and handle incomplete control dependences correctly. This fixes:
Regression/Transforms/ADCE/dead-phi-edge.ll
-> a missed optimization
Regression/Transforms/ADCE/dead-phi-edge.ll
-> a compiler crash distilled from QT4
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20227 91177308-0d34-0410-b5e6-96231b3b80d8
* Properly compile this:
struct a {};
int test() {
struct a b[2];
if (&b[0] != &b[1])
abort ();
return 0;
}
to 'return 0', not abort().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19875 91177308-0d34-0410-b5e6-96231b3b80d8
The second folds operations into selects, e.g. (select C, (X+Y), (Y+Z))
-> (Y+(select C, X, Z)
This occurs a few times across spec, e.g.
select add/sub
mesa: 83 0
povray: 5 2
gcc 4 2
parser 0 22
perlbmk 13 30
twolf 0 3
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19706 91177308-0d34-0410-b5e6-96231b3b80d8
Disable the xform for < > cases. It turns out that the following is being
miscompiled:
bool %test(sbyte %S) {
%T = cast sbyte %S to uint
%V = setgt uint %T, 255
ret bool %V
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19628 91177308-0d34-0410-b5e6-96231b3b80d8
* We can now fold cast instructions into select instructions that
have at least one constant operand.
* We now optimize expressions more aggressively based on bits that are
known to be zero. These optimizations occur a lot in code that uses
bitfields even in simple ways.
* We now turn more cast-cast sequences into AND instructions. Before we
would only do this if it if all types were unsigned. Now only the
middle type needs to be unsigned (guaranteeing a zero extend).
* We transform sign extensions into zero extensions in several cases.
This corresponds to these test/Regression/Transforms/InstCombine testcases:
2004-11-22-Missed-and-fold.ll
and.ll: test28-29
cast.ll: test21-24
and-or-and.ll
cast-cast-to-and.ll
zeroext-and-reduce.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19220 91177308-0d34-0410-b5e6-96231b3b80d8
if the other side is overdefined.
This allows us to fold conditions like: if (X < Y || Y > Z) in some cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18807 91177308-0d34-0410-b5e6-96231b3b80d8
1. Actually increment the Statistic for the GV elim optzn
2. When resolving undef branches, only resolve branches in executable blocks,
avoiding marking a bunch of completely dead blocks live. This has a big
impact on the quality of the generated code.
With this patch, we positively rip up vortex, compiling Ut_MoveBytes to a
single memcpy call. In vortex we get this:
12 ipsccp - Number of globals found to be constant
986 ipsccp - Number of arguments constant propagated
1378 ipsccp - Number of basic blocks unreachable
8919 ipsccp - Number of instructions removed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18796 91177308-0d34-0410-b5e6-96231b3b80d8
In functions where we fully constant prop the return value, replace all
ret instructions with 'ret undef'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18786 91177308-0d34-0410-b5e6-96231b3b80d8
This implements SCCP/ipsccp-basic.ll, rips apart Olden/mst (as described in
PR415), and does other nice things.
There is still more to come with this, but it's a start.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18752 91177308-0d34-0410-b5e6-96231b3b80d8
successor block. This turns cases like this:
x = a op b
if (c) {
use x
}
into:
if (c) {
x = a op b
use x
}
This triggers 3965 times in spec, and is tested by
Regression/Transforms/InstCombine/sink_instruction.ll
This appears to expose a bug in the X86 backend for 177.mesa, which I'm
looking in to.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18677 91177308-0d34-0410-b5e6-96231b3b80d8
* Make sure we handle signed to unsigned conversion correctly
* Move this visitSetCondInst case to its own method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18312 91177308-0d34-0410-b5e6-96231b3b80d8
1. Speedup getValueState by having it not consider Arguments. It's better
to just add them before we start SCCP'ing.
2. SCCP can delete the contents of dead blocks. No really, it's ok! This
reduces the size of the IR for subsequent passes, even though
simplifycfg would do the same job. In practice, simplifycfg does not
run until much later than sccp in gccas
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17820 91177308-0d34-0410-b5e6-96231b3b80d8
class. The only changes are minor:
* Do not try to SCCP instructions that return void in the rewrite loop.
This is silly and fool hardy, wasting a map lookup and adding an entry
to the map which is never used.
* If we decide something has an undefined value, rewrite it to undef,
potentially leading to further simplications.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17816 91177308-0d34-0410-b5e6-96231b3b80d8
If this happens, detect it early instead of relying on instcombine to notice
it later. This can be a big speedup, because PHI nodes can have many
incoming values.
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This exposes subsequent optimization possiblities and reduces code size.
This triggers 1423 times in spec.
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%X = alloca ...
%Y = alloca ...
X == Y
into false. This allows us to simplify some stuff in eon (and probably
many other C++ programs) where operator= was checking for self assignment.
Folding this allows us to SROA several additional structs.
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of the array is just two. This occurs 8 times in gcc, 6 times in crafty, and
12 times in 099.go.
This implements ScalarRepl/sroa_two.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17727 91177308-0d34-0410-b5e6-96231b3b80d8
for (X * C1) + (X * C2) (where * can be mul or shl), allowing us to fold:
Y+Y+Y+Y+Y+Y+Y+Y
into
%tmp.8 = shl long %Y, ubyte 3 ; <long> [#uses=1]
instead of
%tmp.4 = shl long %Y, ubyte 2 ; <long> [#uses=1]
%tmp.12 = shl long %Y, ubyte 2 ; <long> [#uses=1]
%tmp.8 = add long %tmp.4, %tmp.12 ; <long> [#uses=1]
This implements add.ll:test25
Also add support for (X*C1)-(X*C2) -> X*(C1-C2), implementing sub.ll:test18
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17704 91177308-0d34-0410-b5e6-96231b3b80d8
loops. This optimization is not turned on by default yet, but may be run
with the opt tool's -loop-reduce flag. There are many FIXMEs listed in the
code that will make it far more applicable to a wide range of code, but you
have to start somewhere :)
This limited version currently triggers on the following tests in the
MultiSource directory:
pcompress2: 7 times
cfrac: 5 times
anagram: 2 times
ks: 6 times
yacr2: 2 times
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17134 91177308-0d34-0410-b5e6-96231b3b80d8
change hacks off 10K of bytecode from perlbmk (.5%) even though the front-end
is not generating them yet and we are not optimizing the resultant code.
This isn't too bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17111 91177308-0d34-0410-b5e6-96231b3b80d8
exercise that I'm not interested in tackling right now. Just punt and treat them
like unwind's.
This 'fixes' test/Regression/Transforms/ADCE/unreachable-function.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17106 91177308-0d34-0410-b5e6-96231b3b80d8
pointer recurrences into expressions from this:
%P_addr.0.i.0 = phi sbyte* [ getelementptr ([8 x sbyte]* %.str_1, int 0, int 0), %entry ], [ %inc.0.i, %no_exit.i ]
%inc.0.i = getelementptr sbyte* %P_addr.0.i.0, int 1 ; <sbyte*> [#uses=2]
into this:
%inc.0.i = getelementptr sbyte* getelementptr ([8 x sbyte]* %.str_1, int 0, int 0), int %inc.0.i.rec
Actually create something nice, like this:
%inc.0.i = getelementptr [8 x sbyte]* %.str_1, int 0, int %inc.0.i.rec
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16924 91177308-0d34-0410-b5e6-96231b3b80d8
an instruction if it can be hoisted to a common dominator of the block.
This implements: test/Regression/Transforms/TailDup/MergeTest.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16758 91177308-0d34-0410-b5e6-96231b3b80d8
* SubOne/AddOne functions always return ConstantInt, declare them as such
* Pull code for handling setcc X, cst, where cst is at the end of the range,
or cc is LE or GE up earlier in visitSetCondInst. This reduces #iterations
in some cases.
* Fold: (div X, C1) op C2 -> range check, implementing div.ll:test6 - test9.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16588 91177308-0d34-0410-b5e6-96231b3b80d8
This takes something like this:
%A = phi int [ 3, %cond_false.0 ], [ 2, %endif.0.i ], [ 2, %endif.1.i ]
%B = div int %tmp.243, 4
and turns it into:
%A = phi int [ 3/4, %cond_false.0 ], [ 2/4, %endif.0.i ], [ 2/4, %endif.1.i ]
which is later simplified (in this case) into %A = 0.
This triggers thousands of times in spec, for example, 269 times in 176.gcc.
This is tested by InstCombine/add.ll:test23 and set.ll:test18.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16582 91177308-0d34-0410-b5e6-96231b3b80d8
Instcombine (setcc (truncate X), C1).
This occurs THOUSANDS of times in many benchmarks. Particularlly common
seem to be things like (seteq (cast bool X to int), int 0)
This turns it into (seteq bool %X, false), which then becomes (not %X).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16567 91177308-0d34-0410-b5e6-96231b3b80d8
This is important for several reasons:
1. Benchmarks have lots of code that looks like this (perlbmk in particular):
%tmp.2.i = setne int %tmp.0.i, 128 ; <bool> [#uses=1]
%tmp.6343 = seteq int %tmp.0.i, 1 ; <bool> [#uses=1]
%tmp.63 = and bool %tmp.2.i, %tmp.6343 ; <bool> [#uses=1]
we now fold away the setne, a clear improvement.
2. In the more important cases, such as (X >= 10) & (X < 20), we now produce
smaller code: (X-10) < 10.
3. Perhaps the nicest effect of this patch is that it really helps out the
code generators. In particular, for a 'range test' like the above,
instead of generating this on X86 (the difference on PPC is even more
pronounced):
cmp %EAX, 50
setge %CL
cmp %EAX, 100
setl %AL
and %CL, %AL
cmp %CL, 0
we now generate this:
add %EAX, -50
cmp %EAX, 50
Furthermore, this causes setcc's to be folded into branches more often.
These combinations trigger dozens of times in the spec benchmarks, particularly
in 176.gcc, 186.crafty, 253.perlbmk, 254.gap, & 099.go.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16559 91177308-0d34-0410-b5e6-96231b3b80d8
Implement (setcc (shl X, C1), C2) folding.
The second one occurs several dozen times in spec. The first was added
just in case. :)
These are tested by shift.ll:test2[12], and div.ll:test5
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16549 91177308-0d34-0410-b5e6-96231b3b80d8
This latent bug was exposed by recent changes, and is tested as:
llvm/test/Regression/Transforms/InstCombine/2004-09-28-BadShiftAndSetCC.llx
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16546 91177308-0d34-0410-b5e6-96231b3b80d8
where we folded (X & 254) -> X < 1 instead of X < 2. These problems were
latent problems exposed by the latest patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16528 91177308-0d34-0410-b5e6-96231b3b80d8
triggers often, for example:
6x in povray, 1x in gzip, 279x in gcc, 1x in crafty, 8x in eon, 11x in perlbmk,
362x in gap, 4x in vortex, 14 in m88ksim, 211x in 126.gcc, 1x in compress,
11x in ijpeg, and 4x in 147.vortex.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16521 91177308-0d34-0410-b5e6-96231b3b80d8
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16137 91177308-0d34-0410-b5e6-96231b3b80d8
This also registers the pass with opt with a -lower-packed command line
option.
Patch contributed by Brad Jones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15987 91177308-0d34-0410-b5e6-96231b3b80d8
assumed that a constant on the RHS of a multiplication was either an
IntConstant or an FPConstant. It checked for an IntConstant and then,
if it did not find one, did a hard cast to an FPConstant. That code
would crash if the RHS were a ConstantExpr that was neither an
IntConstant nor an FPConstant. This version replaces the hard cast
with a dyn_cast. It performs the same way for IntConstants and
FPConstants but does nothing, instead of crashing, for constant
expressions.
The regression test for this change is 2004-07-27-ConstantExprMul.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15291 91177308-0d34-0410-b5e6-96231b3b80d8
a bug in DSE).
* Delete dead operand uses iteratively instead of recursively, using a
SetVector.
* Defer deletion of dead operand uses until the end of processing, which means
we don't have to bother with updating the AliasSetTracker. This speeds up
DSE substantially.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15204 91177308-0d34-0410-b5e6-96231b3b80d8
can be improved in many ways. But: stop laughing, even with -basicaa it
deletes 15% of the stores in 252.eon :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15101 91177308-0d34-0410-b5e6-96231b3b80d8
* Test for whether bits are shifted out during the optzn.
If so, the fold is illegal, though it can be handled explicitly for setne/seteq
This fixes the miscompilation of 254.gap last night, which was a latent bug
exposed by other optimizer improvements.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15085 91177308-0d34-0410-b5e6-96231b3b80d8
actually care about. Someday when the cast instruction is gone, we can do
better here, but this will do for now. This implements
instcombine/cast.ll:test17/18 as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15018 91177308-0d34-0410-b5e6-96231b3b80d8
Speed up SCCP substantially by processing overdefined values quickly. This
patch speeds up SCCP by about 30-40% on large testcases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14861 91177308-0d34-0410-b5e6-96231b3b80d8
"load (cast foo)". This allows us to compile C++ code like this:
class Bclass {
public: virtual int operator()() { return 666; }
};
class Dclass: public Bclass {
public: virtual int operator()() { return 667; }
} ;
int main(int argc, char** argv) {
Dclass x;
return x();
}
Into this:
int %main(int %argc, sbyte** %argv) {
entry:
call void %__main( )
ret int 667
}
Instead of this:
int %main(int %argc, sbyte** %argv) {
entry:
%x = alloca "struct.std::bad_typeid" ; <"struct.std::bad_typeid"*> [#uses=3]
call void %__main( )
%tmp.1.i.i = getelementptr "struct.std::bad_typeid"* %x, uint 0, uint 0, uint 0 ; <int (...)***> [#uses=1]
store int (...)** getelementptr ([3 x int (...)*]* %vtable for Bclass, int 0, long 2), int (...)*** %tmp.1.i.i
%tmp.3.i = getelementptr "struct.std::bad_typeid"* %x, int 0, uint 0, uint 0 ; <int (...)***> [#uses=1]
store int (...)** getelementptr ([3 x int (...)*]* %vtable for Dclass, int 0, long 2), int (...)*** %tmp.3.i
%tmp.5 = load int ("struct.std::bad_typeid"*)** cast (int (...)** getelementptr ([3 x int (...)*]* %vtable for Dclass, int 0, long 2) to int
("struct.std::bad_typeid"*)**) ; <int ("struct.std::bad_typeid"*)*> [#uses=1]
%tmp.6 = call int %tmp.5( "struct.std::bad_typeid"* %x ) ; <int> [#uses=1]
ret int %tmp.6
ret int 0
}
In order words, we now resolve the virtual function call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14783 91177308-0d34-0410-b5e6-96231b3b80d8
Don't touch GEPs for which DecomposeArrayRef is not going to do anything
special (e.g., < 2 indices, or 2 indices and the last one is a constant.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14647 91177308-0d34-0410-b5e6-96231b3b80d8
Also, remove X % -1 = 0, because it's not true for unsigneds, and the
signed case is superceeded by this new handling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14637 91177308-0d34-0410-b5e6-96231b3b80d8
was processing blocks in whatever order they happened to end up in the
dominator tree data structure. Force an ordering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14248 91177308-0d34-0410-b5e6-96231b3b80d8
186.crafty, fhourstones and 132.ijpeg.
Bugpoint makes really nasty miscompilations embarassingly easy to find. It
narrowed it down to the instcombiner and this testcase (from fhourstones):
bool %l7153_l4706_htstat_loopentry_2E_4_no_exit_2E_4(int* %i, [32 x int]* %works, int* %tmp.98.out) {
newFuncRoot:
%tmp.96 = load int* %i ; <int> [#uses=1]
%tmp.97 = getelementptr [32 x int]* %works, long 0, int %tmp.96 ; <int*> [#uses=1]
%tmp.98 = load int* %tmp.97 ; <int> [#uses=2]
%tmp.99 = load int* %i ; <int> [#uses=1]
%tmp.100 = and int %tmp.99, 7 ; <int> [#uses=1]
%tmp.101 = seteq int %tmp.100, 7 ; <bool> [#uses=2]
%tmp.102 = cast bool %tmp.101 to int ; <int> [#uses=0]
br bool %tmp.101, label %codeRepl4.exitStub, label %codeRepl3.exitStub
codeRepl4.exitStub: ; preds = %newFuncRoot
store int %tmp.98, int* %tmp.98.out
ret bool true
codeRepl3.exitStub: ; preds = %newFuncRoot
store int %tmp.98, int* %tmp.98.out
ret bool false
}
... which only has one combination performed on it:
$ llvm-as < t.ll | opt -instcombine -debug | llvm-dis
IC: Old = %tmp.101 = seteq int %tmp.100, 7 ; <bool> [#uses=1]
New = setne int %tmp.100, 0 ; <bool>:<badref> [#uses=0]
IC: MOD = br bool %tmp.101, label %codeRepl3.exitStub, label %codeRepl4.exitStub
IC: MOD = %tmp.97 = getelementptr [32 x int]* %works, uint 0, int %tmp.96 ; <int*> [#uses=1]
It doesn't get much better than this. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14109 91177308-0d34-0410-b5e6-96231b3b80d8
collapse this:
bool %le(int %A, int %B) {
%c1 = setgt int %A, %B
%tmp = select bool %c1, int 1, int 0
%c2 = setlt int %A, %B
%result = select bool %c2, int -1, int %tmp
%c3 = setle int %result, 0
ret bool %c3
}
into:
bool %le(int %A, int %B) {
%c3 = setle int %A, %B ; <bool> [#uses=1]
ret bool %c3
}
which is handy, because the Java FE makes these sequences all over the place.
This is tested as: test/Regression/Transforms/InstCombine/JavaCompare.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14086 91177308-0d34-0410-b5e6-96231b3b80d8
This code hadn't been updated after the "structs with more than 256 elements"
related changes to the GEP instruction. Also it was not handling the
ConstantAggregateZero class.
Now it does!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13834 91177308-0d34-0410-b5e6-96231b3b80d8
into (X & (C2 << C1)) != (C3 << C1), where the shift may be either left or
right and the compare may be any one.
This triggers 1546 times in 176.gcc alone, as it is a common pattern that
occurs for bitfield accesses.
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in the size calculation.
This is not something you want to see:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - UNROLLING!
The problem was that 2*2147483648 == 0.
Now we get:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - TOO LARGE: 4294967296>100
Thanks to some anonymous person playing with the demo page that repeatedly
caused zion to go into swapping land. That's one way to ensure you'll get
a quick bugfix. :)
Testcase here: Transforms/LoopUnroll/2004-05-13-DontUnrollTooMuch.ll
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%tmp.0 = getelementptr [50 x sbyte]* %ar, uint 0, int 5 ; <sbyte*> [#uses=2]
%tmp.7 = getelementptr sbyte* %tmp.0, int 8 ; <sbyte*> [#uses=1]
together. This patch actually allows us to simplify and generalize the code.
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is only used by a cast, and the casted type is the same size as the original
allocation, it would eliminate the cast by folding it into the allocation.
Unfortunately, it was placing the new allocation instruction right before
the cast, which could pull (for example) alloca instructions into the body
of a function. This turns statically allocatable allocas into expensive
dynamically allocated allocas, which is bad bad bad.
This fixes the problem by placing the new allocation instruction at the same
place the old one was, duh. :)
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loop. This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall. Tommorows test
results will tell. :)
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over its USES. If it's dead it doesn't have any uses! :)
Thanks to the fabulous and mysterious Bill Wendling for pointing this out. :)
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structure to being dynamically computed on demand. This makes updating
loop information MUCH easier.
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that the exit block of the loop becomes the new entry block of the function.
This was causing a verifier assertion on 252.eon.
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block. The primary motivation for doing this is that we can now unroll nested loops.
This makes a pretty big difference in some cases. For example, in 183.equake,
we are now beating the native compiler with the CBE, and we are a lot closer
with LLC.
I'm now going to play around a bit with the unroll factor and see what effect
it really has.
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