support for the case where alignment<value size.
These cases were silently miscompiled before this patch.
Now they are overly verbose -especially storing is- and
any front-end should still avoid misaligned memory
accesses as much as possible. The bit juggling algorithm
added here probably has some room for improvement still.
llvm-svn: 118889
It is only supported for ARM code. Normally Thumb2 code would use DMB instead,
but depending on how the compiler is invoked (e.g., -mattr=-db) that might be
disabled. This prevents a "cannot select MEMBARRIER_MCR" error in that
situation. Radar 8644195
llvm-svn: 118642
exposed:
GAS doesn't accept "fcomip %st(1)", it requires "fcomip %st(1), %st(0)"
even though st(0) is implicit in all other fp stack instructions.
Fortunately, there is an alias for fcomip named "fcompi" and gas does
accept the default argument for the alias (boggle!).
As such, switch the canonical form of this instruction to "pi" instead
of "ip". This makes the code generator and disassembler generate pi,
avoiding the gas bug.
llvm-svn: 118356
sequence of loads and stores was being generated to perform the
copy on the x86 targets if the parameter was less than 4 byte
aligned, causing llc to use up vast amounts of memory and time.
Use a "rep movs" form instead. PR7170.
llvm-svn: 118260
1. Fix pre-ra scheduler so it doesn't try to push instructions above calls to
"optimize for latency". Call instructions don't have the right latency and
this is more likely to use introduce spills.
2. Fix if-converter cost function. For ARM, it should use instruction latencies,
not # of micro-ops since multi-latency instructions is completely executed
even when the predicate is false. Also, some instruction will be "slower"
when they are predicated due to the register def becoming implicit input.
rdar://8598427
llvm-svn: 118135
at more than those which define CPSR. You can have this situation:
(1) subs ...
(2) sub r6, r5, r4
(3) movge ...
(4) cmp r6, 0
(5) movge ...
We cannot convert (2) to "subs" because (3) is using the CPSR set by
(1). There's an analogous situation here:
(1) sub r1, r2, r3
(2) sub r4, r5, r6
(3) cmp r4, ...
(5) movge ...
(6) cmp r1, ...
(7) movge ...
We cannot convert (1) to "subs" because of the intervening use of CPSR.
llvm-svn: 117950
There were a number of issues to fix up here:
* The "device" argument of the llvm.memory.barrier intrinsic should be
used to distinguish the "Full System" domain from the "Inner Shareable"
domain. It has nothing to do with using DMB vs. DSB instructions.
* The compiler should never need to emit DSB instructions. Remove the
ARMISD::SYNCBARRIER node and also remove the instruction patterns for DSB.
* Merge the separate DMB/DSB instructions for options only used for the
disassembler with the default DMB/DSB instructions. Add the default
"full system" option ARM_MB::SY to the ARM_MB::MemBOpt enum.
* Add a separate ARMISD::MEMBARRIER_MCR node for subtargets that implement
a data memory barrier using the MCR instruction.
* Fix up encodings for these instructions (except MCR).
I also updated the tests and added a few new ones to check for DMB options
that were not currently being exercised.
llvm-svn: 117756
operand and one of them has a single use that is a live out copy, favor the
one that is live out. Otherwise it will be difficult to eliminate the copy
if the instruction is a loop induction variable update. e.g.
BB:
sub r1, r3, #1
str r0, [r2, r3]
mov r3, r1
cmp
bne BB
=>
BB:
str r0, [r2, r3]
sub r3, r3, #1
cmp
bne BB
This fixed the recent 256.bzip2 regression.
llvm-svn: 117675
- For now, loads of [r, r] addressing mode is the same as the
[r, r lsl/lsr/asr #] variants. ARMBaseInstrInfo::getOperandLatency() should
identify the former case and reduce the output latency by 1.
- Also identify [r, r << 2] case. This special form of shifter addressing mode
is "free".
llvm-svn: 117519
elements than the result vector type. So, when an instruction like:
%8 = shufflevector <2 x float> %4, <2 x float> %7, <4 x i32> <i32 1, i32 0, i32 3, i32 2>
is translated to a DAG, each operand is changed to a concat_vectors node that appends 2 undef elements. That is:
shuffle [a,b], [c,d] is changed to:
shuffle [a,b,u,u], [c,d,u,u]
That's probably the right thing for x86 but for NEON, we'd much rather have:
shuffle [a,b,c,d], undef
Teach the DAG combiner how to do that transformation for ARM. Radar 8597007.
llvm-svn: 117482
The SPU ABI does not mention v64, and all examples
in C suggest v128 are treated similarily to arrays,
we use array alignment for v64 too. This makes the
alignment of e.g. [2 x <2 x i32>] behave "intuitively"
and similar to as if the elements were e.g. i32s.
This also makes an "unaligned store" test to be
aligned, with different (but functionally equivalent)
code generated.
llvm-svn: 117360
do not double-count the duplicate instructions by counting once from the
beginning and again from the end. Keep track of where the duplicates from
the beginning ended and don't go past that point when counting duplicates
at the end. Radar 8589805.
This change causes one of the MC/ARM/simple-fp-encoding tests to produce
different (better!) code without the vmovne instruction being tested.
I changed the test to produce vmovne and vmoveq instructions but moving
between register files in the opposite direction. That's not quite the same
but predicated versions of those instructions weren't being tested before,
so at least the test coverage is not any worse, just different.
llvm-svn: 117333
1. A delay slot filler that searches for valid instructions
to fill the delay slot with. Previously NOPs would always
be inserted into delay slots.
2. Support for MC based instruction printer added.
3. Support for MC based machine code generation and ELF
file generation. ELF file generation does not yet
completely work as much of the ELF support infrastructure
is still x86/x86-64 specific.
4. General clean up of the MBlaze backend code. Much of the
tablegen code has been cleanup and simplified.
Bug Fixes:
1. Removed duplicate periods from subtarget feature descriptions.
2. Many of the instructions had bad machine code information
in the tablegen files. Much of this has been fixed.
llvm-svn: 116986
- Initial register pressure in the loop should be all the live defs into the
loop. Not just those from loop preheader which is often empty.
- When an instruction is hoisted, update register pressure from loop preheader
to the original BB.
- Treat only use of a virtual register as kill since the code is still SSA.
llvm-svn: 116956
"long latency" enough to hoist even if it may increase spilling. Reloading
a value from spill slot is often cheaper than performing an expensive
computation in the loop. For X86, that means machine LICM will hoist
SQRT, DIV, etc. ARM will be somewhat aggressive with VFP and NEON
instructions.
- Enable register pressure aware machine LICM by default.
llvm-svn: 116781
The old algorithm inserted a 'rotqmbyi' instruction which was
both redundant and wrong - it made shufb select bytes from the
wrong end of the input quad.
llvm-svn: 116701
have been printed with the "S" modifier after the predicate. With ARM's
unified syntax, they are supposed to go in the other order. We fixed this
for Thumb when we switched to unified syntax but missed changing it for
ARM. Apparently we don't generate these instructions often because no one
noticed until now. Thanks to Bill Wendling for the testcase!
llvm-svn: 116563
alignment for PPC32/64, avoiding some masking operations.
llvm-gcc expands vaarg inline instead of using the instruction
so it has never hit this.
llvm-svn: 116168
1. Cortex-A8 load / store multiplies can only issue on ALU0.
2. Eliminate A8_Issue, A8_LSPipe will correctly limit the load / store issues.
3. Correctly model all vld1 and vld2 variants.
llvm-svn: 116134
callee-saved registers at the end of the lists. Also prefer to avoid using
the low registers that are in register subclasses required by certain
instructions, so that those registers will more likely be available when needed.
This change makes a huge improvement in spilling in some cases. Thanks to
Jakob for helping me realize the problem.
Most of this patch is fixing the testsuite. There are quite a few places
where we're checking for specific registers. I changed those to wildcards
in places where that doesn't weaken the tests. The spill-q.ll and
thumb2-spill-q.ll tests stopped spilling with this change, so I added a bunch
of live values to force spills on those tests.
llvm-svn: 116055
reapply: reimplement the second half of the or/add optimization. We should now
with no changes. Turns out that one missing "Defs = [EFLAGS]" can upset things
a bit.
llvm-svn: 116040
only end up emitting LEA instead of OR. If we aren't able to promote
something into an LEA, we should never be emitting it as an ADD.
Add some testcases that we emit "or" in cases where we used to produce
an "add".
llvm-svn: 116026
allow target to correctly compute latency for cases where static scheduling
itineraries isn't sufficient. e.g. variable_ops instructions such as
ARM::ldm.
This also allows target without scheduling itineraries to compute operand
latencies. e.g. X86 can return (approximated) latencies for high latency
instructions such as division.
- Compute operand latencies for those defined by load multiple instructions,
e.g. ldm and those used by store multiple instructions, e.g. stm.
llvm-svn: 115755
having to do a double cast (uint64_t --> double --> float). This is based on the algorithm from compiler_rt's __floatundisf
for X86-64.
llvm-svn: 115634
The x86_mmx type is used for MMX intrinsics, parameters and
return values where these use MMX registers, and is also
supported in load, store, and bitcast.
Only the above operations generate MMX instructions, and optimizations
do not operate on or produce MMX intrinsics.
MMX-sized vectors <2 x i32> etc. are lowered to XMM or split into
smaller pieces. Optimizations may occur on these forms and the
result casted back to x86_mmx, provided the result feeds into a
previous existing x86_mmx operation.
The point of all this is prevent optimizations from introducing
MMX operations, which is unsafe due to the EMMS problem.
llvm-svn: 115243
edited during emission.
If the basic block ends in a switch that gets lowered to a jump table, any
phis at the default edge were getting updated wrong. The jump table data
structure keeps a pointer to the header blocks that wasn't getting updated
after the MBB is split.
This bug was exposed on 32-bit Linux when disabling critical edge splitting in
codegen prepare.
The fix is to uipdate stale MBB pointers whenever a block is split during
emission.
llvm-svn: 115191
cost modeling for if-conversion. Now if only we had a way to estimate the misprediction probability.
Adjsut CodeGen/ARM/ifcvt10.ll. The pipeline on Cortex-A8 is long enough that it is still profitable
to predicate an ldm, but the shorter pipeline on Cortex-A9 makes it unprofitable.
llvm-svn: 114995
Rather than having arbitrary cutoffs, actually try to cost model the conversion.
For now, the constants are tuned to more or less match our existing behavior, but these will be
changed to reflect realistic values as this work proceeds.
llvm-svn: 114973
This reverts revision 114633. It was breaking llvm-gcc-i386-linux-selfhost.
It seems there is a downstream bug that is exposed by
-cgp-critical-edge-splitting=0. When that bug is fixed, this patch can go back
in.
Note that the changes to tailcallfp2.ll are not reverted. They were good are
required.
llvm-svn: 114859
x86-32: 32-bit calls were named "call" not "calll". 64-bit calls were correctly
named "callq", so this only impacted x86-32.
This fixes rdar://8456370 - llvm-mc rejects 'calll'
This also exposes that mingw/64 is generating a 32-bit call instead of a 64-bit call,
I will file a bugzilla.
llvm-svn: 114534
(sbbl x, x) sets the registers to 0 or ~0. Combined with two's complement arithmetic, we can fold
the intermediate AND and the ADD into a single SUB.
This fixes <rdar://problem/8449754>.
llvm-svn: 114460
CombinerAA cannot assume that different FrameIndex's never alias, but can instead use
MachineFrameInfo to get the actual offsets of these slots and check for actual aliasing.
This fixes CodeGen/X86/2010-02-19-TailCallRetAddrBug.ll and CodeGen/X86/tailcallstack64.ll
when CombinerAA is enabled, modulo a different register allocation sequence.
llvm-svn: 114348
between the high and low registers for prologue/epilogue code. This was
a Darwin-only thing that wasn't providing a realistic benefit anymore.
Combining the save areas simplifies the compiler code and results in better
ARM/Thumb2 codegen.
For example, previously we would generate code like:
push {r4, r5, r6, r7, lr}
add r7, sp, #12
stmdb sp!, {r8, r10, r11}
With this change, we combine the register saves and generate:
push {r4, r5, r6, r7, r8, r10, r11, lr}
add r7, sp, #12
rdar://8445635
llvm-svn: 114340
NO path to the destination containing side effects, not that SOME path contains no side effects.
In practice, this only manifests with CombinerAA enabled, because otherwise the chain has little
to no branching, so "any" is effectively equivalent to "all".
llvm-svn: 114268
value should be in GPRs when it's going to be used as a scalar, and we use
VMOVRRD to make that happen, but if the value is converted back to a vector
we need to fold to a simple bit_convert. Radar 8407927.
llvm-svn: 114233
1) Do forward copy propagation. This makes it easier to estimate the cost of the
instruction being sunk.
2) Break critical edges on demand, including cases where the value is used by
PHI nodes.
Critical edge splitting is not yet enabled by default.
llvm-svn: 114227
legacy asm printer uses instructions of the form, "mov r0, r0, lsl #3", while
the MC-instruction printer uses the form "lsl r0, r0, #3". The latter mnemonic
is correct and preferred according the ARM documentation (A8.6.98). The former
are pseudo-instructions for the latter.
llvm-svn: 114221
walking the asm arguments once and stashing their Values. This is
wrong because the same memory location can be in the list twice, and
if the first one has a sunkaddr substituted, the stashed value for the
second one will be wrong (use-after-free). PR 8154.
llvm-svn: 114104
This cleans up after the mess r108567 left in the CellSPU backend.
ORCvt-instruction were used to reinterpret registers, and the ORs were then
removed by isMoveInstr(). This patch now removes 350 instrucions of format:
or $3, $3, $3
(from the 52 testcases in CodeGen/CellSPU). One case of a nonexistant or is
checked for.
Some moves of the form 'ori $., $., 0' and 'ai $., $., 0' still remain.
llvm-svn: 114074
encountered while building llvm-gcc for arm. This is probably the same issue
that the ppc buildbot hit. llvm::prior works on a MachineBasicBlock::iterator,
not a plain MachineInstr.
llvm-svn: 113983
backing out following to get it back to green,
so I can investigate in peace:
svn merge -c -113840 llvm/test/CodeGen/ARM/arm-and-tst-peephole.ll
svn merge -c -113876 -c -113839 llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
llvm-svn: 113980
to expose greater opportunities for store narrowing in codegen. This patch fixes a potential
infinite loop in instcombine caused by one of the introduced transforms being overly aggressive.
llvm-svn: 113763
to use AddrMode4, there was a count of the registers stored in one of the
operands. I changed that to just count the operands but forgot to adjust for
the size of D registers. This was noticed by Evan as a performance problem
but it is a potential correctness bug as well, since it is possible that this
could merge a base update with a non-matching immediate.
llvm-svn: 113576
take multiple cycles to decode.
For the current if-converter clients (actually only ARM), the instructions that
are predicated on false are not nops. They would still take machine cycles to
decode. Micro-coded instructions such as LDM / STM can potentially take multiple
cycles to decode. If-converter should take treat them as non-micro-coded
simple instructions.
llvm-svn: 113570
Since mem2reg isn't run at -O0, we get a ton of reloads from the stack,
for example, before, this code:
int foo(int x, int y, int z) {
return x+y+z;
}
used to compile into:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
movl 4(%rsp), %esi
addl %edx, %esi
movl (%rsp), %edx
addl %esi, %edx
movl %edx, %eax
addq $12, %rsp
ret
Now we produce:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
addl 4(%rsp), %edx ## Folded load
addl (%rsp), %edx ## Folded load
movl %edx, %eax
addq $12, %rsp
ret
Fewer instructions and less register use = faster compiles.
llvm-svn: 113102
"For ARM stack frames that utilize variable sized objects and have either
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs."
r112986 fixed a latent bug exposed by the above.
llvm-svn: 112989
vabd intrinsic and add and/or zext operations. In the case of vaba, this
also avoids the need for a DAG combine pattern to combine vabd with add.
Update tests. Auto-upgrade the old intrinsics.
llvm-svn: 112941
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs.
rdar://7352504
rdar://8374540
rdar://8355680
llvm-svn: 112883
there are clearly no stores between the load and the store. This fixes
this miscompile reported as PR7833.
This breaks the test/CodeGen/X86/narrow_op-2.ll optimization, which is
safe, but awkward to prove safe. Move it to X86's README.txt.
llvm-svn: 112861
add, and subtract operations with zero-extended or sign-extended vectors.
Update tests. Add auto-upgrade support for the old intrinsics.
llvm-svn: 112773
check more strict, breaking some cases not checked in the
testsuite, but also exposes some foldings not done before,
as this example:
movaps (%rdi), %xmm0
movaps (%rax), %xmm1
movaps %xmm0, %xmm2
movss %xmm1, %xmm2
shufps $36, %xmm2, %xmm0
now is generated as:
movaps (%rdi), %xmm0
movaps %xmm0, %xmm1
movlps (%rax), %xmm1
shufps $36, %xmm1, %xmm0
llvm-svn: 112753
int x(int t) {
if (t & 256)
return -26;
return 0;
}
We generate this:
tst.w r0, #256
mvn r0, #25
it eq
moveq r0, #0
while gcc generates this:
ands r0, r0, #256
it ne
mvnne r0, #25
bx lr
Scandalous really!
During ISel time, we can look for this particular pattern. One where we have a
"MOVCC" that uses the flag off of a CMPZ that itself is comparing an AND
instruction to 0. Something like this (greatly simplified):
%r0 = ISD::AND ...
ARMISD::CMPZ %r0, 0 @ sets [CPSR]
%r0 = ARMISD::MOVCC 0, -26 @ reads [CPSR]
All we have to do is convert the "ISD::AND" into an "ARM::ANDS" that sets [CPSR]
when it's zero. The zero value will all ready be in the %r0 register and we only
need to change it if the AND wasn't zero. Easy!
llvm-svn: 112664
1) nuke ConstDataCoalSection, which is dead.
2) revise my previous patch for rdar://8018335,
which was completely wrong. Specifically, it doesn't
make sense to mark __TEXT,__const_coal as PURE_INSTRUCTIONS,
because it is for readonly data. templates (it turns out)
go to const_coal_nt. The real fix for rdar://8018335 was
to give ConstTextCoalSection a section kind of ReadOnly
instead of Text.
llvm-svn: 112496
Chris Lattner