llvm-svn: 47278

has plain one-result scalar integer multiplication instructions.
This avoids expanding such instructions into MUL_LOHI sequences that
must be special-cased at isel time, and avoids the problem with that
code that provented memory operands from being folded.

This fixes PR1874, addressesing the most common case. The uncommon
cases of optimizing multiply-high operations will require work
in DAGCombiner.

llvm-svn: 47277

to Dale for noticing this!

llvm-svn: 47276

llvm-svn: 47275

requested by Chris.  While there, do the same
for an existing function committed by someone
called "lattner" :)

llvm-svn: 47273

llvm-svn: 47272

that Object is an Argument before casting it to one.

llvm-svn: 47268

New helper function getMBBFromIndex() that given an index in any instruction of an MBB returns a pointer the MBB. Reviewed by Evan.

llvm-svn: 47267

Add support to GVN for performing sret return slot optimization.  This means that, if an sret function tail calls
another sret function, it should pass its own sret parameter to the tail callee, allowing it to fill in the correct
return value.  llvm-gcc does not emit this by default.  Instead, it allocates space in the caller for the sret of
the tail call and then uses memcpy to copy the result into the caller's sret parameter.  This optimization detects
and optimizes that case.

llvm-svn: 47265

llvm-svn: 47264

llvm-svn: 47263

For now, avoid commuting def MI for copy MI's whose source is not killed. That simply trade a live interval for another and because only the non-two-address operands can be folded into loads, may end up pessimising code.

llvm-svn: 47262

this speeds it up 2.3% on eon.

llvm-svn: 47261

llvm-svn: 47258

a function must be the first parameter.

llvm-svn: 47254

Fix a comment, and a bug where we weren't applying the tail call logic in cases that failed the first test.

llvm-svn: 47253

llvm-svn: 47252

llvm-svn: 47251

If we see a memcpy of a pointer, make sure to check later
uses of the pointer as well.

llvm-svn: 47250

llvm-svn: 47248

Also, noalias arguments are be considered "like" stack allocated ones for this purpose, because
the only way they can be modref'ed is if they escape somewhere in the current function.

llvm-svn: 47247

the second half of PR2047

llvm-svn: 47244

llvm-svn: 47242

that is also a subtract.  This implements PR2047 and Transforms/Reassociate/subtest2.ll 

llvm-svn: 47241

functionality change.

llvm-svn: 47239

llvm-svn: 47237

is not passed as an argument to a trampoline intrinsic.

llvm-svn: 47220

llvm-svn: 47219

I cannot find a libgcc function for this builtin.  Therefor expanding it to a noop (which is how it use to be treated).  If someone who knows the x86 backend better than me could tell me how to get a lock prefix on an instruction, that would be nice to complete x86 support.

llvm-svn: 47213

br_cc.  This fixes 5 "make check" failures.

llvm-svn: 47212

llvm-svn: 47208

llvm-svn: 47204

llvm-svn: 47200

it actually does. Simplify CountOperands a little by reusing
ComputeMemOperandsEnd. And reword some comments for both.

llvm-svn: 47198

llvm-svn: 47196

tblgen will complain if a sign-extended constant does not fit into a
data type smaller than i32, e.g., i16. This causes a problem when certain
hex constants are used, such as 0xff for byte masks or immediate xor
values.

tblgen will try the sign-extended value first and, if the sign extended
value would overflow, it tries to see if the unsigned value will fit.
Consequently, a software developer can now safely incant:

	(XORHIr16 R16C:$rA, 0xffff)

which is somewhat clearer and more informative than incanting:

	(XORHIr16 R16C:$rA, (i16 -1))

even if the two are bitwise equivalent.

Tblgen also outputs the 64-bit unsigned constant in the generated ISel code
when getTargetConstant() is invoked.

llvm-svn: 47188

llvm-svn: 47179

we had reached the "fake bucket" after the last bucket, allowing the iterator
in some cases to run off the end of the hashtable.

llvm-svn: 47178

with the TIED_TO attribute.

llvm-svn: 47177

that should be checked for the TIED_TO attribute instead of
using CountOperands.

llvm-svn: 47176