Calls with inalloca are lowered by skipping all stores for arguments
passed in memory and the initial stack adjustment to allocate argument
memory.
Now the frontend is responsible for the memory layout, and the backend
doesn't have to do any work. As a result these changes are pretty
minimal.
Reviewers: echristo
Differential Revision: http://llvm-reviews.chandlerc.com/D2637
llvm-svn: 200596
Allocas marked inalloca are never static, but we were trying to put them
into the static alloca map if they were in the entry block. Also add an
assertion in x86 fastisel.
llvm-svn: 200593
It looks like these pseudos were only used for pattern matching. Def pats are
the appropriate way to do that. As a bonus, these intrinsics will now have
memory operands folded properly, and better FMA3 variants selected where
appropriate (see r199933).
<rdar://problem/15611947>
llvm-svn: 200577
MSVC always places the 'this' parameter for a method first. The
implicit 'sret' pointer for methods always comes second. We already
implement this for __thiscall by putting sret parameters on the stack,
but __cdecl methods require putting both parameters on the stack in
opposite order.
Using a special calling convention allows frontends to keep the sret
parameter first, which avoids breaking lots of assumptions in LLVM and
Clang.
Fixes PR15768 with the corresponding change in Clang.
Reviewers: ributzka, majnemer
Differential Revision: http://llvm-reviews.chandlerc.com/D2663
llvm-svn: 200561
when the input is a concat_vectors and the insert replaces one of the
concat halves:
Lower half: fold (insert_subvector (concat_vectors X, Y), Z) ->
(concat_vectors Z, Y)
Upper half: fold (insert_subvector (concat_vectors X, Y), Z) ->
(concat_vectors X, Z)
This can be seen with the following IR:
define <8 x float> @lower_half(<4 x float> %v1, <4 x float> %v2, <4 x
float> %v3) {
%1 = shufflevector <4 x float> %v1, <4 x float> %v2, <8 x i32> <i32
0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
%2 = tail call <8 x float> @llvm.x86.avx.vinsertf128.ps.256(<8 x
float> %1, <4 x float> %v3, i8 0)
The vinsertf128 intrinsic is converted into an insert_subvector node
in SelectionDAGBuilder.cpp.
Using AVX, without the patch this generates two vinsertf128 instructions:
vinsertf128 $1, %xmm1, %ymm0, %ymm0
vinsertf128 $0, %xmm2, %ymm0, %ymm0
With the patch this is optimized into:
vinsertf128 $1, %xmm1, %ymm2, %ymm0
Patch by Robert Lougher.
llvm-svn: 200506
When converting from "or + br" to two branches, or converting from
"and + br" to two branches, we correctly update the edge weights of
the two branches.
The previous attempt at r200431 was reverted at r200434 because of
two testing case failures. I modified my patch a little, but forgot
to re-run "make check-all".
Testing case CodeGen/ARM/lsr-unfolded-offset.ll is updated because of
the patch's impact on branch probability which causes changes in
spill placement.
llvm-svn: 200502
The SWAP instruction only exists in a 32-bit variant, but the 64-bit
atomic swap can be implemented in terms of CASX, like the other atomic
rmw primitives.
llvm-svn: 200453
When converting from "or + br" to two branches, or converting from
"and + br" to two branches, we correctly update the edge weights of
the two branches.
llvm-svn: 200431
This commit only handles IfConvertTriangle. To update edge weights
of a successor, one interface is added to MachineBasicBlock:
/// Set successor weight of a given iterator.
setSuccWeight(succ_iterator I, uint32_t weight)
An existing testing case test/CodeGen/Thumb2/v8_IT_5.ll is updated,
since we now correctly update the edge weights, the cold block
is placed at the end of the function and we jump to the cold block.
llvm-svn: 200428
After all hard work to implement the EHABI and with the test-suite
passing, it's time to turn it on by default and allow users to
disable it as a work-around while we fix the eventual bugs that show
up.
This commit also remove the -arm-enable-ehabi-descriptors, since we
want the tables to be printed every time the EHABI is turned on
for non-Darwin ARM targets.
Although MCJIT EHABI is not working yet (needs linking with the right
libraries), this commit also fixes some relocations on MCJIT regarding
the EH tables/lib calls, and update some tests to avoid using EH tables
when none are needed.
The EH tests in the test-suite that were previously disabled on ARM
now pass with these changes, so a follow-up commit on the test-suite
will re-enable them.
llvm-svn: 200388
Otherwise, assembler (gas) fails to assemble them with error message "operation
combines symbols in different segments". This is because MC computes
pc_rel entries with subtract expression between labels from different sections.
llvm-svn: 200373
This is a bit more convenient for some callers, but more importantly, it is
easier to implement correctly. Doing this removes the patching of already
printed data that was used for fastcall, fixing a crash with private fastcall
symbols.
llvm-svn: 200367
When the scalar compare is between floating point and operands are
vector, we custom lower SELECT_CC to use NEON SIMD compare for
generating less instructions.
llvm-svn: 200365
Make sure that we don't introduce illegal build_vector dag nodes
when trying to fold a sign_extend of a build_vector.
This fixes a regression introduced by r200234.
Added test CodeGen/X86/fold-vector-sext-crash.ll
to verify that llc no longer crashes with an assertion failure
due to an illegal build_vector of type MVT::v4i64.
Thanks to Ilia Filippov for spotting this regression and for
providing a reproducible test case.
llvm-svn: 200313
GPRC_NOR0 is not a subclass of GPRC (because it also contains the ZERO pseudo
register). As a result, we also need to check for it in the spilling code.
llvm-svn: 200288
Summary:
This commit gives an address mode to the PLD instruction. We
were getting an assertion failure in the frame lowering code
because we had code that was doing a pld of a stack allocated
address. The frame lowering was checking the address mode and
then asserting because pld had none defined.
This commit fixes pld for arm mode. There was a previous fix for
thumb mode in a separate commit. The commit for thumb mode
added a test in a separate file because it would otherwise fail
for arm. This commit moves the thumb test back into the prefetch.ll
file and adds the corresponding arm test.
Differential Revision: http://llvm-reviews.chandlerc.com/D2622
llvm-svn: 200248
This patch teaches the DAGCombiner how to fold a sext/aext/zext dag node when
the operand in input is a build vector of constants (or UNDEFs).
The inability to fold a sext/zext of a constant build_vector was the root
cause of some pcg bugs affecting vselect expansion on x86-64 with AVX support.
Before this change, the DAGCombiner only knew how to fold a sext/zext/aext of a
ConstantSDNode.
llvm-svn: 200234
Issue outcomes from DAGCombiner::MergeConsequtiveStores, more precisely from
mem-ops sequence sorting.
Consider, how MergeConsequtiveStores works for next example:
store i8 1, a[0]
store i8 2, a[1]
store i8 3, a[1] ; a[1] again.
return ; DAG starts here
1. Method will collect all the 3 stores.
2. It sorts them by distance from the base pointer (farthest with highest
index).
3. It takes first consecutive non-overlapping stores and (if possible) replaces
them with a single store instruction.
The point is, we can't determine here which 'store' instruction
would be the second after sorting ('store 2' or 'store 3').
It happens that 'store 3' would be the second, and 'store 2' would be the third.
So after merging we have the next result:
store i16 (1 | 3 << 8), base ; is a[0] but bit-casted to i16
store i8 2, a[1]
So actually we swapped 'store 3' and 'store 2' and got wrong contents in a[1].
Fix: In sort routine just also take into account mem-op sequence number.
llvm-svn: 200201
These were:
* noreorder handling on the target object streamer and asm parser.
* setting the initial flag bits based on the enabled features.
* setting the elf header flag for micromips
It is *really* depressing I am the one doing this instead of someone at
mips actually taking the time to understand the infrastructure.
llvm-svn: 200138
I disabled the use of TBAA in CodeGen in r200093. This adds a test case that
demonstrates the problems with inttoptr and TBAA in CodeGen (and, specifically,
the problem that causes LLVM to miscompile itself in Release mode). This test
will currently fail if -use-tbaa-in-sched-mi is enabled.
llvm-svn: 200097
r200064 depends on r200051.
r200051 is broken: I tries to replace .mips_hack_elf_flags, which is a good
thing, but what it replaces it with is even worse.
The new emitMipsELFFlags it adds corresponds to no assembly directive, is not
marked as a hack and is not even printed to the .s file.
The patch also introduces more uses of hasRawTextSupport.
The correct way to remove .mips_hack_elf_flags is to have the mips target
streamer handle the default flags (and command line options). That way the
same code path is used for asm and obj. The streamer interface should *really*
correspond to what is printed in the .s file.
llvm-svn: 200078
This commit caused -Woverloaded-virtual warnings. The two new
TargetTransformInfo::getIntImmCost functions were only added to the superclass,
and to the X86 subclass. The other targets were not updated, and the
warning highlighted this by pointing out that e.g. ARMTTI::getIntImmCost was
hiding the two new getIntImmCost variants.
We could pacify the warning by adding "using TargetTransformInfo::getIntImmCost"
to the various subclasses, or turning it off, but I suspect that it's wrong to
leave the functions unimplemnted in those targets. The default implementations
return TCC_Free, which I don't think is right e.g. for ARM.
llvm-svn: 200058
The i8 type is not registered with any register class.
This causes a segmentation fault in MachineLICM::getRegisterClassIDAndCost.
The code selects the first type associated with register class FPR8,
which happens to be i8.
It uses this type (i8) to get the representative class pointer, which is 0.
It then uses this pointer to access a field, resulting in segmentation fault.
Since i8 type is not being used for printing any neon instruction
we can safely remove it.
llvm-svn: 200046
Retry commit r200022 with a fix for the build bot errors. Constant expressions
have (unlike instructions) module scope use lists and therefore may have users
in different functions. The fix is to simply ignore these out-of-function uses.
llvm-svn: 200034
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.
First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.
If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.
When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.
This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)
Reviewed by Eric
llvm-svn: 200022
This commit teaches the X86 backend to create the same X86 instructions when it
lowers an sadd/ssub with overflow intrinsic and a conditional branch that uses
that overflow result. This allows SelectionDAG to recognize and remove one of
the redundant operations.
This fixes <rdar://problem/15874016> and <rdar://problem/15661073>.
Reviewed by Nadav
llvm-svn: 199976
Originally, BLX was passed as operand #0 in MachineInstr and as operand
#2 in MCInst. But now, it's operand #2 in both cases.
This patch also removes unnecessary FileCheck in the test case added by r199127.
llvm-svn: 199928
This pattern uses an SDNodeXForm, which isn't being emitted for some
reason. I can get it to work by attaching the PatLeaf that has the
XForm to the argument in the output pattern, but this results in an
immediate being used in a register operand, which the backend can't
handle yet.
llvm-svn: 199918
The control flow finalizer would sometimes use an ALU_POP_AFTER
instruction before the vetex fetch clause instead of using a POP
instruction after it.
llvm-svn: 199917
Implement the getUnrollingPreferences() function for
AMDGPUTargetTransformInfo so that loops that do address calculations
on pointers derived from alloca are unconditionally unrolled.
Unrolling these loops makes it more likely that SROA will be able to
eliminate the allocas, which is a big win for R600 since memory
allocated by alloca (private memory) is really slow.
llvm-svn: 199916
The unit test is now disabled on non-asserts builds.
The CF stack can be corrupted if you use CF_ALU_PUSH_BEFORE,
CF_ALU_ELSE_AFTER, CF_ALU_BREAK, or CF_ALU_CONTINUE when the number of
sub-entries on the stack is greater than or equal to the stack entry
size and sub-entries modulo 4 is either 0 or 3 (on cedar the bug is
present when number of sub-entries module 8 is either 7 or 0)
We choose to be conservative and always apply the work-around when the
number of sub-enries is greater than or equal to the stack entry size,
so that we can safely over-allocate the stack when we are unsure of the
stack allocation rules.
reviewed-by: Vincent Lejeune <vljn at ovi.com>
llvm-svn: 199905
With constant-sharing, litpool loads consume 4 + N*2 bytes of code, but
movw/movt pairs consume 8*N. This means litpools are better than movw/movt even
with just one use. Other materialisation strategies can still be better though,
so the logic is a little odd.
llvm-svn: 199891
This is a horrible bit of code. We're calling a simplification routine *in the middle* of type legalization. We tell the
simplification routine that it's running after legalization, but some of the types it will encounter will be illegal! The
fix is only to invoke the simplification if the types in question were legal, so that none of its invariants will be violated.
llvm-svn: 199847
This reverts commit 35b8331cad6eb512a2506adbc394201181da94ba.
The -debug-only flag for llc doesn't appear to be available in
all build configurations.
llvm-svn: 199845
The CF stack can be corrupted if you use CF_ALU_PUSH_BEFORE,
CF_ALU_ELSE_AFTER, CF_ALU_BREAK, or CF_ALU_CONTINUE when the number of
sub-entries on the stack is greater than or equal to the stack entry
size and sub-entries modulo 4 is either 0 or 3 (on cedar the bug is
present when number of sub-entries module 8 is either 7 or 0)
We choose to be conservative and always apply the work-around when the
number of sub-enries is greater than or equal to the stack entry size,
so that we can safely over-allocate the stack when we are unsure of the
stack allocation rules.
reviewed-by: Vincent Lejeune <vljn at ovi.com>
llvm-svn: 199842
This patch restores the ARM mode if the user's inline assembly
does not. In the object streamer, it ensures that instructions
following the inline assembly are encoded correctly and that
correct mapping symbols are emitted. For the asm streamer, it
emits a .arm or .thumb directive.
This patch does not ensure that the inline assembly contains
the ADR instruction to switch modes at runtime.
The problem we need to solve is code like this:
int foo(int a, int b) {
int r = a + b;
asm volatile(
".align 2 \n"
".arm \n"
"add r0,r0,r0 \n"
: : "r"(r));
return r+1;
}
If we compile this function in thumb mode then the inline assembly
will switch to arm mode. We need to make sure that we switch back to
thumb mode after emitting the inline assembly or we will incorrectly
encode the instructions that follow (i.e. the assembly instructions
for return r+1).
Based on patch by David Peixotto
Change-Id: Ib57f6d2d78a22afad5de8693fba6230ff56ba48b
llvm-svn: 199818
This actually totally breaks and causes the machine verifier to cry in several cases, one of which being:
%RAX<def> = COPY %RCX<kill>
%ECX<def> = COPY %EAX<kill>, %RAX<imp-use,kill>
These subregister copies are together identified as noops, so are both removed. However, the second one as it has an imp-use gets converted into a kill:
%ECX<def> = KILL %EAX<kill>, %RAX<imp-use,kill>
As the original COPY has been removed, the verifier goes into tears at the use of undefined EAX and RAX.
There are several hacky solutions to this hacky problem (which is all to do with imp-use/def weirdnesses), but the least hacky I've come up with is to *always* remove COPYs by converting to KILLs. KILLs are no-ops to the code generator so the generated code doesn't change (which is why they were partially used in the first place), but using them also keeps the def/use and imp-def/imp-use chains alive:
%RAX<def> = KILL %RCX<kill>
%ECX<def> = KILL %EAX<kill>, %RAX<imp-use,kill>
The patch passes all test cases including the ones that check the removal of MOVs in this circumstance, along with an extra test I added to check subregister behaviour (which made the machine verifier fall over before my patch).
The patch also adds some DEBUG() statements because the file hadn't got any.
llvm-svn: 199797
Reid Kleckner