don't make i1 phis when it won't be possible to eliminate them.

llvm-svn: 52097

Speculatively execute a block when the the block is the then part of a triangle shape and it contains a single, side effect free, cheap instruction. The branch is eliminated by adding a select instruction. i.e.

Turn                                                                                                                                                                                                       
BB:                                                                                                                                                                                                        
    %t1 = icmp                                                                                                                                                                                             
    br i1 %t1, label %BB1, label %BB2                                                                                                                                                                      
BB1:                                                                                                                                                                                                       
    %t3 = add %t2, c                                                                                                                                                                                       
    br label BB2                                                                                                                                                                                           
BB2:                                                                                                                                                                                                       
=>                                                                                                                                                                                                         
BB:                                                                                                                                                                                                        
    %t1 = icmp                                                                                                                                                                                             
    %t4 = add %t2, c                                                                                                                                                                                       
    %t3 = select i1 %t1, %t2, %t3

llvm-svn: 52073

llvm-svn: 52053

and better control the abstraction.  Rename the type
to MVT.  To update out-of-tree patches, the main
thing to do is to rename MVT::ValueType to MVT, and
rewrite expressions like MVT::getSizeInBits(VT) in
the form VT.getSizeInBits().  Use VT.getSimpleVT()
to extract a MVT::SimpleValueType for use in switch
statements (you will get an assert failure if VT is
an extended value type - these shouldn't exist after
type legalization).
This results in a small speedup of codegen and no
new testsuite failures (x86-64 linux).

llvm-svn: 52044

otherwise, opt might crash.

llvm-svn: 52041

crash the opt. Just fix this.

Test case in llvm/test/Transforms/InstCombine/2008-06-05-ashr-crash.ll

llvm-svn: 52003

work and how to replace them into individual values. Also, when trying to
replace an aggregrate that is used by load or store with a single (large)
integer, don't crash (but don't replace the aggregrate either).

Also adds a testcase for both structs and arrays.

llvm-svn: 51997

not other instructions. This fixes a crash with the added testcase.

llvm-svn: 51992

passing its pointer. Fixes test with added testcase.

llvm-svn: 51991

function is passed as an argument instead of called. Also do this check a bit
earlier.

llvm-svn: 51990

deprecated by the GVN and GVNPRE passes.

llvm-svn: 51983

llvm-svn: 51955

llvm-svn: 51947

are the same as in unpacked structs, only field
positions differ.  This only matters for structs
containing x86 long double or an apint; it may
cause backwards compatibility problems if someone
has bitcode containing a packed struct with a
field of one of those types.
The issue is that only 10 bytes are needed to
hold an x86 long double: the store size is 10
bytes, but the ABI size is 12 or 16 bytes (linux/
darwin) which comes from rounding the store size
up by the alignment.  Because it seemed silly not
to pack an x86 long double into 10 bytes in a
packed struct, this is what was done.  I now
think this was a mistake.  Reserving the ABI size
for an x86 long double field even in a packed
struct makes things more uniform: the ABI size is
now always used when reserving space for a type.
This means that developers are less likely to
make mistakes.  It also makes life easier for the
CBE which otherwise could not represent all LLVM
packed structs (PR2402).
Front-end people might need to adjust the way
they create LLVM structs - see following change
to llvm-gcc.

llvm-svn: 51928

Don't crash when we encounter one of these.

llvm-svn: 51915

llvm-svn: 51890

llvm-svn: 51887

llvm-svn: 51864

out of instcombine into a new file in libanalysis.  This also teaches
ComputeNumSignBits about the number of sign bits in a constantint.

llvm-svn: 51863

char a[200];
init(a, a+200);

OR

int a[200];
char* b = (char*)a;
char* c = (char*)a;
foo(b, c);

llvm-svn: 51850

llvm-svn: 51848

the conditions for performing the transform when only the
function declaration is available: no longer allow turning
i32 into i64 for example.  Only allow changing between
pointer types, and between pointer types and integers of
the same size.  For return values ptr -> intptr was already
allowed; I added ptr -> ptr and intptr -> ptr while there.
As shown by a recent objc testcase, changing the way
parameters/return values are passed can be fatal when calling
code written in assembler that directly manipulates call
arguments and return values unless the transform has no
impact on the way they are passed at the codegen level.
While it is possible to imagine an ABI that treats integers
of pointer size differently to pointers, I don't think LLVM
supports any so the transform should now be safe while still
being useful.

llvm-svn: 51834

llvm-svn: 51819

llvm-svn: 51817

llvm-svn: 51816

llvm-svn: 51789

Since LCSSA switched over to DenseMap, we have to be more careful to avoid iterator invalidation.  Fixes PR2385.

llvm-svn: 51777

llvm-svn: 51770

llvm-svn: 51698

llvm-svn: 51680

the one case that ADCE catches that normal DCE doesn't: non-induction variable
loop computations.

This implementation handles this problem without using postdominators.

llvm-svn: 51668

llvm-svn: 51666

llvm-svn: 51663

llvm-svn: 51636

llvm-svn: 51591

the set of nodes. Fix makeEqual to handle this by creating the new node first
then iterating across them second.

llvm-svn: 51573

llvm-svn: 51572

the section or the visibility from one global
value to another: copyAttributesFrom.  This is
particularly useful for duplicating functions:
previously this was done by explicitly copying
each attribute in turn at each place where a
new function was created out of an old one, with
the result that obscure attributes were regularly
forgotten (like the collector or the section).
Hopefully now everything is uniform and nothing
is forgotten.

llvm-svn: 51567

llvm-svn: 51565

Analysis/ConstantFolding to fold ConstantExpr's, then make instcombine use it
to try to use targetdata to fold constant expressions on void instructions.

Also extend the icmp(inttoptr, inttoptr) folding to handle the case where
int size != ptr size.

llvm-svn: 51559