If a live range is used by a terminator instruction, and that live range needs
to leave the block on the stack or in a different register, it can be necessary
to have both sides of the split live at the terminator instruction.
Example:
%vreg2 = COPY %vreg1
JMP %vreg1
Becomes after spilling %vreg2:
SPILL %vreg1
JMP %vreg1
The spill doesn't kill the register as is normally the case.
llvm-svn: 125102
Avoid using the same register for two def operands or and earlyclobber
def and use operand. This fixes PR8986 and improves on the prior fix
for rdar://problem/8959122.
llvm-svn: 125089
t2LDRpci with t2LDRi12.
There are a couple of problems with this.
1. The encoding for the literal and immediate constant are different.
Note bit 7 of the literal case is 'U' so it can be negative.
2. t2LDRi12 is now narrowed to tLDRpci before constant island pass is run.
So we end up never using the Thumb2 instruction, which ends up creating a
lot more constant islands.
llvm-svn: 125074
the active loop. This is generally desirable, and it avoids trouble
in situations such as the testcase in PR9123, though the failure
mode depends on use-list order, so it is infeasible to test.
llvm-svn: 125065
After uses of a live range are removed, recompute the live range to only cover
the remaining uses. This is necessary after rematerializing the value before
some (but not all) uses.
llvm-svn: 125058
parsing of operands introduced in r125030. As a small note, besides using a more
generic approach we can also have more descriptive output when debugging
llvm-mc, example:
mcr p7, #1, r5, c1, c1, #4
note: parsed instruction:
['mcr', <ARMCC::al>,
<coprocessor number: 7>,
1,
<register 73>,
<coprocessor register: 1>,
<coprocessor register: 1>,
4]
llvm-svn: 125052
The vld1-lane, vld1-dup and vst1-lane instructions do not yet support using
post-increment versions, but all the rest of the NEON load/store instructions
should be handled now.
llvm-svn: 125014
These operations are expanded to pairs of loads or stores, and the first one
uses the address register update to produce the address for the second one.
So far, the second load/store has also updated the address register, just
for convenience, since that output has never been used. In anticipation of
actually supporting post-increment updates for these operations, this changes
the non-updating operations to use a non-updating load/store for the second
instruction.
llvm-svn: 125013
failures with relocations.
The code committed is a first cut at compatibility for emitted relocations in
ELF .o.
Why do this? because existing ARM tools like emitting relocs symbols as
explicit relocations, not as section-offset relocs.
Result is that with these changes,
1) relocs are now substantially identical what to gcc outputs.
2) larger apps (including many spec2k tests) compile, cross-link, and pass
Added reminder fixme to tests for future conversion to .s form.
llvm-svn: 124996
<rdar://problem/8959122> illegal register operands for UMULL instruction in cfrac nightly test
I'm stil working on a unit test, but the case is:
rx = movcc rx, r3
r2 = ldr
r2, r3 = umull r2, r2
The anti-dep breaker should not convert this into an illegal instruction:
r2, r2 = umull
llvm-svn: 124932
a) Making it a per call site bonus for functions that we can move from
indirect to direct calls.
b) Reduces the bonus from 500 to 100 per call site.
c) Subtracts the size of the possible newly inlineable call from the
bonus to only add a bonus if we can inline a small function to devirtualize
it.
Also changes the bonus from a positive that's subtracted to a negative
that's added.
Fixes the remainder of rdar://8546196 by reducing the object file size
after inlining by 84%.
llvm-svn: 124916
This allows us to easily support 256-bit operations that don't have
native 256-bit support. This applies to integer operations, certain
types of shuffles and various othher things.
llvm-svn: 124910
If interference reaches the last split point, it is effectively live out and
should be marked as 'MustSpill'.
This can make a difference when the terminator uses a register. There is no way
that register can be reused in the outgoing CFG bundle, even if it isn't live
out.
llvm-svn: 124900
(yes, this is different from R_ARM_CALL)
- Adds a new method getARMBranchTargetOpValue() which handles the
necessary distinction between the conditional and unconditional br/bl
needed for ARM/ELF
At least for ARM mode, the needed fixup for conditional versus unconditional
br/bl is identical, but the ARM docs and existing ARM tools expect this
reloc type...
Added a few FIXME's for future naming fixups in ARMInstrInfo.td
llvm-svn: 124895
A live range cannot be split everywhere in a basic block. A split must go before
the first terminator, and if the variable is live into a landing pad, the split
must happen before the call that can throw.
llvm-svn: 124894
We should not be attempting a region split if it won't lead to at least one
directly allocatable interval. That could cause infinite splitting loops.
llvm-svn: 124893
precisely track pressure on a selection DAG, but we can at least keep
it balanced. This design accounts for various interesting aspects of
selection DAGS: register and subregister copies, glued nodes, dead
nodes, unused registers, etc.
Added SUnit::NumRegDefsLeft and ScheduleDAGSDNodes::RegDefIter.
Note: I disabled PrescheduleNodesWithMultipleUses when register
pressure is enabled, based on no evidence other than I don't think it
makes sense to have both enabled.
llvm-svn: 124853
When the live range is live through a block that doesn't use the register, but
that has interference, region splitting wants to split at the top and bottom of
the basic block.
llvm-svn: 124839
Allow a live range to end with a kill flag, but don't allow a kill flag that
doesn't end the live range.
This makes the machine code verifier more useful during register allocation when
kill flag computation is deferred.
llvm-svn: 124838
If the found value is not live-through the block, we should only add liveness up
to the requested slot index. When the value is live-through, the whole block
should be colored.
Bug found by SSA verification in the machine code verifier.
llvm-svn: 124812
matching EXTRACT_SUBVECTOR to VEXTRACTF128 along with support routines
to examine and translate index values. VINSERTF128 comes next. With
these two in place we can begin supporting more AVX operations as
INSERT/EXTRACT can be used as a fallback when 256-bit support is not
available.
llvm-svn: 124797
auto-simplifier). This has a big impact on Ada code, but not much else.
Unfortunately the impact is mostly negative! This is due to PR9004 (aka
SCCP failing to resolve conditional branch conditions in the destination
blocks of the branch), in which simple correlated expressions are not
resolved but complicated ones are, so simplifying has a bad effect!
llvm-svn: 124788
Reversing the operands allows us to fold, but doesn't force us to. Also, at
this point the DAG is still being optimized, so the check for hasOneUse is not
very precise.
llvm-svn: 124773
The greedy register allocator revealed some problems with the value mapping in
SplitKit. We would sometimes start mapping values before all defs were known,
and that could change a value from a simple 1-1 mapping to a multi-def mapping
that requires ssa update.
The new approach collects all defs and register assignments first without
filling in any live intervals. Only when finish() is called, do we compute
liveness and mapped values. At this time we know with certainty which values map
to multiple values in a split range.
This also has the advantage that we can compute live ranges based on the
remaining uses after rematerializing at split points.
The current implementation has many opportunities for compile time optimization.
llvm-svn: 124765
overflow (nsw flag), which was disabled because it breaks 254.gap. I have
informed the GAP authors of the mistake in their code, and arranged for the
testsuite to use -fwrapv when compiling this benchmark.
llvm-svn: 124746
This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.
We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.
The testcase from README.txt now compiles into
decl %edi
cmpl $3, %edi
sbbl %eax, %eax
andl $1, %eax
ret
llvm-svn: 124724
may be useful to understand "none", this is not the place for it. Tweak
the fix to Normalize while there: the fix added in 123990 works correctly,
but I like this way better. Finally, now that Triple understands some
non-trivial environment values, teach the unittests about them.
llvm-svn: 124720
that might have changed been affected by a merge elsewhere will have been
removed from the function set, and it isn't needed for performance because we
call grow() ahead of time to prevent reallocations.
llvm-svn: 124717
the load, then it may be legal to transform the load and store to integer
load and store of the same width.
This is done if the target specified the transformation as profitable. e.g.
On arm, this can transform:
vldr.32 s0, []
vstr.32 s0, []
to
ldr r12, []
str r12, []
rdar://8944252
llvm-svn: 124708
This is similar to the -unroll-threshold option. There should be no change in
behavior when -tail-dup-size is not explicit on the llc command line.
llvm-svn: 124564
to do this and more, but would only do it if X/Y had only one use. Spotted as the
most common missed simplification in SPEC by my auto-simplifier, now that it knows
about nuw/nsw/exact flags. This removes a bunch of multiplications from 447.dealII
and 483.xalancbmk. It also removes a lot from tramp3d-v4, which results in much
more inlining.
llvm-svn: 124560
This happens all the time when a smul is promoted to a larger type.
On x86-64 we now compile "int test(int x) { return x/10; }" into
movslq %edi, %rax
imulq $1717986919, %rax, %rax
movq %rax, %rcx
shrq $63, %rcx
sarq $34, %rax <- used to be "shrq $32, %rax; sarl $2, %eax"
addl %ecx, %eax
This fires 96 times in gcc.c on x86-64.
llvm-svn: 124559
This happens e.g. for code like "X - X%10" where we lower the modulo operation
to a series of multiplies and shifts that are then subtracted from X, leading to
this missed optimization.
llvm-svn: 124532
Modified patch by Adam Preuss.
This builds on the existing framework for block tracing, edge profiling and optimal edge profiling.
See -help-hidden for new flags.
For documentation, see the technical report "Implementation of Path Profiling..." in llvm.org/pubs.
llvm-svn: 124515
benchmarks, and that it can be simplified to X/Y. (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case). This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too. This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too. It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.
llvm-svn: 124487
