-svn: 272455
undef uses are no real uses of a register and must be ignored by
findLastUseBefore() so that handleMove() does not produce invalid live
intervals in some cases.
This fixed http://llvm.org/PR28083
llvm-svn: 272446
Summary:
Iterates all (except the first and the last) operands within each GEP
instruction for instrumentation.
Adds test struct_field_gep.ll.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, bruening, llvm-commits
Differential Revision: http://reviews.llvm.org/D21242
llvm-svn: 272442
Summary:
I can't find a case where we can rotate a loop more than once, and it looks
like we never do this. To rotate a loop following conditions should be met:
1) its header should be exiting
2) its latch shouldn't be exiting
But after the first rotation the header becomes the new latch, so this
condition can never be true any longer.
Tested on with an assert on LNT testsuite and make check.
Reviewers: hfinkel, sanjoy
Subscribers: sebpop, sanjoy, llvm-commits, mzolotukhin
Differential Revision: http://reviews.llvm.org/D20181
llvm-svn: 272439
This fixes an alignment issue by forcing all cached allocations
to be 8 byte aligned, and also fixes an issue arising on big
endian systems by writing ulittle32_t's instead of uint32_t's
in the test.
llvm-svn: 272437
A memory access defined on function entry cannot be locally dominated by another memory access.
The patch was split from http://reviews.llvm.org/D19338 which exposes the problem.
Differential Revision: http://reviews.llvm.org/D21039
llvm-svn: 272436
Summary:
When stack-protection is activated and WinEH exceptions is used,
the EHRegNode (exception handling registration) is allocated twice on the stack.
This was not breaking anything except loosing space on the stack.
```
D:\src\llvm\examples>llc exc2.ll -debug-only=pei
alloc FI(0) at SP[-24]
alloc FI(1) at SP[-48] <<-- Allocated
alloc FI(1) at SP[-72] <<-- Allocated twice!?
alloc FI(2) at SP[-76]
alloc FI(4) at SP[-80]
alloc FI(3) at SP[-84]
```
Reviewers: rnk, majnemer
Subscribers: chrisha, llvm-commits
Differential Revision: http://reviews.llvm.org/D21188
llvm-svn: 272426
Loop unswitching may cause MSan false positive when the unswitch
condition is not guaranteed to execute.
This is very similar to ASan and TSan special case in
llvm::isSafeToSpeculativelyExecute (they don't like speculative loads
and stores), but for branch instructions.
This is a workaround for PR28054.
llvm-svn: 272421
Support and generate Compare and Traps like CRT, CIT, etc.
Support Trap as legal DAG opcodes and generate "j .+2" for them by default.
Add support for Conditional Traps and use the If Converter to convert them into
the corresponding compare and trap opcodes.
Differential Revision: http://reviews.llvm.org/D21155
llvm-svn: 272419
Summary:
We need to set the fixup type to FK_Data_4 for the
SCRATCH_RSRC_DWORD[01] symbols, since these require absolute
relocations, and fixup_si_rodata is for relative relocations.
Reviewers: arsenm, kzhuravl
Subscribers: arsenm, kzhuravl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21153
llvm-svn: 272417
