After some stellar (& inspired) help from Reid Kleckner providing a test
case for some rather unstable undefined behavior showing up as
assertions produced by r214761, I was able to fix this issue in DAE
involving the application of both varargs removal, followed by normal
argument removal.
Indeed I introduced this same bug into ArgumentPromotion (r212128) by
copying the code from DAE, and when I fixed the bug in ArgPromo
(r213805) and commented in that patch that I didn't need to address the
same issue in DAE because it was a single pass. Turns out it's two pass,
one for the varargs and one for the normal arguments, so the same fix is
needed (at least during varargs removal). So here it is.
(the observable/net effect of this bug, even when it didn't result in
assertion failure, is that debug info would describe the DAE'd function
in the abstract, but wouldn't provide high/low_pc, variable locations,
line table, etc (it would appear as though the function had been
entirely optimized away), see the original PR14016 for details of the
general problem)
I'm not recommitting the assertion just yet, as there's been another
regression of it since I last tried. It might just be a few test cases
weren't adequately updated after Adrian or Duncan's recent schema
changes.
llvm-svn: 219210
Summary:
According to the ABI documentation, f128 and {f128} should both be returned
in $f0 and $f2. However, this doesn't match GCC's behaviour which is to
return f128 in $f0 and $f2, but {f128} in $f0 and $f1.
Reviewers: vmedic
Reviewed By: vmedic
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5578
llvm-svn: 219196
Unfortunately, this isn't easy to fix since there's no simple way to figure out from the disassembler tables whether the W-bit is being used to select a 64-bit GPR or if its a required part of the opcode. The fix implemented here just looks for "64" in the instruction name and ignores the W-bit in 32-bit mode if its present.
Fixes PR21169.
llvm-svn: 219194
Most Unix-like operating systems guarantee that the file descriptor is
closed after a call to close(2), even if close comes back with EINTR.
For these systems, calling close _again_ will either do nothing or close
some other file descriptor open(2)'d by another thread. (Linux)
However, some operating systems do not have this behavior. They require
at least another call to close(2) before guaranteeing that the
descriptor is closed. (HP-UX)
And some operating systems have an unpredictable blend of the two
behaviors! (xnu)
Avoid this disaster by blocking all signals before we call close(2).
This ensures that a signal will not be delivered to the thread and
close(2) will not give us back EINTR. We restore the signal mask once
the operation is done.
N.B. This isn't a problem on Windows, it doesn't have a notion of EINTR
because signals always get delivered to dedicated signal handling
threads.
llvm-svn: 219189
The plugin API doesn't have the notion of linkonce, only weak. It is up to the
plugin to figure out if a symbol used only for the symbol table can be dropped.
In particular, it has to avoid dropping a linkonce_odr selected by gold if there
is also a weak_odr.
llvm-svn: 219188
The code already folds sign-/zero-extends, but only if they are arguments to
mul and shift instructions. This extends the code to also fold them when they
are direct inputs.
llvm-svn: 219187
Tiny enhancement to the address computation code to also fold sub instructions
if the rhs is constant and can be folded into the offset.
llvm-svn: 219186
This commit fixes an issue with sign-/zero-extending loads that was discovered
by Richard Barton.
We use now the correct load instructions for sign-extending loads to 64bit. Also
updated and added more unit tests.
llvm-svn: 219185
The call to copyAttributesFrom will copy the visibility, which might assert
if it were to produce something invalid like "internal hidden". We avoid it
by first creating the replacement with the original linkage and then setting
it to internal affter the call to copyAttributesFrom.
llvm-svn: 219184
When creating an internal function replacement for use in an alias we were
not remapping the argument uses in the instructions to point to the new
arguments.
llvm-svn: 219177
Takes care of the assert that caused build fails.
Rather than asserting the code checks now that the definition
and use are in the same block, and does not attempt
to optimize when that is not the case.
llvm-svn: 219175
It's possible to start a program with one (or all) of the standard file
descriptors closed. Subsequent open system calls will give the program
a low-numbered file descriptor.
This is problematic because we may believe we are writing to standard
out instead of a file.
Introduce Process::FixupStandardFileDescriptors, a helper function to
remap standard file descriptors to /dev/null if they were closed before
the program started.
llvm-svn: 219170
The patch's author points out that, despite the function's documentation,
getSetCCResultType is only used to get the SETCC result type (with one
here-removed problematic exception). In one case, getSetCCResultType was being
used to get the predicate type to use for a SELECT node, and then
SIGN_EXTENDing (or truncating) to get the input predicate to match that type.
Unfortunately, this was happening inside visitSIGN_EXTEND, and creating new
SIGN_EXTEND nodes was causing an infinite loop. In addition, this behavior was
wrong if a target was not using ZeroOrNegativeOneBooleanContent. Lastly, the
extension/truncation seems unnecessary here: SELECT is defined as:
Select(COND, TRUEVAL, FALSEVAL). If the type of the boolean COND is not i1
then the high bits must conform to getBooleanContents.
So here we remove this use of getSetCCResultType and update
getSetCCResultType's documentation to reflect its actual uses.
Patch by deadal nix!
llvm-svn: 219141
This reverts r218944, which reverted r218714, plus a bug fix.
Description of the bug in r218714 (by Nick)
The original patch forgot to check if the Scale in VariableGEPIndex flipped the
sign of the variable. The BasicAA pass iterates over the instructions in the
order they appear in the function, and so BasicAliasAnalysis::aliasGEP is
called with the variable it first comes across as parameter GEP1. Adding a
%reorder label puts the definition of %a after %b so aliasGEP is called with %b
as the first parameter and %a as the second. aliasGEP later calculates that %a
== %b + 1 - %idxprom where %idxprom >= 0 (if %a was passed as the first
parameter it would calculate %b == %a - 1 + %idxprom where %idxprom >= 0) -
ignoring that %idxprom is scaled by -1 here lead the patch to incorrectly
conclude that %a > %b.
Revised patch by Nick White, thanks! Thanks to Lang to isolating the bug.
Slightly modified by me to add an early exit from the loop and avoid
unnecessary, but expensive, function calls.
Original commit message:
Two related things:
1. Fixes a bug when calculating the offset in GetLinearExpression. The code
previously used zext to extend the offset, so negative offsets were converted
to large positive ones.
2. Enhance aliasGEP to deduce that, if the difference between two GEP
allocations is positive and all the variables that govern the offset are also
positive (i.e. the offset is strictly after the higher base pointer), then
locations that fit in the gap between the two base pointers are NoAlias.
Patch by Nick White!
llvm-svn: 219135
Codeview line tables for functions in different sections refer to a common
STRING_TABLE_SUBSECTION for filenames.
This happens when building with -Gy or with inline functions with MSVC.
Original patch by Jeff Muizelaar!
llvm-svn: 219125
We used to return PartialAlias if *either* variable being queried interacted
with arguments or globals. AFAICT, we can change this to only returning
MayAlias iff *both* variables being queried interacted with arguments or
globals.
Also, adding some basic functionality tests: some basic IPA tests, checking
that we give conservative responses with arguments/globals thrown in the mix,
and ensuring that we trace values through stores and loads.
Note that saying that 'x' interacted with arguments or globals means that the
Attributes of the StratifiedSet that 'x' belongs to has any bits set.
Patch by George Burgess IV, thanks!
llvm-svn: 219122
output of the llvm-dwarfdump and llvm-objdump report the endianness
used when the object files were generated.
Patch by Charlie Turner.
llvm-svn: 219110
These will make it easier to test further changes to the
code generation and optimization pipelines as those are
moved to subtargets initialized with target feature and
target cpu.
llvm-svn: 219106
It was just calling a bunch of DwarfUnit functions anyway, as can be
seen by the simplification of removing "TheCU" from all the function
calls in the implementation.
llvm-svn: 219103
David Blaikie