if the extension types were not the same. The result was that if you
fed a select with sext and zext loads, as in the testcase, then it
would get turned into a zext (or sext) of the select, which is wrong
in the cases when it should have been an sext (resp. zext). Reported
and diagnosed by Sebastien Deldon.
llvm-svn: 119728
preserves LCSSA form out of ScalarEvolution and into the LoopInfo
class. Use it to check that SimplifyInstruction simplifications
are not breaking LCSSA form. Fixes PR8622.
llvm-svn: 119727
Remove movePastCSLoadStoreOps and associated code for simple pointer
increments. Update routines that depended upon other opcodes for save/restore.
Adjust all testcases accordingly.
llvm-svn: 119725
this was a tree of hashtables, and a query recursed into the table for the immediate dominator ad infinitum
if the initial lookup failed. This led to really bad performance on tall, narrow CFGs.
We can instead replace it with what is conceptually a multimap of value numbers to leaders (actually
represented by a hashtable with a list of Value*'s as the value type), and then
determine which leader from that set to use very cheaply thanks to the DFS numberings maintained by
DominatorTree. Because there are typically few duplicates of a given value, this scan tends to be
quite fast. Additionally, we use a custom linked list and BumpPtr allocation to avoid any unnecessary
allocation in representing the value-side of the multimap.
This change brings with it a 15% (!) improvement in the total running time of GVN on 403.gcc, which I
think is pretty good considering that includes all the "real work" being done by MemDep as well.
The one downside to this approach is that we can no longer use GVN to perform simple conditional progation,
but that seems like an acceptable loss since we now have LVI and CorrelatedValuePropagation to pick up
the slack. If you see conditional propagation that's not happening, please file bugs against LVI or CVP.
llvm-svn: 119714
refusing to optimize two memcpy's like this:
copy A <- B
copy C <- A
if it couldn't prove that noalias(B,C). We can eliminate
the copy by producing a memmove instead of memcpy.
llvm-svn: 119694
if it is passed as a byval argument. The byval argument will just be a
read, so it is safe to read from the original global instead. This allows
us to promote away the %agg.tmp alloca in PR8582
llvm-svn: 119686
and testing is easier. A good example is the unknown-location.ll test that
now can just look for ".loc 1 0 0". We also don't use a DW_LNE_set_address for
every address change anymore.
llvm-svn: 119613
It is generally not sufficient to check if the starting offset is in range
of the maximum offset that can be efficiently used for the target.
llvm-svn: 119565
This makes it more clear that the symbol is an internal, compiler-generated
name and gives a little more description about its contents.
llvm-svn: 119564
It was mistakenly looking at the pointer type when checking for the size of
global variables. This is a partial fix for Radar 8673120.
llvm-svn: 119563
and xor. The 32-bit move immediates can be hoisted out of loops by machine
LICM but the isel hacks were preventing them.
Instead, let peephole optimization pass recognize registers that are defined by
immediates and the ARM target hook will fold the immediates in.
Other changes include 1) do not fold and / xor into cmp to isel TST / TEQ
instructions if there are multiple uses. This happens when the 'and' is live
out, machine sink would have sinked the computation and that ends up pessimizing
code. The peephole pass would recognize situations where the 'and' can be
toggled to define CPSR and eliminate the comparison anyway.
2) Move peephole pass to after machine LICM, sink, and CSE to avoid blocking
important optimizations.
rdar://8663787, rdar://8241368
llvm-svn: 119548
instructions have to distinguish between lists of single- and double-precision
registers in order for the ASM matcher to do a proper job. In all other
respects, a list of single- or double-precision registers are the same as a list
of GPR registers.
llvm-svn: 119460
over a phi node by applying it to each operand may be wrong if the
operation and the phi node are mutually interdependent (the testcase
has a simple example of this). So only do this transform if it would
be correct to perform the operation in each predecessor of the block
containing the phi, i.e. if the other operands all dominate the phi.
This should fix the FFMPEG snow.c regression reported by İsmail Dönmez.
llvm-svn: 119347
The live range of a register defined by an early clobber starts at the use slot,
not the def slot.
Except when it is an early clobber tied to a use operand. Then it starts at the
def slot like a standard def.
llvm-svn: 119305
live ranges for the spill register are also defined at the use slot instead of
the normal def slot.
This fixes PR8612 for the inline spiller. A use was being allocated to the same
register as a spilled early clobber def.
This problem exists in all the spillers. A fix for the standard spiller is
forthcoming.
llvm-svn: 119182
variable if recursing fails to simplify it.
Factor AliasedSymbol to be a method of MCSymbol.
Update MCAssembler::EvaluateFixup to match the change in
EvaluateAsRelocatableImpl.
Remove the WeakRefExpr hack, as the object writer now sees the weakref with
no extra effort needed.
Nothing else is using MCTargetExpr, but keep it for now.
Now that the ELF writer sees relocations with aliases, handle
.weak foo2
foo2:
.weak bar2
.set bar2,foo2
.quad bar2
the same way gas does and produce a relocation with bar2.
llvm-svn: 119152
This moves most of the isUsed logic to the MCSymbol itself. With this we
get a bit more relaxed about allowing definitions after uses: uses that
don't evaluate their argument immediately (jmp foo) are accepted.
ddunbar, this was the smallest compromise I could think of that lets us
accept gcc (and clang!) assembly.
llvm-svn: 119144
offload the work to hasConstantValue rather than do something more
complicated (such handling mutually recursive phis) because (1) it is
not clear it is worth it; and (2) if it is worth it, maybe such logic
would be better placed in hasConstantValue. Adjust some GVN tests
which are now cleaned up much further (eg: all phi nodes are removed).
llvm-svn: 119043
SimplifyAssociativeOrCommutative) "(A op C1) op C2" -> "A op (C1 op C2)",
which previously was only done if C1 and C2 were constants, to occur whenever
"C1 op C2" simplifies (a la InstructionSimplify). Since the simplifying operand
combination can no longer be assumed to be the right-hand terms, consider all of
the possible permutations. When compiling "gcc as one big file", transform 2
(i.e. using right-hand operands) fires about 4000 times but it has to be said
that most of the time the simplifying operands are both constants. Transforms
3, 4 and 5 each fired once. Transform 6, which is an existing transform that
I didn't change, never fired. With this change, the testcase is now optimized
perfectly with one run of instcombine (previously it required instcombine +
reassociate + instcombine, and it may just have been luck that this worked).
llvm-svn: 119002
2. Fixing several errors in disassembler uncovered by test cases.
3. Fixing invalid encoding of PCMPEQ and PCMPNE uncovered by test cases.
llvm-svn: 118969
2. Parsing .word directive in MBlaze asm parser
3. Fixing hack where memory instructions reversed order of last two parameters
4. Fixing many improperly encoded instructions
5. Support parsing special instructions (MFS,MTS,etc.)
6. Removing unused functions from inst printer
llvm-svn: 118941
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
testing for dereferenceable pointers into a helper function,
isDereferenceablePointer. Teach it how to reason about GEPs
with simple non-zero indices.
Also eliminate ArgumentPromtion's IsAlwaysValidPointer,
which didn't check for weak externals or out of range gep
indices.
llvm-svn: 118840
references. For example, this allows gvn to eliminate the load in
this example:
void foo(int n, int* p, int *q) {
p[0] = 0;
p[1] = 1;
if (n) {
*q = p[0];
}
}
llvm-svn: 118714
nodes can be used in loops, this could result in infinite looping
if there is no recursion limit, so add such a limit. It is also
used for the SelectInst case because in theory there could be an
infinite loop there too if the basic block is unreachable.
llvm-svn: 118694
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
to optionally look for constant or local (alloca) memory.
Teach BasicAliasAnalysis::pointsToConstantMemory to look through Select
and Phi nodes, and to support looking for local memory.
Remove FunctionAttrs' PointsToLocalOrConstantMemory function, now that
AliasAnalysis knows all the tricks that it knew.
llvm-svn: 118412
of a select instruction, see if doing the compare with the
true and false values of the select gives the same result.
If so, that can be used as the value of the comparison.
llvm-svn: 118378
different forms of this instruction (movw/movl/movq) which we reported
as being ambiguous. Since they all do the same thing, gas just picks the
one with the shortest encoding. Follow its lead here.
This implements rdar://8208615
llvm-svn: 118362
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
shift-by-1 instructions, where the asmstring doesn't contain
the implicit 1. It turns out that a bunch of these rotate
instructions were completely broken because they used 1
instead of $1.
This fixes assembly mismatches on "rclb $1, %bl" and friends,
where we used to generate the 3 byte form, we now generate the
proper 2-byte form.
llvm-svn: 118355
floating point stack instructions instead of looking for b/w/l/q.
This fixes issues where we'd accidentally match fistp to fistpl,
when it is in fact an ambiguous instruction.
This changes the behavior of llvm-mc to reject fstp, which was the
correct fix for rdar://8456389:
t.s:1:1: error: ambiguous instructions require an explicit suffix (could be 'fstps', 'fstpl', or 'fstpt')
fstp (%rax)
it also causes us to correctly reject fistp and fist, which addresses
PR8528:
t.s:2:1: error: ambiguous instructions require an explicit suffix (could be 'fistps', or 'fistpl')
fistp (%rax)
^
t.s:3:1: error: ambiguous instructions require an explicit suffix (could be 'fists', or 'fistl')
fist (%rax)
^
Thanks to Ismail Donmez for tracking down the issue here!
llvm-svn: 118346
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
