Commit Graph

2199 Commits

Author SHA1 Message Date
Owen Anderson
fa113f8155 Factor the profitability check for return slot optimization out into a static function.
At some point in the future, this check will become smarter.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47310 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19 03:27:34 +00:00
Owen Anderson
c0755a6f98 An sret parameter is required to be the first parameter, so there's no need to loop
over all the parameters of the callee looking for it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47309 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19 03:15:29 +00:00
Owen Anderson
7acc0af95a Cleanup some of my patches from yesterday. Refactor the check for which xform
to apply to a memcpy into processInstruction.  Also, fix a bug in the check due to
missing braces.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47307 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19 03:09:45 +00:00
Owen Anderson
c2580ab9b0 Fix Transforms/GVN/memcpy.ll, which Chris broke in r47275 by reordering the branches. memcpy's are a kind of CallInst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47305 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19 02:53:23 +00:00
Nick Lewycky
e0cfecf47d Correctly fold divide-by-constant, even when faced with overflow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47287 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 22:48:05 +00:00
Chris Lattner
e10c0b9d66 Transforming -A + -B --> -(A + B) isn't safe for FP, thanks
to Dale for noticing this!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47276 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 17:50:16 +00:00
Chris Lattner
913b19f6fc minor code simplification, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47275 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 17:47:29 +00:00
Owen Anderson
5aa4f2a085 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47265 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 09:24:53 +00:00
Chris Lattner
bf1d8a7099 optimize away stackrestore calls that have no intervening alloca or call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47258 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 06:12:38 +00:00
Chris Lattner
d5b8d92b9f simplify some code, BreakUpSubtract always returns nonnull now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 02:18:25 +00:00
Chris Lattner
dd12f96c5e Fold (-x + -y) -> -(x+y) which promotes better association, fixing
the second half of PR2047


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47244 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-17 21:03:36 +00:00
Chris Lattner
5329bb22e9 fix pasto
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47242 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-17 20:54:40 +00:00
Chris Lattner
0b0803ae15 Split up subtracts into add+negate if they have a reassociable use or operand
that is also a subtract.  This implements PR2047 and Transforms/Reassociate/subtest2.ll 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47241 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-17 20:51:26 +00:00
Chris Lattner
9bc5ed78c8 make the logic for breaking up subtracts more explicit, no
functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47239 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-17 20:44:51 +00:00
Devang Patel
9d9b204d6a Fix PR2028
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47150 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-15 01:24:49 +00:00
Devang Patel
9b03daa2a3 If loop header is also loop exiting block then OrigPN is incoming value for B loop header.
Fixes PR 2030.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47141 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 23:18:47 +00:00
Chris Lattner
13daadbd25 simplify code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47116 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 07:39:01 +00:00
Nick Lewycky
95f0ba2703 Fix PR2032. Inform the alias analysis of changes to the underlying program.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47111 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 07:11:24 +00:00
Devang Patel
ea06906559 A loop latch phi node may have uses inside loop, not just in loop header.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47093 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 22:23:07 +00:00
Dan Gohman
7649127ec1 Rename APInt's isPositive to isNonNegative, to reflect what it
actually does.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47090 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 22:09:18 +00:00
Devang Patel
23067dfeac While moving exit condition, do not drop loop latch on the floor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47089 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 22:06:36 +00:00
Devang Patel
02c4836f3d Keep track of exit value operand number when operands are swapped.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47082 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 19:48:48 +00:00
Owen Anderson
30b4bd4d10 Re-apply the patch to improve the optimizations of memcpy's, with several
bugs fixed.  This now passes PPC bootstrap.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47026 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 21:15:18 +00:00
Eli Friedman
b6c36e4058 Fix for bug 1996: optimize out loads of undef. This code basically just
checks for a malloc/alloca immediately followed by a load.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47006 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 12:08:14 +00:00
Chris Lattner
916c954bf2 Fix scalarrepl to not 'miscompile' undefined code, part #2.
This fixes the store case, my previous patch just fixed the load
case.  rdar://5707076.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46932 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-10 19:05:37 +00:00
Devang Patel
82ada54da0 Fix PR 1995.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46898 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-08 22:49:13 +00:00
Bill Wendling
e00fec554b Temporarily reverting:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20080128/057882.html

This is causing a miscompilation on PPC G5 and just now seeing it on iMac x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46822 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-06 20:03:07 +00:00
Chris Lattner
7c95debb49 Fix a bug compiling PR1978 (perhaps not the only one though) which
was incorrectly simplifying "x == (gep x, 1, i)" into false, even 
though i could be negative.  As it turns out, all the code to 
handle this already existed, we just need to disable the incorrect
optimization case and let the general case handle it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46739 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-05 04:45:32 +00:00
Owen Anderson
c69ace3a64 Be more precise when eliminating pointers bue to memcpy's. This allows more
stores to be deleted in some cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46694 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04 04:53:00 +00:00
Owen Anderson
6f7a52d300 Allow GVN to hack on memcpy's, making them open to further optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46693 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04 02:59:58 +00:00
Nick Lewycky
5be2920149 There are some cases where icmp(add) can be folded into a new icmp. Handle them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46687 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-03 16:33:09 +00:00
Nick Lewycky
0c2c3f6e81 Hack on vectors too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46684 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-03 08:19:11 +00:00
Nick Lewycky
b6eabff169 Fold away one multiply in instcombine. This would normally be caught in
reassociate anyways, but they could be generated during instcombine's run.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46683 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-03 07:42:09 +00:00
Nick Lewycky
b4b0417220 Remove a couple more cases of "getNumUses() == 0". No need to walk the linked
list just to see if whether the list is empty.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46555 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 08:01:28 +00:00
Nick Lewycky
c7444498ee Use empty() instead of comparing size() with zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46554 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 07:54:16 +00:00
Nick Lewycky
d29ce1783c Don't DCE FreeInst's. We were using those! Patch from Owen Anderson.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46553 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 07:45:37 +00:00
Owen Anderson
772601a885 Make DSE much more aggressive by performing DCE earlier. Update a testcase to reflect this increased aggressiveness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46542 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 01:24:47 +00:00
Chris Lattner
b10e0da065 Fix a bug where scalarrepl would discard offset if type would match.
In practice this can only happen on code with already undefined behavior, 
but this is still a good thing to handle correctly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46539 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 00:39:15 +00:00
Dan Gohman
3035959425 Use empty() instead of comparing size() with zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46514 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 13:02:09 +00:00
Chris Lattner
2454a2e0c3 eliminate additions of 0.0 when they are obviously dead. This has to be careful to
avoid turning -0.0 + 0.0 -> -0.0 which is incorrect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 06:52:45 +00:00
Owen Anderson
a34d8a0d83 Add support for eliminating memcpy's at the end of functions. Also fix some errors I noticed in
the handling of eliminating stores to byval arguments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46494 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 06:18:36 +00:00
Devang Patel
c840da14c6 Filter loops that subtract induction variables.
These loops are not yet handled.

Fix PR 1912.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46484 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 02:20:41 +00:00
Nick Lewycky
4189a538e4 Handle some more combinations of extend and icmp. Fixes PR1940.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46431 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-28 03:48:02 +00:00
Chris Lattner
25feae555d Fix PR1932 by disabling an xform invalid for fdiv.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46429 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-28 00:58:18 +00:00
Chris Lattner
05bb789430 Fix PR1938 by forcing the code that uses an undefined value to branch one
way or the other.  Rewriting the code itself prevents subsequent analysis
passes from making contradictory conclusions about the code that could 
cause an infeasible path to be made feasible.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46427 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-28 00:32:30 +00:00
Nick Lewycky
c837abee2f Be more careful modifying the use_list while also iterating through it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46417 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-27 18:35:00 +00:00
Bill Wendling
beefd3d0f8 The CorrelatedExpressionElimination pass is known to be buggy. Remove it.
This fixes PR1769.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46408 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-27 06:11:41 +00:00
Chris Lattner
b753065f6d Fold fptrunc(add (fpextend x), (fpextend y)) -> add(x,y), as GCC does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46406 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-27 05:29:54 +00:00
Bill Wendling
381802f8e0 If there are no machine instructions emitted for a function, then insert
a "nop" instruction so that we don't have the function's label associated
with something that it's not supposed to be associated with.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46394 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-26 06:51:24 +00:00
Bill Wendling
f69d5d7398 If we have a function like this:
void bork() {
  int *address = 0;
  *address = 0;
}

It's compiled into LLVM code that looks like this:

define void @bork() noreturn nounwind  {
entry:
        unreachable
}

This is bad on some platforms (like PPC) because it will generate the label for
the function but no body. The label could end up being associated with some
non-code related stuff, like a section. This places a "trap" instruction if the
SimplifyCFG pass removed all code from the function leaving only one
"unreachable" instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46387 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-26 01:43:44 +00:00