We were hitting an assertion because we were computing smaller type sizes for
instructions that cannot be demoted. The fix first determines the instructions
that will be demoted, and then applies the smaller type size to only those
instructions.
This should fix PR26239.
llvm-svn: 258705
Instructions can be DCE'd after the RegStackify pass. If the instruction which
would be the pop for what would be a push is removed, don't use a push.
llvm-svn: 258694
When generating calls to memcpy, memmove, and memset, use void* as the return
type rather than void, to match the standard signatures for these functions.
This has no practical effect for most targets, since the return values of
these calls aren't being used anyway, and most calling conventions tolerate
this kind of mismatch. However, this change will help support future
optimizations to utilize the return value to avoid holding the argument
value live across a call.
llvm-svn: 258691
The computation of ICmp demanded bits is independent of the individual operand being evaluated. We simply return a mask consisting of the minimum leading zeroes of both operands.
We were incorrectly passing "I" to ComputeKnownBits - this should be "UserI->getOperand(0)". In cases where we were evaluating the 1th operand, we were taking the minimum leading zeroes of it and itself.
This should fix PR26266.
llvm-svn: 258690
This patch was originally committed as r257885, but was reverted due to windows
failures. The cause of these failures has been fixed under r258677, hence
re-committing the original patch.
llvm-svn: 258683
This patch was originally committed as r257884, but was reverted due to windows
failures. The cause of these failures has been fixed under r258677, hence
re-committing the original patch.
llvm-svn: 258682
This patch was originally committed as r257883, but was reverted due to windows
failures. The cause of these failures has been fixed under r258677, hence
re-committing the original patch.
llvm-svn: 258681
VPMADD52LUQ - Packed Multiply of Unsigned 52-bit Integers and Add the Low 52-bit Products to Qword Accumulators
VPMADD52HUQ - Packed Multiply of Unsigned 52-bit Unsigned Integers and Add High 52-bit Products to 64-bit Accumulators
Differential Revision: http://reviews.llvm.org/D16407
llvm-svn: 258680
This was originally committed as r255762, but reverted as it broke windows
bots. Re-commitiing the exact same patch, as the underlying cause was fixed by
r258677.
ARMv8.2-A adds 16-bit floating point versions of all existing VFP
floating-point instructions. This is an optional extension, so all of
these instructions require the FeatureFullFP16 subtarget feature.
The assembly for these instructions uses S registers (AArch32 does not
have H registers), but the instructions have ".f16" type specifiers
rather than ".f32" or ".f64". The top 16 bits of each source register
are ignored, and the top 16 bits of the destination register are set to
zero.
These instructions are mostly the same as the 32- and 64-bit versions,
but they use coprocessor 9 rather than 10 and 11.
Two new instructions, VMOVX and VINS, have been added to allow packing
and extracting two 16-bit floats stored in the top and bottom halves of
an S register.
New fixup kinds have been added for the PC-relative load and store
instructions, but no ELF relocations have been added as they have a
range of 512 bytes.
Differential Revision: http://reviews.llvm.org/D15038
llvm-svn: 258678
Use AVX1 FP instructions (vmaskmovps/pd) in place of the AVX2 int instructions (vpmaskmovd/q).
Differential Revision: http://reviews.llvm.org/D16528
llvm-svn: 258675
Changes in X86.td:
I set features of Intel processors in incremental form: IVB = SNB + X HSW = IVB + X ..
I added Skylake client processor and defined it's features
FeatureADX was missing on KNL
Added some new features to appropriate processors SMAP, IFMA, PREFETCHWT1, VMFUNC and others
Differential Revision: http://reviews.llvm.org/D16357
llvm-svn: 258659
A cleanup can have paths which unwind or end up in unreachable.
If there is an unreachable path *and* a path which unwinds to caller,
we would mistakenly inject an unwind path to a catchswitch on the
unreachable path. This results in a verifier assertion firing because
the cleanup unwinds to two different places: to the caller and to the
catchswitch.
This occured because we used getCleanupRetUnwindDest to determine if the
cleanuppad had no cleanuprets.
This is incorrect, getCleanupRetUnwindDest returns null for cleanuprets
which unwind to caller.
llvm-svn: 258651
Summary:
Previously, we would just output "foo = bar" in the assembly, and then
ptxas would choke. Now we die before emitting any invalid code.
Reviewers: echristo
Subscribers: jholewinski, llvm-commits, jhen, tra
Differential Revision: http://reviews.llvm.org/D16490
llvm-svn: 258638
For the moment, this file takes way too long to run (see inline comments), but
that should be a temporary problem. The fact that the compile time is so slow
for a target that doesn't support maskmov may be a bug worth investigating too.
llvm-svn: 258629
If the INSERTPS zeroes out all the referenced elements from either of the 2 input vectors (and the input is not already UNDEF), then set that input to UNDEF to reduce dependencies.
llvm-svn: 258622
Some of the conditions necessary to produce ccmp sequences were only
checked in recursive calls to emitConjunctionDisjunctionTree() after
some of the earlier expressions were already built. Move all checks over
to isConjunctionDisjunctionTree() so they are all checked before we
start emitting instructions.
Also rename some variable to better reflect their usage.
llvm-svn: 258605
Cleanups in C++ are a little weird. They are only guaranteed to be
reliably executed if, and only if, there is a viable catch handler which
can handle the exception.
This means that reachability of a cleanup is lexically determined by it
being nested with a try-block which unwinds to a catch. It is *cannot*
be reasoned about by examining the control flow edges leaving a cleanup.
Usually this is not a problem. It becomes a problem when there are *no*
edges out of a cleanup because we believed that code post-dominated by
the cleanup is dead. In LLVM's case, this code is what informs the
personality routine about the presence of a suitable catch handler.
However, the lack of edges to that catch handler makes the handler
become unreachable which causes us to remove it. By removing the
handler, the cleanup becomes unreachable.
Instead, inject a catch-all handler with every cleanup that has no
unwind edges. This will allow us to properly unwind the stack.
This fixes PR25997.
llvm-svn: 258580
in MachOObjectFile::getSymbolByIndex() when a Mach-O file has
a symbol table load command but the number of symbols are zero.
The code in MachOObjectFile::symbol_begin_impl() should not be
assuming there is a symbol at index 0, in cases there is no symbol
table load command or the count of symbol is zero. So I also fixed
that. And needed to fix MachOObjectFile::symbol_end_impl() to
also do the same thing for no symbol table or one with zero entries.
The code in MachOObjectFile::getSymbolByIndex() should trigger
the report_fatal_error() for programmatic errors for any index when
there is no symbol table load command and not return the end iterator.
So also fixed that. Note there is no test case as this is a programmatic
error.
The test case using the file macho-invalid-bad-symbol-index has
a symbol table load command with its number of symbols (nsyms)
is zero. Which was incorrectly testing the bad triggering of the
report_fatal_error() in in MachOObjectFile::getSymbolByIndex().
This test case is an invalid Mach-O file but not for that reason.
It appears this Mach-O file use to have an nsyms value of 11,
and what makes this Mach-O file invalid is the counts and
indexes into the symbol table of the dynamic load command
are now invalid because the number of symbol table entries
(nsyms) is now zero. Which can be seen with the existing
llvm-obdump:
% llvm-objdump -private-headers macho-invalid-bad-symbol-index
…
Load command 4
cmd LC_SYMTAB
cmdsize 24
symoff 4216
nsyms 0
stroff 4392
strsize 144
Load command 5
cmd LC_DYSYMTAB
cmdsize 80
ilocalsym 0
nlocalsym 8 (past the end of the symbol table)
iextdefsym 8 (greater than the number of symbols)
nextdefsym 2 (past the end of the symbol table)
iundefsym 10 (greater than the number of symbols)
nundefsym 1 (past the end of the symbol table)
...
And the native darwin tools generates an error for this file:
% nm macho-invalid-bad-symbol-index
nm: object: macho-invalid-bad-symbol-index truncated or malformed object (ilocalsym plus nlocalsym in LC_DYSYMTAB load command extends past the end of the symbol table)
I added new checks for the indexes and sizes for these in the
constructor of MachOObjectFile. And added comments for what
would be a proper diagnostic messages.
And changed the test case using macho-invalid-bad-symbol-index
to test for the new error now produced.
Also added a test with a valid Mach-O file with a symbol table
load command where the number of symbols is zero that shows
the report_fatal_error() is not called.
llvm-svn: 258576
The intrinsic target prefix should match the target name
as it appears in the triple.
This is not yet complete, but gets most of the important ones.
llvm.AMDGPU.* intrinsics used by mesa and libclc are still handled
for compatability for now.
llvm-svn: 258557
Summary:
Make sure that any new and optimized objects created during GlobalOPT copy all the attributes from the base object.
A good example of improper behavior in the current implementation is section information associated with the GlobalObject. If a section was set for it, and GlobalOpt is creating/modifying a new object based on this one (often copying the original name), without this change new object will be placed in a default section, resulting in inappropriate properties of the new variable.
The argument here is that if customer specified a section for a variable, any changes to it that compiler does should not cause it to change that section allocation.
Moreover, any other properties worth representation in copyAttributesFrom() should also be propagated.
Reviewers: jmolloy, joker-eph, joker.eph
Subscribers: slarin, joker.eph, rafael, tobiasvk, llvm-commits
Differential Revision: http://reviews.llvm.org/D16074
llvm-svn: 258556
Summary:
This change adds a `-spp-no-statepoints` flag to PlaceSafepoints that
bypasses the code that wraps newly introduced polls and existing calls
in gc.statepoint. With `-spp-no-statepoints` enabled, PlaceSafepoints
effectively becomes a safpeoint **poll** insertion pass.
The eventual goal is to "constant fold" this option, along with
`-rs4gc-use-deopt-bundles` to `true`, once clients using gc.statepoint
are okay doing so.
Reviewers: pgavlin, reames, JosephTremoulet
Subscribers: sanjoy, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16439
llvm-svn: 258551
The promote alloca pass didn't handle these intrinsics and crashed.
These intrinsics should accept any address space, but for now just
erase them to avoid breaking.
llvm-svn: 258537
The current behavior is incorrect, as the two CCs returned by
changeFPCCToAArch64CC, intended to be OR'ed, are instead used
in an AND ccmp chain.
Consider:
define i32 @t(float %a, float %b, float %c, float %d, i32 %e, i32 %f) {
%cc1 = fcmp one float %a, %b
%cc2 = fcmp olt float %c, %d
%and = and i1 %cc1, %cc2
%r = select i1 %and, i32 %e, i32 %f
ret i32 %r
}
Assuming (%a < %b) and (%c < %d); we used to do:
fcmp s0, s1 # nzcv <- 1000
orr w8, wzr, #0x1 # w8 <- 1
csel w9, w8, wzr, mi # w9 <- 1
csel w8, w8, w9, gt # w8 <- 1
fcmp s2, s3 # nzcv <- 1000
cset w9, mi # w9 <- 1
tst w8, w9 # (w8 & w9) == 1, so: nzcv <- 0000
csel w0, w0, w1, ne # w0 <- w0
We now do:
fcmp s2, s3 # nzcv <- 1000
fccmp s0, s1, #0, mi # mi, so: nzcv <- 1000
fccmp s0, s1, #8, le # !le, so: nzcv <- 1000
csel w0, w0, w1, pl # !pl, so: w0 <- w1
In other words, we transformed:
(c < d) && ((a < b) || (a > b))
into:
(c < d) && (a u>= b) && (a u<= b)
whereas, per De Morgan's, we wanted:
(c < d) && !((a u>= b) && (a u<= b))
Note that this problem doesn't occur in the test-suite.
changeFPCCToAArch64CC produces disjunct CCs; here, one -> mi/gt.
We can't represent that in the fccmp chain; it can't express
arbitrary OR sequences, as one comment explains:
In general we can create code for arbitrary "... (and (and A B) C)"
sequences. We can also implement some "or" expressions, because
"(or A B)" is equivalent to "not (and (not A) (not B))" and we can
implement some negation operations. [...] However there is no way
to negate the result of a partial sequence.
Instead, introduce changeFPCCToANDAArch64CC, which produces the
conjunct cond codes:
- (a one b)
== ((a olt b) || (a ogt b))
== ((a ord b) && (a une b))
- (a ueq b)
== ((a uno b) || (a oeq b))
== ((a ule b) && (a uge b))
Note that, at first, one might think that, when PushNegate is true,
we should use the disjunct CCs, in effect doing:
(a || b)
= !(!a && !(b))
= !(!a && !(b1 || b2)) <- changeFPCCToAArch64CC(b, b1, b2)
= !(!a && !b1 && !b2)
However, we can take advantage of the fact that the CC is already
negated, which lets us avoid special-casing PushNegate and doing
the simpler to reason about:
(a || b)
= !(!a && (!b))
= !(!a && (b1 && b2)) <- changeFPCCToANDAArch64CC(!b, b1, b2)
= !(!a && b1 && b2)
This makes both emitConditionalCompare cases behave identically,
and produces correct ccmp sequences for the 2-CC fcmps.
llvm-svn: 258533
but to return object_error::parse_failed. Then made the code in llvm-nm
do for Mach-O files what is done in the darwin native tools which is to
print "bad string index" for bad string indexes. Updated the error message
in the llvm-objdump test, and added tests to show llvm-nm prints
"bad string index" and a test to print the actual bad string index value
which in this case is 0xfe000002 when printing the fields as raw hex.
llvm-svn: 258520
This reapplies r258296 and r258366, and also fixes an existing bug in
SelectionDAG.cpp's isMemSrcFromString, neglecting to account for the
offset in a GlobalAddressSDNode, which is uncovered by those patches.
llvm-svn: 258482
Summary:
SETCC with f16 vectors has OperationAction set to Expand but still gets
lowered to FCM* intrinsics based on its result type. This patch skips
lowering of VSETCC if the operand is an f16 vector.
v4 and v8 tests included.
Reviewers: ab, jmolloy
Subscribers: srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D15361
llvm-svn: 258471
This reverts r258296 and the follow up r258366. With this change, we
miscompiled the following program on Windows:
#include <string>
#include <iostream>
static const char kData[] = "asdf jkl;";
int main() {
std::string s(kData + 3, sizeof(kData) - 3);
std::cout << s << '\n';
}
llvm-svn: 258465
The X86 musttail implementation finds register parameters to forward by
running the calling convention algorithm until a non-register location
is returned. However, assigning a vector memory location has the side
effect of increasing the function's stack alignment. We shouldn't
increase the stack alignment when we are only looking for register
parameters, so this change conditionalizes it.
llvm-svn: 258442
Better handling of the annoying pshuflw/pshufhw ops which only shuffle lower/upper halves of a vector.
Added vXi16 unary shuffle support for cases where i16 elements (from the same half of the source) are being splatted to the whole of one of the halves. This avoids the general lowering case which must shuffle the 32-bit elements first - meaning that we used to end up with unnecessary duplicate pshuflw/pshufhw shuffles.
Note this has the side effect of a lot of SSSE3 test cases no longer needing to use PSHUFB, as it falls below the 3 op combine threshold for when PSHUFB is typically worth it. I've raised PR26183 to discuss if the threshold should be changed and whether we need to make it more specific to the target CPU.
Differential Revision: http://reviews.llvm.org/D14901
llvm-svn: 258440
but to return object_error::parse_failed. Then made the code in llvm-nm
do for Mach-O files what is done in the darwin native tools which is to
print "(?,?)" or just "s" for bad section indexes. Also added a test to show
it prints the bad section index of "42" when printing the fields as raw hex.
llvm-svn: 258434
This is similar to the bug/fix:
https://llvm.org/bugs/show_bug.cgi?id=26211http://reviews.llvm.org/rL258325
The fmin() test case reveals another bug caused by sloppy
code duplication. It will crash without this patch because
fp128 is a valid floating-point type, but we would think
that we had matched a function that used doubles.
The new helper function can be used to replace similar
checks that are used in several other places in this file.
llvm-svn: 258428
This commit extends the patterns recognised by InstSimplify to also handle (x >> y) <= x in the same way as (x /u y) <= x.
The missing optimisation was found investigating why LLVM did not optimise away bound checks in a binary search: https://github.com/rust-lang/rust/pull/30917
Patch by Andrea Canciani!
Differential Revision: http://reviews.llvm.org/D16402
llvm-svn: 258422
This patch adds the instrumentation for indirect call value profiling. It finds all the indirect call-sites and generates instrprof_value_profile intrinsic calls. A new opt level option -disable-vp is introduced to disable this instrumentation.
Reviewers: davidxl, betulb, vsk
Differential Revision: http://reviews.llvm.org/D16016
llvm-svn: 258417
Do not emit profile arc files and note files for module and skeleton
CU's.
Our users report seeing unexpected *.gcda and *.gcno files in their
projects when using gcov-style profiling with modules or frameworks.
The unwanted files come from these modules. This is not very helpful
for end-users. Further, we've seen reports of instrumented programs
crashing while writing these files out (due to I/O failures).
rdar://problem/22838296
Reviewed-by: aprantl
Differential Revision: http://reviews.llvm.org/D15997
llvm-svn: 258406
This change attempts to produce vectorized integer expressions in bit widths
that are narrower than their scalar counterparts. The need for demotion arises
especially on architectures in which the small integer types (e.g., i8 and i16)
are not legal for scalar operations but can still be used in vectors. Like
similar work done within the loop vectorizer, we rely on InstCombine to perform
the actual type-shrinking. We use the DemandedBits analysis and
ComputeNumSignBits from ValueTracking to determine the minimum required bit
width of an expression.
Differential revision: http://reviews.llvm.org/D15815
llvm-svn: 258404
Summary:
This is now the same as the behaviour of the GNU assembler. This was done
as it is required in order to build the Linux kernel with the integrated
assembler enabled.
Reviewers: dsanders, vkalintiris
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13594
llvm-svn: 258400
There's an overloading of the "movsd" and "cmpsd" instructions, e.g. movsd can be either "Move Data from String to String" or "Move or Merge Scalar Double-Precision Floating-Point Value".
The former should produce warnings when parsing a memory operand that is not ESI/EDI, but the latter should not.
Fixed the code to produce warnings only after making sure we're dealing with the first case.
Expanded the tests of the produced warnings + fixed RUN line of the test so that it would check both stdout and stderr
Differential Revision: http://reviews.llvm.org/D16359
llvm-svn: 258393
The binary contains two (merged) covmap sections which
have duplicate CovMapRecords from comdat (template instantation).
This test makes sure the reader reads it properly. It also
tests that the coverage data from different instantiations
of the same template function are properly merged in show
output.
llvm-svn: 258376
Fix the condition for when the new global takes over the name of
the existing one to be the negation of the condition for the new
global to get internal linkage.
llvm-svn: 258355
Summary:
While working on uniform branching, I've hit a few cases where we emit
i1 SETCC operations.
Reviewers: arsenm
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D16233
llvm-svn: 258352
Summary:
This adds a new kind of operand bundle to LLVM denoted by the
`"gc-transition"` tag. Inputs to `"gc-transition"` operand bundle are
lowered into the "transition args" section of `gc.statepoint` by
`RewriteStatepointsForGC`.
This removes the last bit of functionality that was unsupported in the
deopt bundle based code path in `RewriteStatepointsForGC`.
Reviewers: pgavlin, JosephTremoulet, reames
Subscribers: sanjoy, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16342
llvm-svn: 258338
Some architecture specific ELF section flags might have the same value
(for example SHF_X86_64_LARGE and SHF_HEX_GPREL) and we have to check
machine architectures to select an appropriate set of possible flags.
The patch selects architecture specific flags into separate arrays
`ElfxxxSectionFlags` and combines `ElfSectionFlags` and `ElfxxxSectionFlags`
before pass to the `StreamWriter::printFlags()` method.
Differential Revision: http://reviews.llvm.org/D16269
llvm-svn: 258334
The selection process being split into separate passes, we need generic opcodes
to translate the LLVM IR to target independent code.
This patch adds an opcode for addition: G_ADD.
Differential Revision: http://reviews.llvm.org/D15472
llvm-svn: 258333
When a symbol S shows up in an expression in assembly there are two
possible interpretations
* The expression is referring to the value of S in this file.
* The expression is referring to the value after symbol resolution.
In the first case the assembler can reason about the value and try to
produce a relocation.
In the second case, that is only possible if the symbol cannot be
preempted.
Assemblers are not very consistent about which interpretation gets used.
This changes MC to agree with GAS in the case of an expression of the
form "Sym - WeakSym".
llvm-svn: 258329
The test case will crash without this patch because the subsequent call to
hasUnsafeAlgebra() assumes that the call instruction is an FPMathOperator
(ie, returns an FP type).
This part of the function signature check was omitted for the sqrt() case,
but seems to be in place for all other transforms.
Before:
http://reviews.llvm.org/rL257400
...we would have needlessly continued execution in optimizeSqrt(), but the
bug was harmless because we'd eventually fail some other check and return
without damage.
This should fix:
https://llvm.org/bugs/show_bug.cgi?id=26211
Differential Revision: http://reviews.llvm.org/D16198
llvm-svn: 258325
There was support for writing the AArch64 big endian data fixup entries in
the .eh_frame section in BE. This is changed to write all such fixup
entries in BE with no restriction on the section. This is similar to
the existing support for fixup entries for ARM.
A test is added to check the length field in the .debug_line section as
this is an example of where such a fixup occurs.
Differential Revision: http://reviews.llvm.org/D16064
llvm-svn: 258320
If converter was somewhat careless about "diamond" cases, where there
was no join block, or in other words, where the true/false blocks did
not have analyzable branches. In such cases, it was possible for it to
remove (needed) branches, resulting in a loss of entire basic blocks.
Differential Revision: http://reviews.llvm.org/D16156
llvm-svn: 258310
The AArch64 .inst directive was implemented using EmitIntValue, which resulted
in both $x and $d (code and data) mapping symbols being emitted at the same
address. This fixes it to only emit the $x mapping symbol.
EmitIntValue also emits the value in big-endian order when targeting big-endian
systems, but instructions are always emitted in little-endian order for
AArch64.
Differential Revision: http://reviews.llvm.org/D16349
llvm-svn: 258308
SelectionDAG previously missed opportunities to fold constants into
GlobalAddresses in several areas. For example, given `(add (add GA, c1), y)`, it
would often reassociate to `(add (add GA, y), c1)`, missing the opportunity to
create `(add GA+c, y)`. This isn't often visible on targets such as X86 which
effectively reassociate adds in their complex address-mode folding logic,
however it is currently visible on WebAssembly since it currently has very
simple address mode folding code that doesn't reassociate anything.
This patch fixes this by making SelectionDAG fold offsets into GlobalAddresses
at the same times that it folds constants together, so that it doesn't miss any
opportunities to perform such folding.
Differential Revision: http://reviews.llvm.org/D16090
llvm-svn: 258296
Summary:
Funclet EH tables require that a given funclet have only one unwind
destination for exceptional exits. The verifier will therefore reject
e.g. two cleanuprets with different unwind dests for the same cleanup, or
two invokes exiting the same funclet but to different unwind dests.
Because catchswitch has no 'nounwind' variant, and because IR producers
are not *required* to annotate calls which will not unwind as 'nounwind',
it is legal to nest a call or an "unwind to caller" catchswitch within a
funclet pad that has an unwind destination other than caller; it is
undefined behavior for such a call or catchswitch to unwind.
Normally when inlining an invoke, calls in the inlined sequence are
rewritten to invokes that unwind to the callsite invoke's unwind
destination, and "unwind to caller" catchswitches in the inlined sequence
are rewritten to unwind to the callsite invoke's unwind destination.
However, if such a call or "unwind to caller" catchswitch is located in a
callee funclet that has another exceptional exit with an unwind
destination within the callee, applying the normal transformation would
give that callee funclet multiple unwind destinations for its exceptional
exits. There would be no way for EH table generation to determine which
is the "true" exit, and the verifier would reject the function
accordingly.
Add logic to the inliner to detect these cases and leave such calls and
"unwind to caller" catchswitches as calls and "unwind to caller"
catchswitches in the inlined sequence.
This fixes PR26147.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: alexcrichton, llvm-commits
Differential Revision: http://reviews.llvm.org/D16319
llvm-svn: 258273
Summary:
This teaches MachineSink to not sink instructions that might break the
implicit null check optimization that runs later. This should not
affect frontends that do not use implicit null checks.
Reviewers: aadg, reames, hfinkel, atrick
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D14632
llvm-svn: 258254
calling convention.
The implementation of the related callbacks in the x86 backend for such
functions are not ready to deal with a prologue block that is not the entry
block of the function.
This fixes PR26107, but the longer term solution would be to fix those callbacks.
llvm-svn: 258221